1
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Korsaye FA, Perrella F, Petrone A, Adamo C, Rega N, Ciofini I. Monitoring Density Redistribution at the Excited State in a Dual Emitting Molecule: An Analysis Based on Real-Time Density Functional Theory and Density Descriptors. J Phys Chem A 2024; 128:4324-4334. [PMID: 38758031 DOI: 10.1021/acs.jpca.4c00934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
In this work, we computed and analyzed, by means of density-based descriptors, the real-time evolution of both the locally excited (LE) and charge-transfer (CT) excited states for the planar and twisted conformations of the DMABN (4-(N,N-dimethylamino)benzonitrile) molecule using real-time time-dependent density functional theory (DFT) and three different exchange-correlation energy functionals (EXC) belonging to the same family (the PBE one). Our results based on the analysis of density-based descriptors show that the underlying EXC modifies the evolution in time of the density. In particular, comparing the frequency of density reorganization computed with the three functionals (PBE, PBE0, and LC-PBE), we found that the frequency of electronic interconversion of the individual determinants involved during the dynamics increases from PBE to PBE0 and to LC-PBE. This allows us to show that there is a correlation between the delocalization of the electronic density and the frequency of reorganization. In particular, the greater the mean hole-electron distance during the dynamics, the lower is the frequency of density reorganization.
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Affiliation(s)
- Feven-Alemu Korsaye
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, F-75005 Paris, France
| | - Fulvio Perrella
- Scuola Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italia
| | - Alessio Petrone
- Scuola Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italia
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, via Cintia 21, I-80126 Napoli, Italia
- Istituto Nazionale di Fisica Nucleare, Unità di Napoli, via Cintia 21, I-80126 Napoli, Italia
| | - Carlo Adamo
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, F-75005 Paris, France
| | - Nadia Rega
- Scuola Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italia
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, via Cintia 21, I-80126 Napoli, Italia
- Istituto Nazionale di Fisica Nucleare, Unità di Napoli, via Cintia 21, I-80126 Napoli, Italia
| | - Ilaria Ciofini
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, F-75005 Paris, France
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2
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Shaalan Alag A, Szalay PG, Tajti A. Ab initio investigation of excited state charge transfer pathways in differently capped bithiophene cages. J Comput Chem 2024; 45:1078-1086. [PMID: 38241483 DOI: 10.1002/jcc.27307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/27/2023] [Accepted: 12/15/2023] [Indexed: 01/21/2024]
Abstract
The electronic excitations of conformationally constrained bithiophene cage systems as previously investigated by Lewis et al. (J. Am. Chem. Soc. 143, 18548 (2021)) are revisited, employing the correlated ab initio Scaled Opposite-Spin Algebraic Diagrammatic Construction Second Order electronic structure method. Quantitative descriptors are determined to assess the extent of charge transfer between the bithiophene moieties and the capping domains, represented by either phenyl or triazine groups. The investigation substantiates intrinsic differences in the photophysical behavior of these two structural variants and reveals the presence of lower-energy excited states characterized by noteworthy charge transfer contributions in the triazine cage system. The manifestation of this charge transfer character is discernible even at the Franck-Condon geometry, persisting throughout the relaxation of the excited state. By examining isolated monomer building blocks, we confirm the existence of analogous charge transfer contributions in their excitations. Employing this methodological approach facilitates the prospective identification of potential wall/cap chromophore pairs, wherein charge transfer pathways can be accessed within the energetically favorable regime.
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Affiliation(s)
- Ahmed Shaalan Alag
- Laboratory of Theoretical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Péter G Szalay
- Laboratory of Theoretical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Attila Tajti
- Laboratory of Theoretical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
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3
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Mazumder A, Vinod K, Maret PD, Das PP, Hariharan M. Symmetry-Breaking Charge Separation Mediated Triplet Population in a Perylenediimide Trimer at the Single-Molecule Level. J Phys Chem Lett 2024:5896-5904. [PMID: 38805687 DOI: 10.1021/acs.jpclett.4c01201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Herein, we demonstrate triplet excited-state population in a conformationally rigid perylenediimide trimer (PDI-T) via intramolecular symmetry-breaking charge separation (SB-CS) at the single-molecule level. The single-molecule fluorescence intensity trajectories of PDI-T in nonpolar polystyrene matrix (ε = 2.60) exhibit prolonged fluorescence with infrequent dark states, representing the triplet and/or the charge transfer states. In contrast, in a poly(vinyl alcohol) matrix (ε = 7.80), erratic blinking dynamics resulting in low photon counts were observed, corroborating the feasibility of charge separation in a polar environment. In agreement with the single-molecule measurements, transient absorption spectroscopy of PDI-T reveals ultrafast SB-CS (τCS < 5 ps) in polar tetrahydrofuran (ε = 7.58) and acetone (ε = 20.70), with the population of the triplet excited-state through charge recombination. The current investigation shows the utility of rigid and weakly coupled molecular constructs in controlling triplet generation and SB-CS for potential applications in optoelectronic devices.
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Affiliation(s)
- Aniruddha Mazumder
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Kavya Vinod
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Philip Daniel Maret
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Pallavi Panthakkal Das
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
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4
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Jodra A, Marazzi M, Frutos LM, García-Iriepa C. Modulating Efficiency and Color of Thermally Activated Delayed Fluorescence by Rationalizing the Substitution Effect. J Chem Theory Comput 2024; 20:4239-4253. [PMID: 38738688 DOI: 10.1021/acs.jctc.4c00009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
Thermally activated delayed fluorescence (TADF) constitutes the process by which third-generation organic light-emitting diodes (OLEDs) are being designed and produced. Despite several years of trial-and-error attempts, mainly driven by chemical intuition about how to improve a certain aspect of the process, few studies focused on the in-depth description of its two key properties: efficiency of the T1 → S1 intersystem crossing and further S1 → S0 emission. Here, by means of a newly developed theoretical formalism, we propose a systematic rationalization of the substituent effect in a paradigmatic class of OLED compounds, based on phenothiazine-dibenzothiophene-S,S-dioxide, known as PTZ-DBTO2. Our methodology allows to discern among geometrical and electronic effects induced by the substituent, deeply understanding the relationships existing between charge transfer, spin density, geometrical deformations, and energy modulations between electronic states. By our results, we can finally elucidate, depending on the substituent, the fate of the overall TADF process, quantitatively assessing its efficiency and predicting the color emission. Moreover, the general terms by which this methodology was developed allow its application to any chromophore of interest.
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Affiliation(s)
- Alejandro Jodra
- Departamento de Química Analítica, Química Física e Ingeniería Química, Grupo de Reactividad y Estructura Molecular (RESMOL), Universidad de Alcalá, Ctra. Madrid-Barcelona, Km 33.600, Alcalá de Henares, Madrid 28871, Spain
| | - Marco Marazzi
- Departamento de Química Analítica, Química Física e Ingeniería Química, Grupo de Reactividad y Estructura Molecular (RESMOL), Universidad de Alcalá, Ctra. Madrid-Barcelona, Km 33.600, Alcalá de Henares, Madrid 28871, Spain
- Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, Ctra. Madrid-Barcelona, Km 33.600, Alcalá de Henares, Madrid 28871, Spain
| | - Luis Manuel Frutos
- Departamento de Química Analítica, Química Física e Ingeniería Química, Grupo de Reactividad y Estructura Molecular (RESMOL), Universidad de Alcalá, Ctra. Madrid-Barcelona, Km 33.600, Alcalá de Henares, Madrid 28871, Spain
- Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, Ctra. Madrid-Barcelona, Km 33.600, Alcalá de Henares, Madrid 28871, Spain
| | - Cristina García-Iriepa
- Departamento de Química Analítica, Química Física e Ingeniería Química, Grupo de Reactividad y Estructura Molecular (RESMOL), Universidad de Alcalá, Ctra. Madrid-Barcelona, Km 33.600, Alcalá de Henares, Madrid 28871, Spain
- Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, Ctra. Madrid-Barcelona, Km 33.600, Alcalá de Henares, Madrid 28871, Spain
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5
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Cole HD, Vali A, Roque JA, Shi G, Talgatov A, Kaur G, Francés-Monerris A, Alberto ME, Cameron CG, McFarland SA. Ru(II) Oligothienyl Complexes with Fluorinated Ligands: Photophysical, Electrochemical, and Photobiological Properties. Inorg Chem 2024; 63:9735-9752. [PMID: 38728376 DOI: 10.1021/acs.inorgchem.3c04382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024]
Abstract
A series of Ru(II) complexes incorporating two 4,4'-bis(trifluoromethyl)-2,2'-bipyridine (4,4'-btfmb) coligands and thienyl-appended imidazo[4,5-f][1,10]phenanthroline (IP-nT) ligands was characterized and assessed for phototherapy effects toward cancer cells. The [Ru(4,4'-btfmb)2(IP-nT)]2+ scaffold has greater overall redox activity compared to Ru(II) polypyridyl complexes such as [Ru(bpy)3]2+. Ru-1T-Ru-4T have additional oxidations due to the nT group and additional reductions due to the 4,4'-btfmb ligands. Ru-2T-Ru-4T also exhibit nT-based reductions. Ru-4T exhibits two oxidations and eight reductions within the potential window of -3 to +1.5 V. The lowest-lying triplets (T1) for Ru-0T-2T are metal-to-ligand charge-transfer (3MLCT) excited states with lifetimes around 1 μs, whereas T1 for Ru-3T-4T is longer-lived (∼20-24 μs) and of significant intraligand charge-transfer (3ILCT) character. Phototoxicity toward melanoma cells (SK-MEL-28) increases with n, with Ru-4T having a visible EC50 value as low as 9 nM and PI as large as 12,000. Ru-3T and Ru-4T retain some of this activity in hypoxia, where Ru-4T has a visible EC50 as low as 35 nM and PI as high as 2900. Activity over six biological replicates is consistent and within an order of magnitude. These results demonstrate the importance of lowest-lying 3ILCT states for phototoxicity and maintaining activity in hypoxia.
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Affiliation(s)
- Houston D Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Abbas Vali
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - John A Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Ge Shi
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Alisher Talgatov
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Gurleen Kaur
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | | | - Marta E Alberto
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende 87036, Italy
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
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6
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Vinod K, Jadhav SD, Hariharan M. Room Temperature Phosphorescence in Crystalline Iodinated Eumelanin Monomer. Chemistry 2024; 30:e202400499. [PMID: 38502668 DOI: 10.1002/chem.202400499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 03/01/2024] [Accepted: 03/19/2024] [Indexed: 03/21/2024]
Abstract
We report the room temperature phosphorescence upon iodination on a crystalline eumelanin monomer with shielded hydroxyl moieties, ethyl 5,6-dimethoxyindole-2-carboxylate (DMICE). Ultrafast intersystem crossing (ISC) is observed in the iodinated (IDMICE) as well as brominated (BDMICE) analogues of the eumelanin monomer derivative in solution. The triplet quantum yields (φT) and intersystem crossing rates (kISC) of the halogenated eumelanin derivatives areφ T B D M I C E ${{\phi{} }_{T}^{BDMICE}}$ =25.4±1.1 %;k I S C B D M I C E ${{k}_{ISC}^{BDMICE}}$ =1.95×109 s-1 andφ T I D M I C E ${{\phi{} }_{T}^{IDMICE}}$ =59.1±1.6 %;k I S C I D M I C E = ${{k}_{ISC}^{IDMICE}=}$ 1.36×1010 s-1, as monitored using transient absorption spectroscopy. Theoretical calculations based on nuclear ensemble method reveal that computed kISC and spin-orbit coupling matrix elements for eumelanin derivatives are larger for IDMICE relative to BDMICE. The halogen and π-π interactions, with distinct excitonic coupling and higher ISC rate promote phosphorescence in IDMICE molecular crystals. Accessing triplet excited states and resultant photoluminescence through structural modification of eumelanin scaffolds paves way for exploring the versatility of eumelanin-inspired molecules as bio-functional materials.
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Affiliation(s)
- Kavya Vinod
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram, 695551, Kerala, India
| | - Sohan D Jadhav
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram, 695551, Kerala, India
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram, 695551, Kerala, India
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7
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Belletto D, Ponte F, Mazzone G, Sicilia E. A detailed density functional theory exploration of the photodissociation mechanism of ruthenium complexes for photoactivated chemotherapy. Dalton Trans 2024; 53:8243-8253. [PMID: 38654633 DOI: 10.1039/d4dt00834k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Polypyridyl Ru(II) complexes have attracted much attention due to their potential as light-activatable anticancer agents in photoactivated chemotherapy (PACT). The action of ruthenium-based PACT compounds relies on the breaking of a coordination bond between the metal center and an organic ligand via a photosubstitution reaction. Here, a detailed computational investigation of the photophysical properties of a novel trisheteroleptic ruthenium complex, [Ru(dpp)(bpy)(mtmp)]2+ (dpp = 4,7-diphenyl-1,10-phenanthroline, bpy = 2,2'-bipyridine and mtmp = 2-methylthiomethylpyridine), has been carried out by means of DFT and its time-dependent extension. All the aspects of the mechanism by which, upon light irradiation, the mtmp protecting group is released and the corresponding aquated complex, able to bind to DNA inducing cell death, is formed have been explored in detail. All the involved singlet and triplet states have been fully described, providing the calculation of the corresponding energy barriers. The involvement of solvent molecules in photosubstitution and the role played by pyridyl-thioether chelates as caging groups have been elucidated.
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Affiliation(s)
- Daniele Belletto
- Department of Chemistry and Chemical Technologies, Università della Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende, CS, Italy.
| | - Fortuna Ponte
- Department of Chemistry and Chemical Technologies, Università della Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende, CS, Italy.
| | - Gloria Mazzone
- Department of Chemistry and Chemical Technologies, Università della Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende, CS, Italy.
| | - Emilia Sicilia
- Department of Chemistry and Chemical Technologies, Università della Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende, CS, Italy.
