1
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Kazemi S, Alsaleh AZ, Karr PA, D'Souza F. Multimodular Wide-Band Capturing Nanohybrids: Role of Carbon Nanotubes in Slowing Charge Recombination in Supramolecular C 60-BisstyrylBODIPY-(Zinc Porphyrin) 2 Donor-Acceptor Molecular Cleft. J Am Chem Soc 2024; 146:13509-13518. [PMID: 38710108 DOI: 10.1021/jacs.4c02972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The importance of diameter-sorted single-wall carbon nanotubes (SWCNTs) noncovalently bound to a donor-acceptor molecular cleft, 1, in prolonging the lifetime of charge-separated states is successfully demonstrated. For this, using a multistep synthetic procedure, a wide-band capturing, multimodular, C60-bisstyrylBODIPY-(zinc porphyrin)2, molecular cleft 1, was newly synthesized and shown to bind diameter-sorted SWCNTs. The molecular cleft and its supramolecular assemblies were characterized by a suite of physicochemical techniques. Free-energy calculations suggested that both the (6,5) and (7,6) SWCNTs bound to 1 act as hole acceptors during the photoinduced sequential electron transfer events. Consequently, selective excitation of 1 in 1:SWCNT hybrids revealed a two-step electron transfer, leading to the formation of charge-separated states. Due to the distant separation of the cation and anion radical species within the supramolecules, improved lifetimes of the charge-separated states could be achieved. The present supramolecular strategy of improving charge separation involving SWCNTs and donor-acceptor molecular clefts highlights the potential application of these hybrid materials for various light energy harvesting and optoelectronic applications.
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Affiliation(s)
- Shahrzad Kazemi
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
| | - Ajyal Z Alsaleh
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
| | - Paul A Karr
- Department of Physical Sciences and Mathematics, Wayne State College, 1111 Main Street, Wayne, Nebraska 68787, United States
| | - Francis D'Souza
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
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2
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Alsaleh AZ, Pinjari D, Misra R, D'Souza F. Far-Red Excitation Induced Electron Transfer in Bis Donor-AzaBODIPY Push-Pull Systems; Role of Nitrogenous Donors in Promoting Charge Separation. Chemistry 2023; 29:e202301659. [PMID: 37401835 DOI: 10.1002/chem.202301659] [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: 05/24/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/05/2023]
Abstract
A far-red absorbing sensitizer, BF2 -chelated azadipyrromethane (azaBODIPY) has been employed as an electron acceptor to synthesize a series of push-pull systems linked with different nitrogenous electron donors, viz., N,N-dimethylaniline (NND), triphenylamine (TPA), and phenothiazine (PTZ) via an acetylene linker. The structural integrity of the newly synthesized push-pull systems was established by spectroscopic, electrochemical, spectroelectrochemical, and DFT computational methods. Cyclic and differential pulse voltammetry studies revealed different redox states and helped in the estimation of the energies of the charge-separated states. Further, spectroelectrochemical studies performed in a thin-layer optical cell revealed diagnostic peaks of azaBODIPY⋅- in the visible and near-IR regions. Free-energy calculations revealed the charge separation from one of the covalently linked donors to the 1 azaBODIPY* to yield Donor⋅+ -azaBODIPY⋅- to be energetically favorable in a polar solvent, benzonitrile, and the frontier orbitals generated on the optimized structures helped in assessing such a conclusion. Consequently, the steady-state emission studies revealed quenching of the azaBODIPY fluorescence in all of the investigated push-pull systems in benzonitrile and to a lesser extent in mildly polar dichlorobenzene, and nonpolar toluene. The femtosecond pump-probe studies revealed the occurrence of excited charge transfer (CT) in nonpolar toluene while a complete charge separation (CS) for all three push-pull systems in polar benzonitrile. The CT/CS products populated the low-lying 3 azaBODIPY* prior to returning to the ground state. Global target (GloTarAn) analysis of the transient data revealed the lifetime of the final charge-separated states (CSS) to be 195 ps for NND-derived, 50 ps for TPA-derived, and 85 ps for PTZ-derived push-pull systems in benzonitrile.