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8
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Barretta P, Scoditti S, Belletto D, Ponte F, Vigna V, Mazzone G, Sicilia E. Ruthenium complexes bearing nile red chromophore and one of its derivative: Theoretical evaluation of PDT-related properties. J Comput Chem 2024. [PMID: 38733370 DOI: 10.1002/jcc.27392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/25/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024]
Abstract
The outcomes of DFT-based calculations are here reported to assess the applicability of two synthesized polypyridyl Ru(II) complexes, bearing ethynyl nile red (NR) on a bpy ligand, and two analogues, bearing modified-NR, in photodynamic therapy. The absorption spectra, together with the non-radiative rate constants for the S1 - Tn intersystem crossing transitions, have been computed for this purpose. Calculations evidence that the structural modification on the chromophore destabilizes the HOMO of the complexes thus reducing the H-L gap and, consequently, red shifting the maximum absorption wavelength within the therapeutic window, up to 620 nm. Moreover, the favored ISC process from the bright state involves the triplet state closest in energy, which is also characterized by the highest SOC value and by the involvement of the whole bpy ligand bearing the chromophore in delocalising the unpaired electrons. These outcomes show that the photophysical behavior of the complexes is dominated by the chromophore.
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Affiliation(s)
- Pierraffaele Barretta
- Department of Chemistry and Chemical Technologies, Università della Calabria, Arcavacata di Rende (CS), Italy
| | - Stefano Scoditti
- Department of Chemistry and Chemical Technologies, Università della Calabria, Arcavacata di Rende (CS), Italy
| | - Daniele Belletto
- Department of Chemistry and Chemical Technologies, Università della Calabria, Arcavacata di Rende (CS), Italy
| | - Fortuna Ponte
- Department of Chemistry and Chemical Technologies, Università della Calabria, Arcavacata di Rende (CS), Italy
| | - Vincenzo Vigna
- Department of Chemistry and Chemical Technologies, Università della Calabria, Arcavacata di Rende (CS), Italy
| | - Gloria Mazzone
- Department of Chemistry and Chemical Technologies, Università della Calabria, Arcavacata di Rende (CS), Italy
| | - Emilia Sicilia
- Department of Chemistry and Chemical Technologies, Università della Calabria, Arcavacata di Rende (CS), Italy
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9
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Saridakis I, Riomet M, Belleza OJV, Coussanes G, Singer NK, Kastner N, Xiao Y, Smith E, Tona V, de la Torre A, Lopes EF, Sánchez-Murcia PA, González L, Sitte HH, Maulide N. PyrAtes: Modular Organic Salts with Large Stokes Shifts for Fluo-rescence Microscopy. Angew Chem Int Ed Engl 2024; 63:e202318127. [PMID: 38570814 DOI: 10.1002/anie.202318127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Indexed: 04/05/2024]
Abstract
The deployment of small-molecule fluorescent agents plays an ever-growing role in medicine and drug development. Herein, we complement the portfolio of powerful fluorophores, reporting the serendipitous discovery and development of a novel class with an imidazo[1,2-a]pyridinium triflate core, which we term PyrAtes. These fluorophores are synthesized in a single step from readily available materials (>60 examples) and display Stokes shifts as large as 240 nm, while also reaching NIR-I emissions at λmax as long as 720 nm. Computational studies allow the development of a platform for the prediction of λmax and λEm. Furthermore, we demonstrate the compatibility of these novel fluorophores with live cell imaging in HEK293 cells, suggesting PyrAtes as potent intracellular markers.
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Affiliation(s)
- Iakovos Saridakis
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
- Vienna Doctoral School in Chemistry (DoSChem), University of Vienna, Währinger Strasse 42, 1090, Vienna, Austria
| | - Margaux Riomet
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Oliver J V Belleza
- Centre of Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Schwarzspanierstraße 17A, 1090, Vienna, Austria
| | - Guilhem Coussanes
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Nadja K Singer
- Institute of Theoretical Chemistry, University of Vienna, Währinger Strasse 17, 1090, Vienna, Austria
- Vienna Doctoral School in Chemistry (DoSChem), University of Vienna, Währinger Strasse 42, 1090, Vienna, Austria
| | - Nina Kastner
- Centre of Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Schwarzspanierstraße 17A, 1090, Vienna, Austria
| | - Yi Xiao
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
- Vienna Doctoral School in Chemistry (DoSChem), University of Vienna, Währinger Strasse 42, 1090, Vienna, Austria
- CeMM Research Center for Molecular Medicine of the, Austrian Academy of Sciences, Lazarettgasse 14, 1090, Vienna, Austria
| | - Elliot Smith
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Veronica Tona
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Aurélien de la Torre
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Eric F Lopes
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Pedro A Sánchez-Murcia
- Institute of Theoretical Chemistry, University of Vienna, Währinger Strasse 17, 1090, Vienna, Austria
| | - Leticia González
- Institute of Theoretical Chemistry, University of Vienna, Währinger Strasse 17, 1090, Vienna, Austria
| | - Harald H Sitte
- Centre of Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Schwarzspanierstraße 17A, 1090, Vienna, Austria
- Hourani Center for Applied Scientific Research, Al-Ahliyya Amman University, 19328, Amman, Jordan
- Center for Addiction Research and Science - AddRess, Medical University Vienna, Währinger Strasse 13 A, 1090, Vienna, Austria
| | - Nuno Maulide
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
- CeMM Research Center for Molecular Medicine of the, Austrian Academy of Sciences, Lazarettgasse 14, 1090, Vienna, Austria
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10
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Chaussy L, Chilkuri VG, Humbel S, Nava P. Spectroscopy of End-On Copper(II) Superoxido Complexes: A Wave Function-Based Analysis. Inorg Chem 2024; 63:8038-8049. [PMID: 38659336 DOI: 10.1021/acs.inorgchem.3c04401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Wave function methods are employed to analyze the ground and low-lying excited states of bipyramid trigonal copper(II) superoxido complexes, up to their characteristic ligand to metal charge transfer band. Several multireference methods have been combined to provide new insights into the interpretation of their experimental absorption spectra. We show that the intraligand transition on the dioxygen leads to a dark state. Among the results, we shall highlight the finding of doubly excited states in the region of the d-d transitions and the subtle interplay between Cu(I) and Cu(II) in the ground and excited states. Some of these findings could be obtained only with multireference methods.
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Affiliation(s)
- Léo Chaussy
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille 13397, France
| | | | - Stéphane Humbel
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille 13397, France
| | - Paola Nava
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille 13397, France
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11
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Chagas JCV, Milanez BD, Oliveira VP, Pinheiro M, Ferrão LFA, Aquino AJA, Lischka H, Machado FBC. A multi-descriptor analysis of substituent effects on the structure and aromaticity of benzene derivatives: π-Conjugation versus charge effects. J Comput Chem 2024; 45:863-877. [PMID: 38153839 DOI: 10.1002/jcc.27296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 11/29/2023] [Accepted: 12/10/2023] [Indexed: 12/30/2023]
Abstract
This work provides a detailed multi-component analysis of aromaticity in monosubstituted (X = CH3, CH 2 - , CH 2 + , NH2, NH-, NH+, OH, O-, and O+) and para-homodisubstituted (X = CH3, CH2, NH2, NH, OH, and O) benzene derivatives. We investigate the effects of substituents using single-reference (B3LYP/DFT) and multireference (CASSCF/MRCI) methods, focusing on structural (HOMA), vibrational (AI(vib)), topological (ELFπ), electronic (MCI), magnetic (NICS), and stability (S0-T1 splitting) properties. The findings reveal that appropriate π-electron-donating and π-electron-accepting substituents with suitable size and symmetry can interact with the π-system of the ring, significantly influencing π-electron delocalization. While the charge factor has a minimal impact on π-electron delocalization, the presence of a pz orbital capable of interacting with the π-electron delocalization is the primary factor leading to a deviation from the typical aromaticity characteristics observed in benzene.
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Affiliation(s)
- Julio C V Chagas
- Department of Chemistry, Aeronautics Institute of Technology, São José dos Campos, São Paulo, Brazil
| | - Bruno D Milanez
- Department of Chemistry, Aeronautics Institute of Technology, São José dos Campos, São Paulo, Brazil
| | - Vytor P Oliveira
- Department of Chemistry, Aeronautics Institute of Technology, São José dos Campos, São Paulo, Brazil
| | - Max Pinheiro
- Department of Chemistry, Aeronautics Institute of Technology, São José dos Campos, São Paulo, Brazil
| | - Luiz F A Ferrão
- Department of Chemistry, Aeronautics Institute of Technology, São José dos Campos, São Paulo, Brazil
| | - Adelia J A Aquino
- Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas, USA
| | - Hans Lischka
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Francisco B C Machado
- Department of Chemistry, Aeronautics Institute of Technology, São José dos Campos, São Paulo, Brazil
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12
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Jelenfi DP, Tajti A, Szalay PG. Interpretation of molecular electron transport in ab initio many-electron framework incorporating zero-point nuclear motion effects. J Comput Chem 2024. [PMID: 38703360 DOI: 10.1002/jcc.27381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/22/2024] [Accepted: 04/22/2024] [Indexed: 05/06/2024]
Abstract
A computational methodology, founded on chemical concepts, is presented for interpreting the role of nuclear motion in the electron transport through single-molecule junctions (SMJ) using many-electron ab initio quantum chemical calculations. Within this approach the many-electron states of the system, computed at the SOS-ADC(2) level, are followed along the individual normal modes of the encapsulated molecules. The inspection of the changes in the partial charge distribution of the many-electron states allows the quantification of the electron transport and the estimation of transmission probabilities. This analysis improves the understanding of the relationship between internal motions and electron transport. Two SMJ model systems are studied for validation purposes, constructed from a conductor (BDA, benzene-1,4-diamine) and an insulator molecule (DABCO, 1,4-diazabicyclo[2.2.2]octane). The trends of the resulting transmission probabilities are in agreement with the experimental observations, demonstrating the capability of the approach to distinguish between conductor and insulator type systems, thereby offering a straightforward and cost-effective tool for such classifications via quantum chemical calculations.
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Affiliation(s)
- Dávid P Jelenfi
- Hevesy György PhD School of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
- Institute of Chemistry, Laboratory of Theoretical Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Attila Tajti
- Institute of Chemistry, Laboratory of Theoretical Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Péter G Szalay
- Institute of Chemistry, Laboratory of Theoretical Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
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13
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East NR, Naumann R, Förster C, Ramanan C, Diezemann G, Heinze K. Oxidative two-state photoreactivity of a manganese(IV) complex using near-infrared light. Nat Chem 2024; 16:827-834. [PMID: 38332331 DOI: 10.1038/s41557-024-01446-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 01/11/2024] [Indexed: 02/10/2024]
Abstract
Highly reducing or oxidizing photocatalysts are a fundamental challenge in photochemistry. Only a few transition metal complexes with Earth-abundant metal ions have so far advanced to excited state oxidants. All these photocatalysts require high-energy light for excitation, and their oxidizing power has not been fully exploited due to energy dissipation before reaching the photoactive state. Here we demonstrate that the complex [Mn(dgpy)2]4+, based on Earth-abundant manganese and the tridentate 2,6-diguanidylpyridine ligand (dgpy), evolves to a luminescent doublet ligand-to-metal charge transfer (2LMCT) excited state (1,435 nm, 0.86 eV) with a lifetime of 1.6 ns after excitation with low-energy near-infrared light. This 2LMCT state oxidizes naphthalene to its radical cation. Substrates with extremely high oxidation potentials up to 2.4 V enable the [Mn(dgpy)2]4+ photoreduction via a high-energy quartet 4LMCT excited state with a lifetime of 0.78 ps, proceeding via static quenching by the solvent. This process minimizes free energy losses and harnesses the full photooxidizing power, and thus allows oxidation of nitriles and benzene using Earth-abundant elements and low-energy light.
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Affiliation(s)
- Nathan R East
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Charusheela Ramanan
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Max-Planck-Institute for Polymer Research, Mainz, Germany
| | - Gregor Diezemann
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany.
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14
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Ribeiro RB, Varella MTDN. Excited state properties of an A-D-A non-fullerene electron acceptor: a LC-TD-DFTB study. Phys Chem Chem Phys 2024; 26:12993-13005. [PMID: 38639076 DOI: 10.1039/d3cp06166c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Understanding charge transfer processes is essential to estimate the performance of organic photovoltaic technologies. Although experimental production is on the rise, predictability strongly relies on theoretical modeling, which is limited to the size of semiconductors. As a computationally favorable approach, we benchmarked the long-range corrected (LC) time-dependent (TD) formulation of the semi-empirical density functional-based tight-binding method (DFTB) for three polycyclic aromatic hydrocarbons (PAHs) and studied the DTP-IC-4Ph molecule, a PAH-based non-fullerene electron acceptor (NFA) with an A-D-A backbone structure. After a thorough investigation into the long-range parameter (ω) tuning for naphthalene, anthracene and pyrene, the excitation energies, oscillator strengths and Natural Transition Orbitals (NTOs) were compared with the standard ωB97X-D/6-31G(d,p) level of theory and the ADC2/6-31G(d,p) multiconfigurational method. We estimated mobility-related properties of the NFA and considered 1000 thermally accessible configurations to qualitatively reproduce the experimental absorption profile and investigate the energetic disorder. Finally, we conducted a fragment-based analysis using the one-electron transition density matrix (1TDM) to determine the character of the excited states and investigate the effect of side chains on exciton formation. Our results are sensitive to the level of theory and highly dependent on the long-range parameter but suggest that the presence of alkyl chains promotes a higher average charge delocalization and allows for additional hopping mechanisms, favoring the charge transfer dynamics.
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Affiliation(s)
- R B Ribeiro
- Rua do Matão, 1371 - Butantã, São Paulo, Brazil, 05508-090.