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Affiliation(s)
- Ajyal Z Alsaleh
- Department of Chemistry, University of North Texas, Denton, TX 76203-5017, USA
| | - Dilip Pinjari
- Department of Chemistry, Indian Institute of Technology, Indore, 453552, India
| | - Rajneesh Misra
- Department of Chemistry, Indian Institute of Technology, Indore, 453552, India
| | - Francis D'Souza
- Department of Chemistry, University of North Texas, Denton, TX 76203-5017, USA
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3
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Follana-Berná J, Dawson A, Kaswan RR, Seetharaman S, Karr PA, Sastre-Santos Á, D'Souza F. π-Extended Pyrazinepyrene-Fused Zinc Phthalocyanines: Synthesis and Excited-State Charge Separation Involving Coordinated C 60. J Phys Chem A 2023. [PMID: 37467488 DOI: 10.1021/acs.jpca.3c02738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
A series of pyrazinepyrene-fused zinc phthalocyanines (ZnPc-Pyrn) have been newly synthesized by reacting quinoxaline and the corresponding diamino-functionalized phthalocyanines as a new class of π-extended phthalocyanine systems. Bathochromically shifted absorption as a function of the number of pyrazinepyrene entities due to extended π-conjugation and quenched fluorescence due to the presence of fused pyrazinepyrene were witnessed. The electronic structures of these phthalocyanines were probed by systematic computational and electrochemical studies, while the excited-state properties were examined by pump-probe spectroscopies operating at the femto- and nanosecond time scales. Similar to the excited singlet lifetimes, the excited triplet states also revealed diminished lifetimes with an increased number of pyrazinepyrene entities. Further, the coordinatively unsaturated zinc in these molecules was coordinated with phenyl imidazole-functionalized fullerene, ImC60, to form a new series of donor-acceptor conjugates. Upon full characterization of these conjugates, the occurrence of excited-state charge separation was established by transient pump-probe spectroscopy, covering wide temporal and spatial regions. The lifetime of the final charge-separated states was ∼2 ns and decreased with an increase in the number of fused pyrazinepyrene units.
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Affiliation(s)
- Jorge Follana-Berná
- Área de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández de Elche, Avda. de la Universidad s/n, 03202 Elche, Spain
| | - Andrew Dawson
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
| | - Ram R Kaswan
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
| | - Sairaman Seetharaman
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
| | - Paul A Karr
- Department of Physical Sciences and Mathematics, Wayne State College, 1111 Main Street, Wayne, Nebraska 68787, United States
| | - Ángela Sastre-Santos
- Área de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández de Elche, Avda. de la Universidad s/n, 03202 Elche, Spain
| | - Francis D'Souza
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
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4
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Jang Y, Sekaran B, Singh PP, Misra R, D'Souza F. Accelerated Intramolecular Charge Transfer in Tetracyanobutadiene- and Expanded Tetracyanobutadiene-Incorporated Asymmetric Triphenylamine-Quinoxaline Push-Pull Conjugates. J Phys Chem A 2023; 127:4455-4462. [PMID: 37192382 DOI: 10.1021/acs.jpca.3c01732] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The excited-state properties of an asymmetric triphenylamine-quinoxaline push-pull system wherein triphenylamine and quinoxaline take up the roles of an electron donor and acceptor, respectively, are initially investigated. Further, in order to improve the push-pull effect, powerful electron acceptors, viz., 1,1,4,4-tetracyanobutadiene (TCBD) and cyclohexa-2,5-diene-1,4-diylidene-expanded tetracyanobutadiene (also known as expanded-TCBD or exTCBD), have been introduced into the triphenylamine-quinoxaline molecular framework using a catalyst-free [2 + 2] cycloaddition-retroelectrocyclization reaction. The presence of these electron acceptors caused strong ground-state polarization extending the absorption well into the near-IR region accompanied by strong fluorescence quenching due to intramolecular charge transfer (CT). Systematic studies were performed using a suite of spectral, electrochemical, computational, and pump-probe spectroscopic techniques to unravel the intramolecular CT mechanism and to probe the role of TCBD and exTCBD in promoting excited-state CT and separation events. Faster CT in exTCBD-derived compared to that in TCBD-derived push-pull systems has been witnessed in polar benzonitrile.