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15
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Mandal S, Daniel C. Ultrafast Excited-State Nonadiabatic Dynamics in Pt(II) Donor-Bridge-Acceptor Assemblies: A Quantum Approach for Optical Control. J Phys Chem A 2024; 128:3126-3136. [PMID: 38619836 DOI: 10.1021/acs.jpca.4c00646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
The ultrafast nonadiabatic excited state dynamics of (PTZ-N-benzyl-acetylide) (trans-bis-trimethylphosphine) Pt(II) (acetylide-NDI-bis-methyl) 1, representative of a series of Pt(II) donor-bridge-acceptor assemblies experimentally studied by the Weinstein group, University of Sheffield, is investigated by means of wavepacket propagations based on the multiconfiguration time-dependent Hartree (MCTDH) method. On the basis of electronic structure data obtained at the time-dependent density functional theory (TD-DFT) level, the subpicosecond decay is simulated by solving an 11 electronic states multimode problem, up to 18 vibrational normal modes, including both spin-orbit coupling (SOC) and vibronic coupling. A careful analysis of the results, within the diabatic representation, provides the key features of the spin-vibronic mechanism at work in this complex, distinguishing between the spin-orbit and vibronically activated ultrafast processes within the excited states manifold. The knowledge of the key active normal modes that promote selectively the population of specific electronic excited states opens a route toward optical control by selectively exciting these modes in order to drive the associated nonadiabatic processes. Relevant simulations, over 2 ps, are proposed to assess the impact of these selective vibrational excitations on the branching ratio between the primary photoproducts, namely, bridge-acceptor charge-transfer (CT) and donor-acceptor charge-separated (CS) electronic states. Whereas the excitation of the localized acetylide bridge C≡C bond stretching does not modify drastically the population of the low-lying electronic states within the first two ps, vibrational excitation of the out-of-plane twisting motion of the N-benzyl group linked to the donor entity favors the population of the 1,3CS states at the expense of the lowest 1,3CT states. This quantum study opens the route to IR optical control experiments based on the specific alteration of vibrational normal modes that activate vibronic couplings between key electronic excited states. However, the presence of critical crossings along the PES channels associated with these normal modes and the role of concurrent SOC driven ultrafast transfers of population should not be underestimated.
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Affiliation(s)
- Souvik Mandal
- Laboratoire de Chimie Quantique, Institut de Chimie Strasbourg, UMR-7177 CNRS, Université de Strasbourg, 1 Rue Blaise Pascal BP 296/R8, F-67008 Strasbourg, France
| | - Chantal Daniel
- Laboratoire de Chimie Quantique, Institut de Chimie Strasbourg, UMR-7177 CNRS, Université de Strasbourg, 1 Rue Blaise Pascal BP 296/R8, F-67008 Strasbourg, France
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16
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Pazos A, Cruz CM, Cuerva JM, Rivilla I, Cossío FP, Freixa Z. Enantiopure [6]-Azairidahelicene by Dynamic Kinetic Resolution of a Configurationally Labile [4]-Helicene. Angew Chem Int Ed Engl 2024:e202406663. [PMID: 38655628 DOI: 10.1002/anie.202406663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 04/23/2024] [Accepted: 04/23/2024] [Indexed: 04/26/2024]
Abstract
A pair of enantiopure [6]-azairidahelicenes incorporating chirality at the metal center and on the helicenic ligand were synthesized by dynamic kinetic resolution (dkr) of a configurationally labile [4]-helicenic ligand (4-(2-pyridyl)-benzo[g]phenanthrene, L1H) using bis-cyclometalated chiral-at-metal only iridium(III) precursors as chiral inductors. The origin of the observed dkr is attributed to the different conformation and stability of diastereomeric reaction intermediates formed during the cyclometalation process. The isolated enantiomers exhibited circularly polarized phosphorescence (CPP), with |gphos| values of 1.8×10-3.
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Affiliation(s)
- Ariadna Pazos
- Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country (UPV/EHU), 20018, Donostia, Spain
| | - Carlos M Cruz
- Department of Organic Chemistry, Unidad de Excelencia de Química (UEQ), Faculty of Sciences, University of Granada, Avda. Fuente Nueva s/n, 18071, Granada, Spain
| | - Juan M Cuerva
- Department of Organic Chemistry, Unidad de Excelencia de Química (UEQ), Faculty of Sciences, University of Granada, Avda. Fuente Nueva s/n, 18071, Granada, Spain
| | - Ivan Rivilla
- IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
- Department of Organic Chemistry II, Faculty of Chemistry, University of the Basque Country (UPV/EHU), 20018, Donostia, Spain
- Donostia International Physics Center (DIPC), 20018, Donostia, Spain
| | - Fernando P Cossío
- Department of Organic Chemistry II, Faculty of Chemistry, University of the Basque Country (UPV/EHU), 20018, Donostia, Spain
- Donostia International Physics Center (DIPC), 20018, Donostia, Spain
| | - Zoraida Freixa
- Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country (UPV/EHU), 20018, Donostia, Spain
- IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
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17
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Madden E, Zwijnenburg MA. The effect of particle size on the optical and electronic properties of hydrogenated silicon nanoparticles. Phys Chem Chem Phys 2024; 26:11695-11707. [PMID: 38563473 DOI: 10.1039/d4cp00119b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
We use a combination of many-body perturbation theory and time-dependent density functional theory to study the optical and electronic properties of hydrogen terminated silicon nanoparticles. We predict that the lowest excited states of these silicon nanoparticles are excitonic in character and that the corresponding excitons are completely delocalised over the volume of the particle. The size of the excitons is predicted to increase proportionally with the particle size. Conversely, we predict that the fundamental gap, the optical gap, and the exciton binding energy increase with decreasing particle size. The exciton binding energy is predicted to counter-act the variation in the fundamental gap and hence to reduce the variation of the optical gap with particle size. The variation in the exciton binding energy itself is probably caused by a reduction in the dielectric screening with decreasing particle size. The intensity of the excited state corresponding to the optical gap and other low energy excitations are predicted to increase with decreasing particle size. We explain this increase in terms of the 'band structure' becoming smeared out in reciprocal space with decreasing particle size, increasing the 'overlap' between the occupied and unoccupied quasiparticle states and thus, the oscillator strength. Fourier transforms of the lowest excitons show that they inherit the periodicity of the frontier quasiparticle states. This, combined with the delocalisation of the exciton and the large exciton binding energy, means that the excitons in silicon nanoparticles combine aspects of Wannier-Mott, delocalisation and effect of periodicity of the underlying structure, and Frenkel, large exciton binding energy, excitons.
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Affiliation(s)
- Eimear Madden
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Martijn A Zwijnenburg
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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18
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Schulz T, Hédé S, Weingart O, Marian CM. Multiexcitonic and optically bright states in subunits of pentacene crystals: A hybrid DFT/MRCI and molecular mechanics study. J Chem Phys 2024; 160:144114. [PMID: 38597311 DOI: 10.1063/5.0203006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 03/22/2024] [Indexed: 04/11/2024] Open
Abstract
A hybrid quantum mechanics/molecular mechanics setup was used to model electronically excited pentacene in the crystal phase. Particularly interesting in the context of singlet fission (SF) is the energetic location of the antiferromagnetically coupled multiexcitonic singlet state, 1(TT), and the ferromagnetically coupled analog in relation to the optically bright singlet state. To provide photophysical properties of the accessible spin manifold, combined density functional theory and multi-reference configuration interaction calculations were performed on pentacene dimers and a trimer, electrostatically embedded in the crystal. The likelihood of a quintet intermediate in the SF process was estimated by computing singlet-quintet electron spin-spin couplings employing the Breit-Pauli Hamiltonian. The performance of the applied methods was assessed on the pentacene monomer. The character of the optically bright state and the energetic location of the 1(TT) state depend strongly on the relative orientation of the pentacene units. In the V-shaped dimers and in the trimer, the optically bright state is dominated by local and charge transfer (CT) excitations, with admixtures of doubly excited configurations. The CT excitations gain weight upon geometry relaxation, thus supporting a CT-mediated SF mechanism as the primary step of the SF process. For the slip-stacked dimer, the energetic order of the bright and the 1(TT) states swaps upon geometry relaxation, indicating strong nonadiabatic coupling close to the Franck-Condon region-a prerequisite for a coherent SF process. The multiexcitonic singlet, triplet, and quintet states are energetically too far apart and their spin-spin couplings are too small to bring about a noteworthy multiplicity mixing.
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Affiliation(s)
- Timo Schulz
- Institute of Theoretical and Computational Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Simon Hédé
- Institute of Theoretical and Computational Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Oliver Weingart
- Institute of Theoretical and Computational Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christel M Marian
- Institute of Theoretical and Computational Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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19
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Franz J, Oelschlegel M, Zobel JP, Hua SA, Borter JH, Schmid L, Morselli G, Wenger OS, Schwarzer D, Meyer F, González L. Bifurcation of Excited-State Population Leads to Anti-Kasha Luminescence in a Disulfide-Decorated Organometallic Rhenium Photosensitizer. J Am Chem Soc 2024; 146. [PMID: 38598687 PMCID: PMC11046484 DOI: 10.1021/jacs.4c00548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/07/2024] [Accepted: 03/12/2024] [Indexed: 04/12/2024]
Abstract
We report a rhenium diimine photosensitizer equipped with a peripheral disulfide unit on one of the bipyridine ligands, [Re(CO)3(bpy)(S-Sbpy4,4)]+ (1+, bpy = 2,2'-bipyridine, S-Sbpy4,4 = [1,2]dithiino[3,4-c:6,5-c']dipyridine), showing anti-Kasha luminescence. Steady-state and ultrafast time-resolved spectroscopies complemented by nonadiabatic dynamics simulations are used to disclose its excited-state dynamics. The calculations show that after intersystem crossing the complex evolves to two different triplet minima: a (S-Sbpy4,4)-ligand-centered excited state (3LC) lying at lower energy and a metal-to-(bpy)-ligand charge transfer (3MLCT) state at higher energy, with relative yields of 90% and 10%, respectively. The 3LC state involves local excitation of the disulfide group into the antibonding σ* orbital, leading to significant elongation of the S-S bond. Intriguingly, it is the higher-lying 3MLCT state, which is assigned to display luminescence with a lifetime of 270 ns: a signature of anti-Kasha behavior. This assignment is consistent with an energy barrier ≥ 0.6 eV or negligible electronic coupling, preventing reaction toward the 3LC state after the population is trapped in the 3MLCT state. This study represents a striking example on how elusive excited-state dynamics of transition-metal photosensitizers can be deciphered by synergistic experiments and state-of-the-art calculations. Disulfide functionalization lays the foundation of a new design strategy toward harnessing excess energy in a system for possible bimolecular electron or energy transfer reactivity.
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Affiliation(s)
- Julia Franz
- Institute
of Theoretical Chemistry, University of
Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Manuel Oelschlegel
- Institute
of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, D-37077 Göttingen, Germany
| | - J. Patrick Zobel
- Institute
of Theoretical Chemistry, University of
Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Shao-An Hua
- Institute
of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Jan-Hendrik Borter
- Department
of Dynamics at Surfaces, Max-Planck-Institute
for Multidisciplinary Sciences, Am Faßberg 11, D-37077 Göttingen, Germany
| | - Lucius Schmid
- Department
of Chemistry, University of Basel, St.-Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Giacomo Morselli
- Department
of Chemistry, University of Basel, St.-Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St.-Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Dirk Schwarzer
- Department
of Dynamics at Surfaces, Max-Planck-Institute
for Multidisciplinary Sciences, Am Faßberg 11, D-37077 Göttingen, Germany
| | - Franc Meyer
- Institute
of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, D-37077 Göttingen, Germany
- International
Center for Advanced Studies of Energy Conversion (ICASEC), D-37077 Göttingen, Germany
| | - Leticia González
- Institute
of Theoretical Chemistry, University of
Vienna, Währinger Straße 17, A-1090 Vienna, Austria
- Vienna Research
Platform for Accelerating Photoreaction Discovery, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
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20
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Cho HH, Congrave DG, Gillett AJ, Montanaro S, Francis HE, Riesgo-Gonzalez V, Ye J, Chowdury R, Zeng W, Etherington MK, Royakkers J, Millington O, Bond AD, Plasser F, Frost JM, Grey CP, Rao A, Friend RH, Greenham NC, Bronstein H. Suppression of Dexter transfer by covalent encapsulation for efficient matrix-free narrowband deep blue hyperfluorescent OLEDs. NATURE MATERIALS 2024; 23:519-526. [PMID: 38480865 PMCID: PMC10990937 DOI: 10.1038/s41563-024-01812-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 01/18/2024] [Indexed: 03/21/2024]
Abstract
Hyperfluorescence shows great promise for the next generation of commercially feasible blue organic light-emitting diodes, for which eliminating the Dexter transfer to terminal emitter triplet states is key to efficiency and stability. Current devices rely on high-gap matrices to prevent Dexter transfer, which unfortunately leads to overly complex devices from a fabrication standpoint. Here we introduce a molecular design where ultranarrowband blue emitters are covalently encapsulated by insulating alkylene straps. Organic light-emitting diodes with simple emissive layers consisting of pristine thermally activated delayed fluorescence hosts doped with encapsulated terminal emitters exhibit negligible external quantum efficiency drops compared with non-doped devices, enabling a maximum external quantum efficiency of 21.5%. To explain the high efficiency in the absence of high-gap matrices, we turn to transient absorption spectroscopy. It is directly observed that Dexter transfer from a pristine thermally activated delayed fluorescence sensitizer host can be substantially reduced by an encapsulated terminal emitter, opening the door to highly efficient 'matrix-free' blue hyperfluorescence.
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Affiliation(s)
- Hwan-Hee Cho
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Daniel G Congrave
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
| | | | - Stephanie Montanaro
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Haydn E Francis
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot, UK
| | - Víctor Riesgo-Gonzalez
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot, UK
| | - Junzhi Ye
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - Weixuan Zeng
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Marc K Etherington
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Ellison Place, Newcastle upon Tyne, UK
| | - Jeroen Royakkers
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Oliver Millington
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Andrew D Bond
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Felix Plasser
- Department of Chemistry, Loughborough University, Loughborough, UK
| | | | - Clare P Grey
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot, UK
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - Neil C Greenham
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| | - Hugo Bronstein
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
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21
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Avagliano D, Skreta M, Arellano-Rubach S, Aspuru-Guzik A. DELFI: a computer oracle for recommending density functionals for excited states calculations. Chem Sci 2024; 15:4489-4503. [PMID: 38516092 PMCID: PMC10952086 DOI: 10.1039/d3sc06440a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/05/2024] [Indexed: 03/23/2024] Open
Abstract
Density functional theory (DFT) is the workhorse of computational quantum chemistry. One of its main limitations is that choosing the right functional is a non-trivial task left for human experts. The choice is particularly hard for excited state calculations when using its time-dependent formulation (TD-DFT). This is due to the approximations of the method, but also because the photophysical properties of a molecule are defined by a manifold of states that all need to be properly described. This includes not only the relative energy of the states, but also capturing the correct character, order, and intensity of the transitions. In this work, we developed a neural network to recommend functionals to be used on molecules for TD-DFT calculations, by simultaneously considering all these properties for a manifold of states. This was possible by developing a scoring system to define the accuracy of an excited state's calculation against a higher-accuracy reference. The scoring system is generalizable to any level of theory; we here applied it to evaluate the performance of common functionals of different rungs against a higher accuracy method on a large set of organic molecules. The results are collected in a database that we released and made open, providing four million data points to the community for future applications. The scoring system assigns a value between zero and one hundred to each functional for each molecule, transforming the complicated task of learning photophysical properties into a simpler regression task. We used the dataset to train a graph attention neural network to predict the scores for unseen molecules. We call this oracle DELFI (Data-driven EvaLuation of Functionals by Inference), which can be used to quickly screen and predict the ranking of functionals to calculate the optical properties of organic molecules. We validated DELFI in two in silico experiments: choosing a common functional for a series of spiropyran-merocyanine isomers and a unique functional to screen a large dataset of over 50 000 organic photovoltaic molecules, for which an extensive benchmark would be unfeasible. A corresponding web application allows DELFI to be easily run and the results to be analyzed, alleviating the hurdle of choosing the right functional for TD-DFT calculations.
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Affiliation(s)
- Davide Avagliano
- Department of Chemistry, University of Toronto 80 St. George Street Toronto ON M5S 3H6 Canada
- Department of Computer Science, University of Toronto 40 St. George Street Toronto ON M5S 2E4 Canada
| | - Marta Skreta
- Department of Computer Science, University of Toronto 40 St. George Street Toronto ON M5S 2E4 Canada
- Vector Institute for Artificial Intelligence 661 University Ave. Suite 710 ON M5G 1M1 Toronto Canada
| | | | - Alán Aspuru-Guzik
- Department of Chemistry, University of Toronto 80 St. George Street Toronto ON M5S 3H6 Canada
- Department of Computer Science, University of Toronto 40 St. George Street Toronto ON M5S 2E4 Canada
- Vector Institute for Artificial Intelligence 661 University Ave. Suite 710 ON M5G 1M1 Toronto Canada
- Department of Materials Science & Engineering, University of Toronto 184 College St Toronto M5S 3E4 Canada
- Department of Chemical Engineering & Applied Chemistry, University of Toronto 200 College St ON M5S 3E5 Toronto Canada
- Lebovic Fellow, Canadian Institute for Advanced Research (CIFAR) 66118 University Ave. M5G 1M1 Toronto Canada
- Acceleration Consortium 80 St George St M5S 3H6 Toronto Canada
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22
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Ding B, Bhosale M, Bennett TLR, Heeney M, Plasser F, Esser B, Glöcklhofer F. Reducing undesired solubility of squarephaneic tetraimide for use as an organic battery electrode material. Faraday Discuss 2024; 250:129-144. [PMID: 37965707 PMCID: PMC10926975 DOI: 10.1039/d3fd00145h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 08/17/2023] [Indexed: 11/16/2023]
Abstract
Locally aromatic alkyl-N-substituted squarephaneic tetraimide (SqTI) conjugated macrocycles are four-electron reducible, owing to global aromaticity and presumed global Baird aromaticity of the dianion and tetraanion states, respectively. However, their good solubility inhibits their application as a battery electrode material. By applying sidechain removal as a strategy to reduce SqTI solubility, we report the development of its unsubstituted derivative SqTI-H, which was obtained directly from squarephaneic tetraanhydride by facile treatment with hexamethyldisilazane and MeOH. Compared to alkyl-N-substituted SqTI-Rs, SqTI-H exhibited further improved thermal stability and low neutral state solubility in most common organic solvents, owing to computationally demonstrated hydrogen-bonding capabilities emanating from each imide position on SqTI-H. Reversible solid state electrochemical reduction of SqTI-H to the globally aromatic dianion state was also observed at -1.25 V vs. Fc/Fc+, which could be further reduced in two stages. Preliminary testing of SqTI-H in composite electrodes for lithium-organic half cells uncovered imperfect cycling performance, which may be explained by persistent solubility of reduced states, necessitating further optimisation of electrode fabrication procedures to attain maximum performance.
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Affiliation(s)
- Bowen Ding
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub (White City Campus), 80 Wood Lane Shepherd's Bush, London W12 0BZ, UK.
| | - Manik Bhosale
- Institute of Organic Chemistry II and Advanced Materials, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | - Troy L R Bennett
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub (White City Campus), 80 Wood Lane Shepherd's Bush, London W12 0BZ, UK.
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub (White City Campus), 80 Wood Lane Shepherd's Bush, London W12 0BZ, UK.
- Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Felix Plasser
- Department of Chemistry, Loughborough University, Loughborough LE11 3TU, UK
| | - Birgit Esser
- Institute of Organic Chemistry II and Advanced Materials, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | - Florian Glöcklhofer
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub (White City Campus), 80 Wood Lane Shepherd's Bush, London W12 0BZ, UK.
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060 Vienna, Austria.
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23
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Ju CW, Shen Y, French EJ, Yi J, Bi H, Tian A, Lin Z. Accurate Electronic and Optical Properties of Organic Doublet Radicals Using Machine Learned Range-Separated Functionals. J Phys Chem A 2024. [PMID: 38382058 DOI: 10.1021/acs.jpca.3c07437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Luminescent organic semiconducting doublet-spin radicals are unique and emergent optical materials because their fluorescent quantum yields (Φfl) are not compromised by the spin-flipping intersystem crossing (ISC) into a dark high-spin state. The multiconfigurational nature of these radicals challenges their electronic structure calculations in the framework of single-reference density functional theory (DFT) and introduces room for method improvement. In the present study, we extended our earlier development of ML-ωPBE [J. Phys. Chem. Lett., 2021, 12, 9516-9524], a range-separated hybrid (RSH) exchange-correlation (XC) functional constructed using the stacked ensemble machine learning (SEML) algorithm, from closed-shell organic semiconducting molecules to doublet-spin organic semiconducting radicals. We assessed its performance for a new test set of 64 doublet-spin radicals from five categories while placing all previously compiled 3926 closed-shell molecules in the new training set. Interestingly, ML-ωPBE agrees with the nonempirical OT-ωPBE functional regarding the prediction of the molecule-dependent range-separation parameter (ω), with a small mean absolute error (MAE) of 0.0197 a0-1, but saves the computational cost by 2.46 orders of magnitude. This result demonstrates an outstanding domain adaptation capacity of ML-ωPBE for diverse organic semiconducting species. To further assess the predictive power of ML-ωPBE in experimental observables, we also applied it to evaluate absorption and fluorescence energies (Eabs and Efl) using linear-response time-dependent DFT (TDDFT), and we compared its behavior with nine popular XC functionals. For most radicals, ML-ωPBE reproduces experimental measurements of Eabs and Efl with small MAEs of 0.299 and 0.254 eV, only marginally different from those of OT-ωPBE. Our work illustrates a successful extension of the SEML framework from closed-shell molecules to doublet-spin radicals and will open the venue for calculating optical properties for organic semiconductors using single-reference TDDFT.
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Affiliation(s)
- Cheng-Wei Ju
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Yili Shen
- Manning College of Information and Computer Sciences, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Ethan J French
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Jun Yi
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Chemistry, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Hongshan Bi
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Aaron Tian
- Manning College of Information and Computer Sciences, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Zhou Lin
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
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24
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Streater DH, Kennehan ER, Wang D, Fiankor C, Chen L, Yang C, Li B, Liu D, Ibrahim F, Hermans I, Kohlstedt KL, Luo L, Zhang J, Huang J. Control over Charge Separation by Imine Structural Isomerization in Covalent Organic Frameworks with Implications on CO 2 Photoreduction. J Am Chem Soc 2024; 146:4489-4499. [PMID: 38327095 DOI: 10.1021/jacs.3c10627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Two-dimensional covalent organic frameworks (COFs) are an emerging class of photocatalytic materials for solar energy conversion. In this work, we report a pair of structurally isomeric COFs with reversed imine bond directions, which leads to drastic differences in their physical properties, photophysical behaviors, and photocatalytic CO2 reduction performance after incorporating a Re(bpy)(CO)3Cl molecular catalyst through bipyridyl units on the COF backbone (Re-COF). Using the combination of ultrafast spectroscopy and theory, we attributed these differences to the polarized nature of the imine bond that imparts a preferential direction to intramolecular charge transfer (ICT) upon photoexcitation, where the bipyridyl unit acts as an electron acceptor in the forward imine case (f-COF) and as an electron donor in the reverse imine case (r-COF). These interactions ultimately lead the Re-f-COF isomer to function as an efficient CO2 reduction photocatalyst, while the Re-r-COF isomer shows minimal photocatalytic activity. These findings not only reveal the essential role linker chemistry plays in COF photophysical and photocatalytic properties but also offer a unique opportunity to design photosensitizers that can selectively direct charges.
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Affiliation(s)
- Daniel H Streater
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Eric R Kennehan
- Magnitude Instruments, 200 Innovation Boulevard Ste. 224, State College, Pennsylvania 16803, United States
| | - Denan Wang
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Christian Fiankor
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Liangji Chen
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Chongqing Yang
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Bo Li
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Daohua Liu
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Faysal Ibrahim
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ive Hermans
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kevin L Kohlstedt
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Long Luo
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Jian Zhang
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jier Huang
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
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25
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Bozzi ÍAO, Machado LA, Diogo EBT, Delolo FG, Barros LOF, Graça GAP, Araujo MH, Martins FT, Pedrosa LF, da Luz LC, Moraes ES, Rodembusch FS, Guimarães JSF, Oliveira AG, Röttger SH, Werz DB, Souza CP, Fantuzzi F, Han J, Marder TB, Braunschweig H, da Silva Júnior EN. Electrochemical Diselenation of BODIPY Fluorophores for Bioimaging Applications and Sensitization of 1 O 2. Chemistry 2024; 30:e202303883. [PMID: 38085637 DOI: 10.1002/chem.202303883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Indexed: 01/19/2024]
Abstract
We report a rapid, efficient, and scope-extensive approach for the late-stage electrochemical diselenation of BODIPYs. Photophysical analyses reveal red-shifted absorption - corroborated by TD-DFT and DLPNO-STEOM-CCSD computations - and color-tunable emission with large Stokes shifts in the selenium-containing derivatives compared to their precursors. In addition, due to the presence of the heavy Se atoms, competitive ISC generates triplet states which sensitize 1 O2 and display phosphorescence in PMMA films at RT and in a frozen glass matrix at 77 K. Importantly, the selenium-containing BODIPYs demonstrate the ability to selectively stain lipid droplets, exhibiting distinct fluorescence in both green and red channels. This work highlights the potential of electrochemistry as an efficient method for synthesizing unique emission-tunable fluorophores with broad-ranging applications in bioimaging and related fields.
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Affiliation(s)
- Ícaro A O Bozzi
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Luana A Machado
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Emilay B T Diogo
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Fábio G Delolo
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Luiza O F Barros
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Gabriela A P Graça
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Maria H Araujo
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Felipe T Martins
- Instituto de Química, Universidade Federal de Goiás, Goiânia, 74690-900, Brazil
| | - Leandro F Pedrosa
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal Fluminense, Volta Redonda, RJ, 27213-145, Brazil
| | - Lilian C da Luz
- Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970, RS, Brazil
| | - Emmanuel S Moraes
- Universidade Estadual de Campinas (Unicamp), Cidade Universitária, 13083970 -, Campinas, SP, Brazil
| | - Fabiano S Rodembusch
- Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970, RS, Brazil
| | - João S F Guimarães
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - André G Oliveira
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sebastian H Röttger
- DFG Cluster of Excellence livMatS @FIT and Albert-Ludwigs-Universität Freiburg, Institute of Organic Chemistry, Albertstraße 21, 79104, Freiburg (Breisgau), Germany
| | - Daniel B Werz
- DFG Cluster of Excellence livMatS @FIT and Albert-Ludwigs-Universität Freiburg, Institute of Organic Chemistry, Albertstraße 21, 79104, Freiburg (Breisgau), Germany
| | - Cauê P Souza
- School of Chemistry and Forensic Science, University of Kent, Park Wood Rd, Canterbury, CT2 7NH, United Kingdom
| | - Felipe Fantuzzi
- School of Chemistry and Forensic Science, University of Kent, Park Wood Rd, Canterbury, CT2 7NH, United Kingdom
| | - Jianhua Han
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Todd B Marder
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Eufrânio N da Silva Júnior
- Instituto de Ciências Exatas, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
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26
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Giuso V, Gourlaouen C, Delporte-Pébay M, Groizard T, Vanthuyne N, Crassous J, Daniel C, Mauro M. Chiroptical activity of benzannulated N-heterocyclic carbene rhenium(I) tricarbonyl halide complexes: towards efficient circularly polarized luminescence emitters. Phys Chem Chem Phys 2024; 26:4855-4869. [PMID: 37994151 DOI: 10.1039/d3cp04300b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
The design of enantiomerically pure circularly polarized luminescent (CPL) emitters would enormously benefit from the accurate and in-depth interpretation of the chiroptical properties by means of jointly (chiroptical) photophysical measurements and state-of-the-art theoretical investigation. Herein, computed and experimental (chiro-)optical properties of a series of eight enantiopure phosphorescent rhenium(I) tricarbonyl complexes are systematically compared in terms of electronic circular dichroism (ECD) and CPL. The compounds have general formula fac-[ReX(CO)3(N^CNHC)], where N^CNHC is a pyridyl benzannulated N-heterocyclic carbene deriving from a (substituted) 2-(pyridin-2-yl)imidazo[1,5-a]pyridin-2-ium proligand and X = Cl, Br and I, and display structured red phosphorescence with long-lived (τ = 7.0-19.1 μs) excited-state lifetime and dissymmetry factors |gLum| up to 4 × 10-3. The mixing of the character of the lowest-lying emitting triplet excited state is finely modulated between ligand centred (3LC), metal-to-ligand charge transfer (3MLCT) and halogen-to-ligand charge transfer (3XLCT) by the nature of the ancillary halogen and the chromophoric N^CNHC ligand. The study unravels the effect exerted by the nature of the excited state onto the ECD and CPL activity and will help to pave the way to construct efficient CPL emitters by chemical design.
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Affiliation(s)
- Valerio Giuso
- Université de Strasbourg, CNRS Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 23 rue du Loess, 67034 Strasbourg, France.
| | - Christophe Gourlaouen
- Laboratoire de Chimie Quantique Université de Strasbourg CNRS UMR7177 Institut Le Bel 4 Rue Blaise Pascal, 67000 Strasbourg, France.
| | | | - Thomas Groizard
- Laboratoire de Chimie Quantique Université de Strasbourg CNRS UMR7177 Institut Le Bel 4 Rue Blaise Pascal, 67000 Strasbourg, France.
| | - Nicolas Vanthuyne
- Aix Marseille University, CNRS Centrale Marseille, iSm2, 13284 Marseille, France
| | - Jeanne Crassous
- Université de Rennes, CNRS, ISCR - UMR 6226, 35000 Rennes, France.
| | - Chantal Daniel
- Laboratoire de Chimie Quantique Université de Strasbourg CNRS UMR7177 Institut Le Bel 4 Rue Blaise Pascal, 67000 Strasbourg, France.
| | - Matteo Mauro
- Université de Strasbourg, CNRS Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 23 rue du Loess, 67034 Strasbourg, France.
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27
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Karak P, Moitra T, Banerjee A, Ruud K, Chakrabarti S. Accidental triplet harvesting in donor-acceptor dyads with low spin-orbit coupling. Phys Chem Chem Phys 2024; 26:5344-5355. [PMID: 38268441 DOI: 10.1039/d3cp04904c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Abstract
We present an accidental mechanism for efficient intersystem crossing (ISC) between singlet and triplet states with low spin-orbit coupling (SOC) in molecules having donor-acceptor (D-A) moieties separated by a Sigma bond. Our study shows that SOC between the lowest singlet excited state and the higher-lying triplet states, together with nuclear motion-driven coupling of this triplet state with lower-lying triplet states during the free rotation about a Sigma bond, is one of the possible ways to achieve the experimentally observed ISC rate for a class of D-A type photoredox catalysts. This mechanism is found to be the dominant contributor to the ISC process with the corresponding rate reaching a maximum at a dihedral angle in the range of 72°-78° between the D-A moieties of 10-(naphthalen-1-yl)-3,7-diphenyl-10H-phenoxazine and other molecules included in the study. We have further demonstrated that the same mechanism is operative in a specific spirobis[anthracene]dione molecule, where the D and A moieties are interlocked near to the optimal dihedral angle, indicating the plausible effectiveness of the proposed mechanism. The present finding is expected to have implications in strategies for the synthesis of new generations of triplet-harvesting organic molecules.
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Affiliation(s)
- Pijush Karak
- Department of Chemistry, University of Calcutta, 92 A.P.C Road, Kolkata - 700009, West Bengal, India.
| | - Torsha Moitra
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Tromsø - The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Ambar Banerjee
- Department of Physics and Astronomy, X-ray Photon Science, Uppsala University, Ångströmlaboratoriet, Lägerhyddsvägen 1, 75120, Uppsala, Sweden.
| | - Kenneth Ruud
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Tromsø - The Arctic University of Norway, 9037 Tromsø, Norway.
- Norwegian Defence Research Establishment, P.O.Box 25, 2027 Kjeller, Norway
| | - Swapan Chakrabarti
- Department of Chemistry, University of Calcutta, 92 A.P.C Road, Kolkata - 700009, West Bengal, India.
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28
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Jankowska J, Sobolewski AL. Photo-oxidation of methanol in complexes with pyrido[2,3- b]pyrazine: a nonadiabatic molecular dynamics study. Phys Chem Chem Phys 2024; 26:5296-5302. [PMID: 38265828 DOI: 10.1039/d3cp04148d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Excited-state Proton-Coupled Electron Transfer (PCET) constitutes a key step in the photo-oxidation of small, electron-rich systems possessing acidic hydrogen atoms, such as water or alcohols, which can play a vital role in green hydrogen production. In this contribution, we employ ab initio quantum-chemical methods and on-the-fly nonadiabatic molecular dynamics simulations to study the mechanism and the photodynamics of PCET in 1 : 1 pyrido[2,3-b]pyrazine complexes with methanol. We find the process to be ultrafast and efficient when the intramolecular hydrogen bond is formed with one of the β-positioned nitrogen atoms. The complex exhibiting a hydrogen bond with an isolated nitrogen site, on the contrary, shows much lower reactivity. We explain this effect with the stabilization of the reactive ππ* charge-transfer electronic state in the former case.
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Affiliation(s)
- Joanna Jankowska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, Warsaw 02-093, Poland.
| | - Andrzej L Sobolewski
- Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
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29
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Unger F, Lepple D, Asbach M, Craciunescu L, Zeiser C, Kandolf AF, Fišer Z, Hagara J, Hagenlocher J, Hiller S, Haug S, Deutsch M, Grüninger P, Novák J, Bettinger HF, Broch K, Engels B, Schreiber F. Optical Absorption Properties in Pentacene/Tetracene Solid Solutions. J Phys Chem A 2024; 128:747-760. [PMID: 38232326 DOI: 10.1021/acs.jpca.3c06737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Modifying the optical and electronic properties of crystalline organic thin films is of great interest for improving the performance of modern organic semiconductor devices. Therein, the statistical mixing of molecules to form a solid solution provides an opportunity to fine-tune optical and electronic properties. Unfortunately, the diversity of intermolecular interactions renders mixed organic crystals highly complex, and a holistic picture is still lacking. Here, we report a study of the optical absorption properties in solid solutions of pentacene and tetracene, two prototypical organic semiconductors. In the mixtures, the optical properties can be continuously modified by statistical mixing at the molecular level. Comparison with time-dependent density functional theory calculations on occupationally disordered clusters unravels the electronic origin of the low energy optical transitions. The disorder partially relaxes the selection rules, leading to additional optical transitions that manifest as optical broadening. Furthermore, the contribution of diabatic charge-transfer states is modified in the mixtures, reducing the observed splitting in the 0-0 vibronic transition. Additional comparisons with other blended systems generalize our results and indicate that changes in the polarizability of the molecular environment in organic thin-film blends induce shifts in the absorption spectrum.
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Affiliation(s)
- Frederik Unger
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Daniel Lepple
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Maximilian Asbach
- Julius-Maximilian University Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Luca Craciunescu
- Julius-Maximilian University Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS Scotland, U.K
| | - Clemens Zeiser
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Andreas F Kandolf
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
- Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Zbyněk Fišer
- Department of Condensed Matter Physics (UFKL), Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Jakub Hagara
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Jan Hagenlocher
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Stefan Hiller
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Sara Haug
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Marian Deutsch
- Julius-Maximilian University Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Peter Grüninger
- Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Jiří Novák
- Department of Condensed Matter Physics (UFKL), Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Holger F Bettinger
- Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Katharina Broch
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Bernd Engels
- Julius-Maximilian University Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Frank Schreiber
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
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30
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Herbert JM. Visualizing and characterizing excited states from time-dependent density functional theory. Phys Chem Chem Phys 2024; 26:3755-3794. [PMID: 38226636 DOI: 10.1039/d3cp04226j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Time-dependent density functional theory (TD-DFT) is the most widely-used electronic structure method for excited states, due to a favorable combination of low cost and semi-quantitative accuracy in many contexts, even if there are well recognized limitations. This Perspective describes various ways in which excited states from TD-DFT calculations can be visualized and analyzed, both qualitatively and quantitatively. This includes not just orbitals and densities but also well-defined statistical measures of electron-hole separation and of Frenkel-type exciton delocalization. Emphasis is placed on mathematical connections between methods that have often been discussed separately. Particular attention is paid to charge-transfer diagnostics, which provide indicators of when TD-DFT may not be trustworthy due to its categorical failure to describe long-range electron transfer. Measures of exciton size and charge separation that are directly connected to the underlying transition density are recommended over more ad hoc metrics for quantifying charge-transfer character.
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Affiliation(s)
- John M Herbert
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA.
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31
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Mandal P, Panda AN. Contrasting the excited state properties of different conformers of trans- and cis-2,2'-bipyridine oligomers in the gas phase. Phys Chem Chem Phys 2024; 26:2646-2656. [PMID: 38174437 DOI: 10.1039/d3cp05313j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
In this article, we present conformation-dependent photophysical and excited state properties of trans- and cis- BPY oligomers. Oligomers up to tetramers for three conformers, namely, o-, m-, and p-, are constructed and optimized at the B3LYP-D3/def2-SVPD level. The photophysical and excited state properties are interpreted in terms of UV and CD spectra at the RI-ADC(2)/def2-TZVPD level. The UV spectra of oligomers of the m-conformer show high-intensity and red-shifted UV bands compared to o- and p-oligomers. The CD spectra of p-oligomers show intense CD bands compared to o- and p-oligomers in the case of trans-structures. In contrast, oligomers of each conformer of cis-structures show high-intensity CD bands. The excited states of (BPY)2 and (BPY)4 are also characterized by analysis of one-electron transition density matrix considering three descriptors: ωCT, dexc, and PRNTO. The ωCT values of dimers are in the range of 0.06-0.32, which indicates the excited states are mainly LE states, whereas, for (BPY)4, the ωCT values range from 0.17 to 0.53, indicating the possibility of partial CT in the excited states. These observations are also explained using the NTOs and e-h correlation plots.
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Affiliation(s)
- Palak Mandal
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, India.
| | - Aditya N Panda
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, India.
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Craciunescu L, Asbach M, Wirsing S, Hammer S, Unger F, Broch K, Schreiber F, Witte G, Dreuw A, Tegeder P, Fantuzzi F, Engels B. Cluster-Based Approach Utilizing Optimally Tuned TD-DFT to Calculate Absorption Spectra of Organic Semiconductor Thin Films. J Chem Theory Comput 2023; 19:9369-9387. [PMID: 38073092 DOI: 10.1021/acs.jctc.3c01107] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
The photophysics of organic semiconductor (OSC) thin films or crystals has garnered significant attention in recent years since a comprehensive theoretical understanding of the various processes occurring upon photoexcitation is crucial for assessing the efficiency of OSC materials. To date, research in this area has relied on methods using Frenkel-Holstein Hamiltonians, calculations of the GW-Bethe-Salpeter equation with periodic boundaries, or cluster-based approaches using quantum chemical methods, with each of the three approaches having distinct advantages and disadvantages. In this work, we introduce an optimally tuned, range-separated time-dependent density functional theory approach to accurately reproduce the total and polarization-resolved absorption spectra of pentacene, tetracene, and perylene thin films, all representative OSC materials. Our approach achieves excellent agreement with experimental data (mostly ≤0.1 eV) when combined with the utilization of clusters comprising multiple monomers and a standard polarizable continuum model to simulate the thin-film environment. Our protocol therefore addresses a major drawback of cluster-based approaches and makes them attractive tools for OSC investigations. Its key advantages include its independence from external, system-specific fitting parameters and its straightforward application with well-known quantum chemical program codes. It demonstrates how chemical intuition can help to reduce computational cost and still arrive at chemically meaningful and almost quantitative results.
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Affiliation(s)
- Luca Craciunescu
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Str. 42, 97074 Würzburg, Germany
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS Scotland, U.K
| | - Maximilian Asbach
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Str. 42, 97074 Würzburg, Germany
| | - Sara Wirsing
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Str. 42, 97074 Würzburg, Germany
| | - Sebastian Hammer
- Experimentelle Physik VI, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Center for the Physics of Materials, Department of Physics and Department of Chemistry, McGill University, 801 Sherbrooke St. W, Montreal, H3A 2K6 Québec, Canada
| | - Frederik Unger
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Katharina Broch
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Frank Schreiber
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Gregor Witte
- Molekulare Festkörperphysik, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Andreas Dreuw
- Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Universität Heidelberg, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Petra Tegeder
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Felipe Fantuzzi
- School of Chemistry and Forensic Science, University of Kent, Park Wood Rd, CT2 7NH Canterbury, U.K
| | - Bernd Engels
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Str. 42, 97074 Würzburg, Germany
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33
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Cole HD, Vali A, Roque JA, Shi G, Kaur G, Hodges RO, Francés-Monerris A, Alberto ME, Cameron CG, McFarland SA. Ru(II) Phenanthroline-Based Oligothienyl Complexes as Phototherapy Agents. Inorg Chem 2023; 62:21181-21200. [PMID: 38079387 PMCID: PMC10754219 DOI: 10.1021/acs.inorgchem.3c03216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2023]
Abstract
Ru(II) polypyridyl complexes have gained widespread attention as photosensitizers for photodynamic therapy (PDT). Herein, we systematically investigate a series of the type [Ru(phen)2(IP-nT)]2+, featuring 1,10-phenanthroline (phen) coligands and imidazo[4,5-f][1,10]phenanthroline ligands tethered to n = 0-4 thiophene rings (IP-nT). The complexes were characterized and investigated for their electrochemical, spectroscopic, and (photo)biological properties. The electrochemical oxidation of the nT unit shifted by -350 mV as n = 1 → 4 (+920 mV for Ru-1T, +570 mV for Ru-4T); nT reductions were observed in complexes Ru-3T (-2530 mV) and Ru-4T (-2300 mV). Singlet oxygen quantum yields ranged from 0.53 to 0.88, with Ru-3T and Ru-4T being equally efficient (∼0.88). Time-resolved absorption spectra of Ru-0T-1T were dominated by metal-to-ligand charge-transfer (3MLCT) states (τTA = 0.40-0.85 μs), but long-lived intraligand charge-transfer (3ILCT) states were observed in Ru-2T-4T (τTA = 25-148 μs). The 3ILCT energies of Ru-3T and Ru-4T were computed to be 1.6 and 1.4 eV, respectively. The phototherapeutic efficacy against melanoma cells (SK-MEL-28) under broad-band visible light (400-700 nm) increases as n = 0 → 4: Ru-0T was inactive up to 300 μM, Ru-1T-2T were moderately active (EC50 ∼ 600 nM, PI = 200), and Ru-3T (EC50 = 57 nM, PI > 1100) and Ru-4T (EC50 = 740 pM, PI = 114,000) were the most phototoxic. The activity diminishes with longer wavelengths of light and is completely suppressed for all complexes except Ru-3T and Ru-4T in hypoxia. Ru-4T is the more potent and robust PS in 1% O2 over seven biological replicates (avg EC50 = 1.3 μM, avg PI = 985). Ru-3T exhibited hypoxic activity in five of seven replicates, underscoring the need for biological replicates in compound evaluation. Singlet oxygen sensitization is likely responsible for phototoxic effects of the compounds in normoxia, but the presence of redox-active excited states may facilitate additional photoactive pathways for complexes with three or more thienyl groups. The 3ILCT state with its extended lifetime (30-40× longer than the 3MLCT state for Ru-3T and Ru-4T) implicates its predominant role in photocytotoxicity.
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Affiliation(s)
- Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - Abbas Vali
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - John A. Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402 USA
| | - Ge Shi
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - Gurleen Kaur
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - Rachel O. Hodges
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402 USA
| | | | - Marta E. Alberto
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende, 87036 Italy
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
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34
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Potempa K, Deresz KA, Jankowska J, Jarzembska KN, Krówczyński A, Mikhailov A, Schaniel D, Kamiński R. Interrelations between Linkage Isomers of an Efficient Square-planar Nickel(II) Nitrite Photoswitch in the Solid State. Chemistry 2023; 29:e202302629. [PMID: 37723126 DOI: 10.1002/chem.202302629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 09/11/2023] [Accepted: 09/18/2023] [Indexed: 09/20/2023]
Abstract
An efficient nitrite nickel(II) photoswitch, with the 1-phenyl-2-hydroxyimino-3-[(2'-dimethylamino)ethyl]imino-1-propanone moiety used as the ancillary ligand, is reported. In the ground-state ('dark') crystal structure, the studied compound exists predominantly as the nitro-(η1 -N(O)2 ) isomer, however, traces of the exo- and endo-nitrito-(η1 -ONO) forms are detected both at 100 K (4-5 % each) and under ambient conditions (~9 % each). When excited with the 405-530 nm LED light, the nitro-to-nitrito isomerization takes place. The total conversion exceeds 90 %. The exo-nitrito linkage isomer constitutes the dominant photo-generated form, whereas the relative population of both nitrito species depends on temperature. The reaction is fully reversible and reproducible. The photo-products are stable up to 200 K. The system constitutes a good model case for the reaction mechanism studies. Thus, experimental and theoretical investigations on the photo-isomerism were conducted and are presented in detail. Eventually, the nitro→exo-nitrito→endo-nitrito reaction pathway is proposed.
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Affiliation(s)
- Kinga Potempa
- Department of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Krystyna A Deresz
- Department of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Joanna Jankowska
- Department of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
| | - Katarzyna N Jarzembska
- Department of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Adam Krówczyński
- Department of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | | | | | - Radosław Kamiński
- Department of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
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35
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Medina Rivero S, Alonso-Navarro MJ, Tonnelé C, Marín-Beloqui JM, Suárez-Blas F, Clarke TM, Kang S, Oh J, Ramos MM, Kim D, Casanova D, Segura JL, Casado J. V-Shaped Tröger Oligothiophenes Boost Triplet Formation by CT Mediation and Symmetry Breaking. J Am Chem Soc 2023; 145:27295-27306. [PMID: 38060544 PMCID: PMC10839832 DOI: 10.1021/jacs.3c06916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/08/2023] [Accepted: 11/17/2023] [Indexed: 12/21/2023]
Abstract
A new family of molecules obtained by coupling Tröger's base unit with dicyanovinylene-terminated oligothiophenes of different lengths has been synthesized and characterized by steady-state stationary and transient time-resolved spectroscopies. Quantum chemical calculations allow us to interpret and recognize the properties of the stationary excited states as well as the time-dependent mechanisms of singlet-to-triplet coupling. The presence of the diazocine unit in Tröger's base derivatives is key to efficiently producing singlet-to-triplet intersystem crossing mediated by the role of the nitrogen atoms and of the almost orthogonal disposition of the two thiophene arms. Spin-orbit coupling-mediated interstate intersystem crossing (ISC) is activated by a symmetry-breaking process in the first singlet excited state with partial charge transfer character. This mechanism is a characteristic of these molecular triads since the independent dicyanovinylene-oligothiophene branches do not display appreciable ISC. These results show how Tröger's base coupling of organic chromophores can be used to improve the ISC efficiency and tune their photophysics.
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Affiliation(s)
- Samara Medina Rivero
- Department
of Physical Chemistry, Faculty of Science, University of Málaga, 29071 Málaga, Spain
- Department
of Physics and Astronomy, University of
Sheffield, Sheffield S3 7RH, United Kingdom
| | - Matías J. Alonso-Navarro
- Organic
Chemistry Department, Faculty of Chemistry, Complutense University of Madrid, 28040 Madrid, Spain
- Chemical
and Environmental Technology Department, Rey Juan Carlos University, 28933 Madrid, Spain
| | - Claire Tonnelé
- Donostia
International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain
- Ikerbasque
Foundation for Science, 48009 Bilbao, Euskadi, Spain
| | - Jose M. Marín-Beloqui
- Department
of Physical Chemistry, Faculty of Science, University of Málaga, 29071 Málaga, Spain
| | - Fátima Suárez-Blas
- Organic
Chemistry Department, Faculty of Chemistry, Complutense University of Madrid, 28040 Madrid, Spain
- Chemical
and Environmental Technology Department, Rey Juan Carlos University, 28933 Madrid, Spain
| | - Tracey M. Clarke
- Department
of Chemistry, University College London, London WC1H 0AJ, U.K.
| | - Seongsoo Kang
- Department
of Chemistry, Yonsei University, Seoul 03722, Korea
| | - Juwon Oh
- Department
of Chemistry, Soonchunhyang University, Asan 31538, Korea
| | - M. Mar Ramos
- Chemical
and Environmental Technology Department, Rey Juan Carlos University, 28933 Madrid, Spain
| | - Dongho Kim
- Department
of Chemistry, Yonsei University, Seoul 03722, Korea
- Division
of Energy Materials, Pohang University of
Science and Technology (POSTECH), Pohang 37673, Korea
| | - David Casanova
- Donostia
International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain
- Ikerbasque
Foundation for Science, 48009 Bilbao, Euskadi, Spain
| | - José L. Segura
- Organic
Chemistry Department, Faculty of Chemistry, Complutense University of Madrid, 28040 Madrid, Spain
| | - Juan Casado
- Department
of Physical Chemistry, Faculty of Science, University of Málaga, 29071 Málaga, Spain
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36
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do Casal MT, Veys K, Bousquet MHE, Escudero D, Jacquemin D. First-Principles Calculations of Excited-State Decay Rate Constants in Organic Fluorophores. J Phys Chem A 2023; 127:10033-10053. [PMID: 37988002 DOI: 10.1021/acs.jpca.3c06191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
In this Perspective, we discuss recent advances made to evaluate from first-principles the excited-state decay rate constants of organic fluorophores, focusing on the so-called static strategy. In this strategy, one essentially takes advantage of Fermi's golden rule (FGR) to evaluate rate constants at key points of the potential energy surfaces, a procedure that can be refined in a variety of ways. In this way, the radiative rate constant can be straightforwardly obtained by integrating the fluorescence line shape, itself determined from vibronic calculations. Likewise, FGR allows for a consistent calculation of the internal conversion (related to the non-adiabatic couplings) in the weak-coupling regime and intersystem crossing rates, therefore giving access to estimates of the emission yields when no complex photophysical phenomenon is at play. Beyond outlining the underlying theories, we summarize here the results of benchmarks performed for various types of rates, highlighting that both the quality of the vibronic calculations and the accuracy of the relative energies are crucial to reaching semiquantitative estimates. Finally, we illustrate the successes and challenges in determining the fluorescence quantum yields using a series of organic fluorophores.
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Affiliation(s)
- Mariana T do Casal
- Department of Chemistry, Physical Chemistry and Quantum Chemistry Division, KU Leuven, 3001 Leuven, Belgium
| | - Koen Veys
- Department of Chemistry, Physical Chemistry and Quantum Chemistry Division, KU Leuven, 3001 Leuven, Belgium
| | | | - Daniel Escudero
- Department of Chemistry, Physical Chemistry and Quantum Chemistry Division, KU Leuven, 3001 Leuven, Belgium
| | - Denis Jacquemin
- Nantes Université, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
- Institut Universitaire de France (IUF), FR-75005 Paris, France
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37
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Borges I, Guimarães RMPO, Monteiro-de-Castro G, Rosa NMP, Nieman R, Lischka H, Aquino AJA. A comprehensive analysis of charge transfer effects on donor-pyrene (bridge)-acceptor systems using different substituents. J Comput Chem 2023; 44:2424-2436. [PMID: 37638684 DOI: 10.1002/jcc.27208] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 07/27/2023] [Accepted: 08/02/2023] [Indexed: 08/29/2023]
Abstract
The alternant polycyclic aromatic hydrocarbon pyrene has photophysical properties that can be tuned with different donor and acceptor substituents. Recently, a D (donor)-Pyrene (bridge)-A (acceptor) system, DPA, with the electron donor N,N-dimethylaniline (DMA), and the electron acceptor trifluoromethylphenyl (TFM), was investigated by means of time-resolved spectroscopic measurements (J. Phys. Chem. Lett. 2021, 12, 2226-2231). DPA shows great promise for potential applications in organic electronic devices. In this work, we used the ab initio second-order algebraic diagrammatic construction method ADC(2) to investigate the excited-state properties of a series of analogous DPA systems, including the originally synthesized DPAs. The additionally investigated substituents were amino, fluorine, and methoxy as donors and nitrile and nitro groups as acceptors. The focus of this work was on characterizing the lowest excited singlet states regarding charge transfer (CT) and local excitation (LE) characters. For the DMA-pyrene-TFM system, the ADC(2) calculations show two initial electronic states relevant for interpreting the photodynamics. The bright S1 state is locally excited within the pyrene moiety, and an S2 state is localized ~0.5 eV above S1 and characterized as a donor to pyrene CT state. HOMO and LUMO energies were employed to assess the efficiency of the DPA compounds for organic photovoltaics (OPVs). HOMO-LUMO and optical gaps were used to estimate power conversion and light-harvesting efficiencies for practical applications in organic solar cells. Considering the systems using smaller D/A substituents, compounds with the strong acceptor NO2 substituent group show enhanced CT and promising properties for use in OPVs. Some of the other compounds with small substituents are also found to be competitive in this regard.
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Affiliation(s)
- Itamar Borges
- Departamento de Química, Instituto Militar de Engenharia (IME), Rio de Janeiro, Brazil
| | | | | | - Nathália M P Rosa
- Departamento de Química, Instituto Militar de Engenharia (IME), Rio de Janeiro, Brazil
| | - Reed Nieman
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Hans Lischka
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Adelia J A Aquino
- Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas, USA
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38
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Abou Taka A, Herbert JM, McCaslin LM. Ground-State Orbital Analysis Predicts S 1 Charge Transfer in Donor-Acceptor Materials. J Phys Chem Lett 2023:11063-11068. [PMID: 38048425 DOI: 10.1021/acs.jpclett.3c02787] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
Donor-acceptor (D-A) materials can exhibit a wide range of unique photophysical properties with applications in next-generation optoelectronics. Electronic structure calculations of D-A dimers are often employed to predict the properties of D-A materials. One of the most important D-A dimer quantities is the degree of charge transfer (DCT) in the S1 state, which correlates with properties such as fluorescence lifetimes and intersystem crossing rates in D-A materials. While predictive metrics of the S1 DCT generally require an excited-state quantum chemistry calculation, presented here is a novel metric that predicts S1 DCT solely with ground-state orbital analysis. This metric quantifies the similarity of the orbitals between a dimer complex and its monomer components. A linear relationship is found between this similarity metric and the S1 DCT, calculated using a data set of 31 D-A dimers. Best practices for integrating this novel orbital structure-function relationship into high-throughput screening methods are discussed.
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Affiliation(s)
- Ali Abou Taka
- Sandia National Laboratories, Livermore, California 94550, United States
| | - John M Herbert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Laura M McCaslin
- Sandia National Laboratories, Livermore, California 94550, United States
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39
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Šrut A, Krewald V. Vibrational Coherences of the Photoinduced Mixed-Valent Creutz-Taube Ion Revealed by Excited State Dynamics. J Phys Chem A 2023; 127:9911-9920. [PMID: 37883652 DOI: 10.1021/acs.jpca.3c04415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
A recent study of photoinduced mixed-valency in the one-electron reduced form (μ-pz)[RuII(NH3)5]24+ of the Creutz-Taube ion used transient absorption spectroscopy with vis-NIR broadband detection to uncover a mixed-valent excited state with a typical intervalence charge transfer band and a nanosecond lifetime [Pieslinger et al. Angew. Chem., Int. Ed. 2022, 61, e202211747]. Herein, we use excited state dynamics simulations with implicit solvation to elucidate the electronic and vibrational evolution in the first 10 ps after the optical excitation. A manifold of excited states with weak interaction between the metal centers is populated already at time zero due to the breakdown of the Condon approximation and dominates the population of electronic states at short time scales (<0.5 ps). A long-lived vibrational wave packet mostly confined to oscillations of the metal center-bridge distances is observed. The oscillations are traced to the electronic structure properties of states with weak metal-metal coupling. The long-lived mixed-valent excited state of the Creutz-Taube ion analogue is formed vibrationally cold and has a more compact geometry. While experimentally, intersystem crossing and vibrational relaxation were deduced to be completed within 1 ps, our analysis indicates that both processes might persist at longer times.
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Affiliation(s)
- Adam Šrut
- Department of Chemistry, Theoretical Chemistry, TU Darmstadt, Peter-Grünberg-Straße 4, 64287 Darmstadt, Germany
| | - Vera Krewald
- Department of Chemistry, Theoretical Chemistry, TU Darmstadt, Peter-Grünberg-Straße 4, 64287 Darmstadt, Germany
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40
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Clark JA, Kusy D, Vakuliuk O, Krzeszewski M, Kochanowski KJ, Koszarna B, O'Mari O, Jacquemin D, Gryko DT, Vullev VI. The magic of biaryl linkers: the electronic coupling through them defines the propensity for excited-state symmetry breaking in quadrupolar acceptor-donor-acceptor fluorophores. Chem Sci 2023; 14:13537-13550. [PMID: 38033901 PMCID: PMC10685337 DOI: 10.1039/d3sc03812b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 11/04/2023] [Indexed: 12/02/2023] Open
Abstract
Charge transfer (CT) is key for molecular photonics, governing the optical properties of chromophores comprising electron-rich and electron-deficient components. In photoexcited dyes with an acceptor-donor-acceptor or donor-acceptor-donor architecture, CT breaks their quadrupolar symmetry and yields dipolar structures manifesting pronounced solvatochromism. Herein, we explore the effects of electronic coupling through biaryl linkers on the excited-state symmetry breaking of such hybrid dyes composed of an electron-rich core, i.e., 1,4-dihydropyrrolo[3,2-b]pyrrole (DHPP), and pyrene substituents that can act as electron acceptors. Experimental and theoretical studies reveal that strengthening the donor-acceptor electronic coupling decreases the CT rates and the propensity for symmetry breaking. We ascribe this unexpected result to effects of electronic coupling on the CT thermodynamics, which in its turn affects the CT kinetics. In cases of intermediate electronic coupling, the pyrene-DHPP conjugates produce fluorescence spectra, spreading over the whole visible range, that in addition to the broad CT emission, show bands from the radiative deactivation of the locally excited states of the donor and the acceptors. Because the radiative deactivation of the low-lying CT states is distinctly slow, fluorescence from upper locally excited states emerge leading to the observed anti-Kasha behaviour. As a result, these dyes exhibit white fluorescence. In addition to demonstrating the multifaceted nature of the effects of electronic coupling on CT dynamics, these chromophores can act as broad-band light sources with practical importance for imaging and photonics.
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Affiliation(s)
- John A Clark
- Department of Bioengineering, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
| | - Damian Kusy
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44-52 01-224 Warsaw Poland
| | - Olena Vakuliuk
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44-52 01-224 Warsaw Poland
| | - Maciej Krzeszewski
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44-52 01-224 Warsaw Poland
| | - Krzysztof J Kochanowski
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44-52 01-224 Warsaw Poland
| | - Beata Koszarna
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44-52 01-224 Warsaw Poland
| | - Omar O'Mari
- Department of Bioengineering, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
| | - Denis Jacquemin
- Nantes Université, CNRS CEISAM UMR 6230 F-44000 Nantes France
- Institut Universitaire de France (IUF) F-75005 Paris France
| | - Daniel T Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44-52 01-224 Warsaw Poland
| | - Valentine I Vullev
- Department of Bioengineering, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
- Department of Chemistry, University of California Riverside CA 92521 USA
- Department of Biochemistry, University of California Riverside CA 92521 USA
- Materials Science and Engineering Program, University of California Riverside CA 92521 USA
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Jordan R, Maisuls I, Nair SS, Dietzek-Ivanšić B, Strassert CA, Klein A. Enhanced luminescence properties through heavy ancillary ligands in [Pt(C^N^C)(L)] complexes, L = AsPh 3 and SbPh 3. Dalton Trans 2023. [PMID: 38013458 DOI: 10.1039/d3dt03225f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
In the frame of our research aiming to develop efficient triplet-emitting materials, we are exploring the concept of introducing additional heavy atoms into cyclometalated transition metal complexes to enhance intersystem-crossing (ISC) and thus triplet emission through increased spin-orbit coupling (SOC). In an in-depth proof-of-principle study we investigated the double cyclometalated Pt(II) complexes [Pt(C^N^C)(PnPh3)] (HC^N^CH = 2,6-diphenyl-pyridine (H2dpp) or dibenzoacridine (H2dba); Pn = pnictogen atoms P, As, Sb, or Bi) through a combined experimental and theoretical approach. The derivatives containing Pn = P, As, and Sb were synthesised and characterised comprehensively using single crystal X-ray diffraction (scXRD), UV-vis absorption and emission spectroscopy, transient absorption (TA) spectroscopy and cyclic voltammetry (CV). Across the series P < As < Sb, a red-shift is observed concerning absorption and emission maxima as well as optical and electrochemical HOMO-LUMO gaps. Increased photoluminescence quantum yields ΦL and radiative rates kr from mixed metal-to-ligand charge transfer (MLCT)/ligand centred (LC) triplet states are observed for the heavier homologues. Transient absorption spectroscopy showed processes in the ps range that were assigned to the population of the T1 state by ISC. The heavy PnPh3 ancillary ligands are found to enhance the emission efficiency due to both higher Pt-Pn bond strength and stronger SOC related to increased MLCT character of the excited states. The experimental findings are mirrored in hybrid (TD-)DFT calculations. This allowed for extrapolation to the rather elusive Bi derivatives, which were synthetically not accessible. This shortcoming is attributed to the transmetalation of phenyl groups from BiPh3 to Pt, as supported by experimental NMR/MS as well as DFT studies.
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Affiliation(s)
- Rose Jordan
- University of Cologne, Faculty for Mathematics and Natural Sciences, Department of Chemistry, Institute for Inorganic Chemistry, Greinstrasse 6, D-50939 Köln, Germany.
| | - Iván Maisuls
- Universität Münster, Institut für Anorganische und Analytische Chemie, CiMIC, CeNTech, Heisenbergstraße 11, D-48149 Münster, Germany.
| | - Shruthi S Nair
- Friedrich Schiller University Jena, Institute for Physical Chemistry (IPC), Helmholtzweg 4, 07743 Jena, Germany.
- Leibniz Institute for Photonic Technologies Jena (IPHT), Research Department Functional Interfaces, Albert-Einstein-Str. 9, 07745 Jena, Germany.
| | - Benjamin Dietzek-Ivanšić
- Friedrich Schiller University Jena, Institute for Physical Chemistry (IPC), Helmholtzweg 4, 07743 Jena, Germany.
- Leibniz Institute for Photonic Technologies Jena (IPHT), Research Department Functional Interfaces, Albert-Einstein-Str. 9, 07745 Jena, Germany.
| | - Cristian A Strassert
- Universität Münster, Institut für Anorganische und Analytische Chemie, CiMIC, CeNTech, Heisenbergstraße 11, D-48149 Münster, Germany.
| | - Axel Klein
- University of Cologne, Faculty for Mathematics and Natural Sciences, Department of Chemistry, Institute for Inorganic Chemistry, Greinstrasse 6, D-50939 Köln, Germany.
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do Monte S, Spada RFK, Alves RLR, Belcher L, Shepard R, Lischka H, Plasser F. Quantification of the Ionic Character of Multiconfigurational Wave Functions: The Qat Diagnostic. J Phys Chem A 2023; 127:9842-9852. [PMID: 37851528 PMCID: PMC10683019 DOI: 10.1021/acs.jpca.3c05559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/28/2023] [Indexed: 10/20/2023]
Abstract
The complete active space self-consistent field (CASSCF) method is a cornerstone in modern excited-state quantum chemistry providing the starting point for most common multireference computations. However, CASSCF, when used with a minimal active space, can produce significant errors (>2 eV) even for the excitation energies of simple hydrocarbons if the states of interest possess ionic character. After illustrating this problem in some detail, we present a diagnostic for ionic character, denoted as Q at, that is readily computed from the transition density. A set of 11 molecules is considered to study errors in vertical excitation energies. State-averaged CASSCF obtains a mean absolute error (MAE) of 0.87 eV for the 34 singlet states considered. We highlight a strong correlation between the obtained errors and the Q at diagnostic, illustrating its power to predict problematic cases. Conversely, using multireference configuration interaction with single and double excitations and Pople's size extensivity correction (MR-CISD+P), excellent results are obtained with an MAE of 0.11 eV. Furthermore, correlations with the Q at diagnostic disappear. In summary, we hope that the presented diagnostic will facilitate reliable and user-friendly multireference computations on conjugated organic molecules.
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Affiliation(s)
- Silmar
A. do Monte
- Departamento
de Química, CCEN, Universidade Federal
da Paraíba, 58051-900 João Pessoa, Brazil
| | - Rene F. K. Spada
- Departamento
de Física, Instituto Tecnológico
de Aeronáutica, 12.228-900 São José dos Campos, São Paulo, Brazil
| | - Rodolpho L. R. Alves
- Departamento
de Química, CCEN, Universidade Federal
da Paraíba, 58051-900 João Pessoa, Brazil
| | - Lachlan Belcher
- Departamento
de Física, Instituto Tecnológico
de Aeronáutica, 12.228-900 São José dos Campos, São Paulo, Brazil
| | - Ron Shepard
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, Lemont, Illinois 60439, United States
| | - Hans Lischka
- Department
of Chemistry and Biochemistry, Texas Tech
University, Lubbock, Texas 79409-1061, United States
| | - Felix Plasser
- Department
of Chemistry, Loughborough University, Loughborough LE11 3TU, U.K.
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43
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Ferrão LFA, Pontes MAP, Fernandes GFS, Bettanin F, Aquino AJA, Lischka H, Nachtigallova D, Machado FBC. Stability and Reactivity of the Phenalene and Olympicene Isomers. J Phys Chem A 2023; 127:9430-9441. [PMID: 37920974 DOI: 10.1021/acs.jpca.3c04331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
The phenalene (triangulene) and olympicene molecules belong to the polycyclic aromatic hydrocarbon class, which have attracted substantial technological interest due to their unique electronic properties. Electronic structure calculations serve as a valuable tool in investigating the stability and reactivity of these molecular systems. In the present work, the multireference calculations, namely, the complete active space second-order perturbation theory and multireference averaged quadratic coupled cluster (MR-AQCC), were employed to study the reactivity and stability of phenalene and olympicene isomers, as well as their modified structures where the sp3-carbon at the borders were removed. The harmonic oscillator model of aromaticity (HOMA) and the nucleus-independent chemical shift as geometric and magnetic indexes calculated with density functional theory were utilized to assess the aromaticity of the studied molecules. These indexes were compared with properties such as the excitation energy and natural orbitals occupation. The reactivity analyzed using the HOMA index combined with MR-AQCC revealed the radical character of certain structures as well as the weakening of their aromaticity. Moreover, the results suggest that the removal of sp3-carbon atoms and the addition of hydrogen atoms did not alter the π network and the excitation energies of the phenalene molecules.
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Affiliation(s)
- Luiz F A Ferrão
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Marcelo A P Pontes
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Gabriel F S Fernandes
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Fernanda Bettanin
- Escola de Artes, Ciências e Humanidades (EACH) - Universidade de São Paulo (USP), São Paulo 03828-000, SP, Brazil
| | - Adélia J A Aquino
- Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Hans Lischka
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, United States
| | - Dana Nachtigallova
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610 Prague 6, Czech Republic
- IT4Innovations, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, 70800 Ostrava-Poruba, Czech Republic
| | - Francisco B C Machado
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
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44
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Giuso V, Yang J, Forté J, Dossmann H, Daniel C, Gourlaouen C, Mauro M, Bertrand B. Binuclear Biphenyl Organogold(III) Complexes: Synthesis, Photophysical and Theoretical Investigation, and Anticancer Activity. Chempluschem 2023; 88:e202300303. [PMID: 37610058 DOI: 10.1002/cplu.202300303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 08/24/2023]
Abstract
A series of four binuclear complexes of general formula [(C^C)Au(Cl)(L^L)(Cl)Au(C^C)], where C^C is 4,4'-diterbutylbiphenyl and L^L is either a bridging diphosphine or 4,4'-bipyridine, are synthetized with 52 to 72 % yield and structurally characterized by X-ray diffraction. The use of the chelating 1,2-diphenylphosphinoethane ligand in a 1 : 2 (P^P):Au stoichiometry leads to the near quantitative formation of a gold double-complex salt of general formula [(C^C)Au(P^P)][(C^C^)AuCl2 ]. The compounds display long-lived yellow-green phosphorescence with λem in the range of 525 to 585 nm in the solid state with photoluminescence quantum yields (PLQY) up to 10 %. These AuIII complexes are tested for their antiproliferative activity against lung adenocarcinoma cells A549 and results show that compounds 2 and 5 are the most promising candidates. The digold salt 5 shows anticancer activity between 66 and 200 nM on the tested cancer cell lines, whereas derivative 2 displays concentration values required to reduce by 50 % the cell viability (IC50 ) between 7 and 11 μM. Reactivity studies of compound 5 reveal that the [(C^C)Au(P^P)]+ cation is stable in the presence of relevant biomolecules including glutathione suggesting a structural mechanism of action.
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Affiliation(s)
- Valerio Giuso
- Institut de Physique et Chimie des Matériaux de Strasbourg UMR 7504, Université de Strasbourg & CNRS, 23 rue du Loess, 67034, Strasbourg, France
| | - Jeannine Yang
- Institut Parisien de Chimie Moléculaire UMR 8232, Sorbonne Université, 4 Place Jussieu, 75005, Paris, France
| | - Jérémy Forté
- Institut Parisien de Chimie Moléculaire UMR 8232, Sorbonne Université, 4 Place Jussieu, 75005, Paris, France
| | - Héloïse Dossmann
- Institut Parisien de Chimie Moléculaire UMR 8232, Sorbonne Université, 4 Place Jussieu, 75005, Paris, France
| | - Chantal Daniel
- Institut de Chimie de Strasbourg, UMR 7177, Laboratoire de Chimie Quantique, Université de Strasbourg & CNRS, 4 rue Blaise Pascal, 67081, Strasbourg, France
| | - Christophe Gourlaouen
- Institut de Chimie de Strasbourg, UMR 7177, Laboratoire de Chimie Quantique, Université de Strasbourg & CNRS, 4 rue Blaise Pascal, 67081, Strasbourg, France
| | - Matteo Mauro
- Institut de Physique et Chimie des Matériaux de Strasbourg UMR 7504, Université de Strasbourg & CNRS, 23 rue du Loess, 67034, Strasbourg, France
| | - Benoît Bertrand
- Institut Parisien de Chimie Moléculaire UMR 8232, Sorbonne Université, 4 Place Jussieu, 75005, Paris, France
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Gutierrez Suburu ME, Blanke M, Hepp A, Maus O, Schwab D, Doltsinis NL, Zeier WG, Giese M, Voskuhl J, Strassert CA. Pt(II) Complexes with Tetradentate C^N*N^C Luminophores: From Supramolecular Interactions to Temperature-Sensing Materials with Memory and Optical Readouts. Molecules 2023; 28:7353. [PMID: 37959770 PMCID: PMC10649584 DOI: 10.3390/molecules28217353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/10/2023] [Accepted: 10/17/2023] [Indexed: 11/15/2023] Open
Abstract
A series of four regioisomeric Pt(II) complexes (PtLa-n and PtLb-n) bearing tetradentate luminophores as dianionic ligands were synthesized. Hence, both classes of cyclometallating chelators were decorated with three n-hexyl (n = 6) or n-dodecyl (n = 12) chains. The new compounds were unambiguously characterized by means of multiple NMR spectroscopies and mass spectrometry. Steady-state and time-resolved photoluminescence spectroscopy as well quantum chemical calculations show that the effect of the regioisomerism on the emission colour and on the deactivation rate constants can be correlated with the participation of the Pt atom on the excited state. The thermal properties of the complexes were studied by DSC, POM and temperature-dependent steady-state photoluminescence spectroscopy. Three of the four complexes (PtLa-12, PtLb-6 and PtLb-12) present an intriguing thermochromism resulting from the responsive metal-metal interactions involving adjacent monomeric units. Each material has different transition temperatures and memory capabilities, which can be tuned at the intermolecular level. Hence, dipole-dipole interactions between the luminophores and disruption of the crystalline packing by the alkyl groups are responsible for the final properties of the resulting materials.
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Affiliation(s)
- Matias E. Gutierrez Suburu
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
- Center of Nanotechnology (CeNTech), Center for Soft Nanosciences (SoN), Cells in Motion Interfaculty Cluster (CiMIC), Universität Münster, Heisenbergstraße 11, D-48149 Munster, Germany
| | - Meik Blanke
- Center for Nanointegration Duisburg-Essen (CENIDE), Faculty of Chemistry (Organic Chemistry), University of Duisburg-Essen, Universitätsstraße 7, D-45141 Essen, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
| | - Oliver Maus
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
| | - Dominik Schwab
- Center for Multiscale Theory and Computation, Institut für Festkörpertheorie, Universität Münster, Wilhelm-Klemm-Straße 10, D-48149 Münster, Germany
| | - Nikos L. Doltsinis
- Center for Multiscale Theory and Computation, Institut für Festkörpertheorie, Universität Münster, Wilhelm-Klemm-Straße 10, D-48149 Münster, Germany
| | - Wolfgang G. Zeier
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
| | - Michael Giese
- Center for Nanointegration Duisburg-Essen (CENIDE), Faculty of Chemistry (Organic Chemistry), University of Duisburg-Essen, Universitätsstraße 7, D-45141 Essen, Germany
| | - Jens Voskuhl
- Center for Nanointegration Duisburg-Essen (CENIDE), Faculty of Chemistry (Organic Chemistry), University of Duisburg-Essen, Universitätsstraße 7, D-45141 Essen, Germany
| | - Cristian A. Strassert
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, D-48149 Münster, Germany
- Center of Nanotechnology (CeNTech), Center for Soft Nanosciences (SoN), Cells in Motion Interfaculty Cluster (CiMIC), Universität Münster, Heisenbergstraße 11, D-48149 Munster, Germany
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46
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Abou Taka A, Reynolds JE, Cole-Filipiak NC, Shivanna M, Yu CJ, Feng P, Allendorf MD, Ramasesha K, Stavila V, McCaslin LM. Comparing the structures and photophysical properties of two charge transfer co-crystals. Phys Chem Chem Phys 2023; 25:27065-27074. [PMID: 37792449 DOI: 10.1039/d3cp03720g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Organic co-crystals have emerged as a promising class of semiconductors for next-generation optoelectronic devices due to their unique photophysical properties. This paper presents a joint experimental-theoretical study comparing the crystal structure, spectroscopy, and electronic structure of two charge transfer co-crystals. Reported herein is a novel co-crystal Npe:TCNQ, formed from 4-(1-naphthylvinyl)pyridine (Npe) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) via molecular self-assembly. This work also presents a revised study of the co-crystal composed of Npe and 1,2,4,5-tetracyanobenzene (TCNB) molecules, Npe:TCNB, herein reported with a higher-symmetry (monoclinic) crystal structure than previously published. Npe:TCNB and Npe:TCNQ dimer clusters are used as theoretical model systems for the co-crystals; the geometries of the dimers are compared to geometries of the extended solids, which are computed with periodic boundary conditions density functional theory. UV-Vis absorption spectra of the dimers are computed with time-dependent density functional theory and compared to experimental UV-Vis diffuse reflectance spectra. Both Npe:TCNB and Npe:TCNQ are found to exhibit neutral character in the S0 state and ionic character in the S1 state. The high degree of charge transfer in the S1 state of both Npe:TCNB and Npe:TCNQ is rationalized by analyzing the changes in orbital localization associated with the S1 transitions.
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Affiliation(s)
- Ali Abou Taka
- Sandia National Laboratories, Livermore, California 94550, USA.
| | | | | | - Mohana Shivanna
- Sandia National Laboratories, Livermore, California 94550, USA.
| | - Christine J Yu
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA
| | - Patrick Feng
- Sandia National Laboratories, Livermore, California 94550, USA.
| | | | - Krupa Ramasesha
- Sandia National Laboratories, Livermore, California 94550, USA.
| | - Vitalie Stavila
- Sandia National Laboratories, Livermore, California 94550, USA.
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47
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Taouali W, Alimi K, Sindhoo Nangraj A, Casida ME. Density-functional theory (DFT) and time-dependent DFT study of the chemical and physical origins of key photoproperties of end-group derivatives of a nonfullerene acceptor molecule for bulk heterojunction organic solar cells. J Comput Chem 2023; 44:2130-2148. [PMID: 37452478 DOI: 10.1002/jcc.27186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/18/2023] [Accepted: 06/22/2023] [Indexed: 07/18/2023]
Abstract
As emphasized in a recent review article (Chem. Rev. 2022, 122, 14180), organic solar cell (OSC) photoconversion efficiency has been rapidly evolving with results increasingly comparable to those of traditional inorganic solar cells. Historically, OSC performance improvement focused first on the morphology of P3HT:PC 61 BM solar cells then went through different stages to shift lately interest towards nonfullerene acceptors (NFAs) as a replacement ofPC 61 BM acceptor (ACC) molecule. Here, we use density-functional theory (DFT) and time-dependent DFT to investigate four novel NFAs of A-D-A (acceptor-donor-acceptor) form derived from the recently synthesized IDIC-4Cl (Dyes Pigm. 2019, 166, 196). Our level of theory is carefully evaluated for IDIC-4Cl and then applied to the four novel NFAs in order to understand how chemical modifications lead to physical changes in cyclic voltammetry (CV) frontier molecular orbital energies and absorption spectra in solution. Finally we design and apply a new type of Scharber plot for NFAs based upon some simple but we think reasonable assumptions. Unlike the original Scharber plots where a larger DON band gap favors a larger PCE, our modified Scharber plot reflects the fact that a smaller ACC band gap may favor PCE by filling in gaps in the DON acceptor spectrum. We predict that only the candidate molecule with the least good acceptor A, with the highest frontier molecular orbital energies, and one of the larger CV lowest unoccupied molecular orbital (LUMO) - highest unoccupied molecular orbital (HOMO) gaps, will yield a PM6:ACC PCE exceeding that of the parent IDIC-4Cl ACC. This candidate also shows the largest oscillator strength for the primary1 (HOMO, LUMO) charge- transfer transition and the largest degree of delocalization of charge transfer of any of the ACC molecules investigated here.
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Affiliation(s)
- Walid Taouali
- Laboratoire de Recherche (LR18ES19), Synthèse Asymétrique et Ingénierie Moléculaire de Matériaux Organiques pour l'Électroniques Organiques, Faculté des Sciences de Monastir, Université de Monastir, Monastir, Tunisia
| | - Kamel Alimi
- Laboratoire de Recherche (LR18ES19), Synthèse Asymétrique et Ingénierie Moléculaire de Matériaux Organiques pour l'Électroniques Organiques, Faculté des Sciences de Monastir, Université de Monastir, Monastir, Tunisia
- Institut National de Recherche et d'Analyse Physicochimique (INRAP) pole technologique Sidi Thabet, Ariana, Tunisia
| | - Asma Sindhoo Nangraj
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Mark E Casida
- Laboratoire de Spectrométrie, Interactions et Chimie théorique (SITh), Département de Chimie Moléculaire (DCM, UMR CNRS/UGA 5250), Institut de Chimie Moléculaire de Grenoble (ICMG, FR2607), Université Grenoble Alpes (UGA), Grenoble, France
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48
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Kitzmann WR, Hunger D, Reponen APM, Förster C, Schoch R, Bauer M, Feldmann S, van Slageren J, Heinze K. Electronic Structure and Excited-State Dynamics of the NIR-II Emissive Molybdenum(III) Analogue to the Molecular Ruby. Inorg Chem 2023; 62:15797-15808. [PMID: 37718553 DOI: 10.1021/acs.inorgchem.3c02186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Photoactive chromium(III) complexes saw a conceptual breakthrough with the discovery of the prototypical molecular ruby mer-[Cr(ddpd)2]3+ (ddpd = N,N'-dimethyl-N,N'-dipyridin-2-ylpyridine-2,6-diamine), which shows intense long-lived near-infrared (NIR) phosphorescence from metal-centered spin-flip states. In contrast to the numerous studies on chromium(III) photophysics, only 10 luminescent molybdenum(III) complexes have been reported so far. Here, we present the synthesis and characterization of mer-MoX3(ddpd) (1, X = Cl; 2, X = Br) and cisfac-[Mo(ddpd)2]3+ (cisfac-[3]3+), an isomeric heavy homologue of the prototypical molecular ruby. For cisfac-[3]3+, we found strong zero-field splitting using magnetic susceptibility measurements and electron paramagnetic resonance spectroscopy. Electronic spectra covering the spin-forbidden transitions show that the spin-flip states in mer-1, mer-2, and cisfac-[3]3+ are much lower in energy than those in comparable chromium(III) compounds. While all three complexes show weak spin-flip phosphorescence in NIR-II, the emission of cisfac-[3]3+ peaking at 1550 nm is particularly low in energy. Femtosecond transient absorption spectroscopy reveals a short excited-state lifetime of 1.4 ns, 6 orders of magnitude shorter than that of mer-[Cr(ddpd)2]3+. Using density functional theory and ab initio multireference calculations, we break down the reasons for this disparity and derive principles for the design of future stable photoactive molybdenum(III) complexes.
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Affiliation(s)
- Winald R Kitzmann
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - David Hunger
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Antti-Pekka M Reponen
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Roland Schoch
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
| | - Matthias Bauer
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
| | - Sascha Feldmann
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - Joris van Slageren
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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49
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Lijina MP, Benny A, Sebastian E, Hariharan M. Keeping the chromophores crossed: evidence for null exciton splitting. Chem Soc Rev 2023; 52:6664-6679. [PMID: 37606527 DOI: 10.1039/d3cs00176h] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Fundamental understanding of the supramolecular assemblies of organic chromophores and the development of design strategies have seen endless ripples of interest owing to their exciting photophysical properties and optoelectronic applications. The independent discovery of dye aggregates by Jelley and Scheibe was the commencement of the remarkable advancement in the field of aggregate photophysics. Subsequent research warranted an exceptional model for defining the exciton interactions in aggregates, proposed by Davydov, Kasha and co-workers, independently, based on the long-range Coulombic coupling. Fascinatingly, the orthogonally cross-stacked molecular transition dipole arrangement was foretold by Kasha to possess null exciton interaction leading to spectroscopically uncoupled molecular assembly, which lacked an experimental signature for decades. There have been several attempts to identify and probe atypical molecular aggregates for decoding their optical behaviour. Herein, we discuss the recent efforts in experimentally verifying the unusual exciton interactions supported with quantum chemical computations, primarily focusing on the less explored null exciton splitting. Exciton engineering can be realized through synthetic modifications that can additionally offer control over the assorted non-covalent interactions for orchestrating precise supramolecular assembly, along with molecular editing. The task of attaining a minimal excitonic coupling through an orthogonally cross-stacked crystalline architecture envisaged to offer a monomer-like optical behaviour was first reported in 1,7-dibromoperylene-3,4,9,10-tetracarboxylic tetrabutylester (PTE-Br2). The attempt to stitch molecules covalently in an orthogonal fashion to possess null excitonic character culminated in a spiro-conjugated perylenediimide dimer exhibiting a monomer-like spectroscopic signature. The computational and experimental efforts to map the emergent properties of the cross-stacked architecture are also discussed here. Using the null aggregates formed by the interference effects between CT-mediated and Coulombic couplings in the molecular array is another strategy for achieving monomer-like spectroscopic properties in molecular assemblies. Moreover, identifying supramolecular assemblies with precise angle-dependent properties can have implications in functional material design, and this review can provide insights into the uncharted realm of null exciton splitting.
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Affiliation(s)
- M P Lijina
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P. O., Vithura, Thiruvananthapuram, Kerala, 695551, India.
| | - Alfy Benny
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P. O., Vithura, Thiruvananthapuram, Kerala, 695551, India.
| | - Ebin Sebastian
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P. O., Vithura, Thiruvananthapuram, Kerala, 695551, India.
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P. O., Vithura, Thiruvananthapuram, Kerala, 695551, India.
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Mandal P, Panda AN. Conformational Effect on the Excitonic States of 2-Phenylpyridine Oligomers: Ab Initio Studies and Analysis. J Phys Chem A 2023; 127:7898-7907. [PMID: 37703054 DOI: 10.1021/acs.jpca.3c03601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
In this work, we report the effect of different conformations of 2-phenylpyridine oligomers ((PhPy)n=1-5) on the excited state properties from the results obtained at the RI-ADC(2)/def2-TZVP level. Three different conformers, namely, A, B, and C, are considered for each oligomer. All the oligomers of conformer A have linear-type structures, whereas conformers B and C form helical structures at n = 5 and n = 3, respectively. The differences in the geometries of the three conformers are reflected in the UV and CD spectra. The UV spectra of conformer A show high-intensity peaks compared to the conformers B and C, for each oligomer. While the helical oligomers of conformers B and C show high-intensity CD bands, the intensities of CD bands for all of the oligomers of conformer A are weaker. Analysis of the properties of the first five excited states in (PhPy)5 is carried out using three descriptors, and the results reveal that these are partially charge transfer states.
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Affiliation(s)
- Palak Mandal
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Aditya N Panda
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India
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