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Affiliation(s)
- Youngwoo Jang
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
| | - Bijesh Sekaran
- Department of Chemistry, Indian Institute of Technology, Indore 453552, India
| | - Prabal P Singh
- Department of Chemistry, GLA University, NH-2, Delhi-Mathura highways, Mathura, Uttar Pradesh 282004, India
| | - Rajneesh Misra
- Department of Chemistry, Indian Institute of Technology, Indore 453552, India
| | - Francis D'Souza
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
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5
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Sheokand M, Alsaleh AZ, D'Souza F, Misra R. Excitation Wavelength-Dependent Charge Stabilization in Highly Interacting Phenothiazine Sulfone-Derived Donor-Acceptor Constructs. J Phys Chem B 2023; 127:2761-2773. [PMID: 36938962 DOI: 10.1021/acs.jpcb.2c08472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Prolonging the lifetime of charge-separated states (CSS) is of paramount importance in artificial photosynthetic donor-acceptor (DA) constructs to build the next generation of light-energy-harvesting devices. This becomes especially important when the DA constructs are closely spaced and highly interacting. In the present study, we demonstrate extending the lifetime of the CSS in highly interacting DA constructs by making use of the triplet excited state of the electron donor and with the help of excitation wavelength selectivity. To demonstrate this, π-conjugated phenothiazine sulfone-based push-pull systems, PTS2-PTS6 have been newly designed and synthesized via the Pd-catalyzed Sonogashira cross-coupling followed by [2 + 2] cycloaddition-retroelectrocyclization reactions. Modulation of the spectral and photophysical properties of phenothiazine sulfones (PTZSO2) and terminal phenothiazines (PTZ) was possible by incorporating powerful electron acceptors, 1,1,4,4-tetracyanobutadiene (TCBD) and cyclohexa-2,5-diene-1,4-diylidene-expanded TCBD (exTCBD). The quadrupolar PTS2 displayed solvatochromism, aggregation-induced emission, and mechanochromic behaviors. From the energy calculations, excitation wavelength-dependent charge stabilization was envisioned in PTS2-PTS6, and the subsequent pump-probe spectroscopic studies revealed charge stabilization when the systems were excited at the locally excited peak positions, while such effect was minimal when the samples were excited at wavelengths corresponding to the CT transitions. This work reveals the impact of wavelength selectivity to induce charge separation from the triplet excited state in ultimately prolonging the lifetime of CCS in highly interacting push-pull systems.
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Affiliation(s)
- Manju Sheokand
- Department of Chemistry, Indian Institute of Technology, Indore 453552, India
| | - Ajyal Z Alsaleh
- Department of Chemistry, University of North Texas, Denton, Texas 76203-5017, United States
| | - Francis D'Souza
- Department of Chemistry, University of North Texas, Denton, Texas 76203-5017, United States
| | - Rajneesh Misra
- Department of Chemistry, Indian Institute of Technology, Indore 453552, India
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6
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Kazemi S, Jang Y, Liyanage A, Karr PA, D'Souza F. A Carbon Nanotube Binding BODIPY‐C
60
Nano Tweezer: Charge Stabilization through Sequential Electron Transfer. Angew Chem Int Ed Engl 2022; 61:e202212474. [DOI: 10.1002/anie.202212474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Indexed: 11/13/2022]
Affiliation(s)
- Shahrzad Kazemi
- Department of Chemistry University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
| | - Youngwoo Jang
- Department of Chemistry University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
| | - Anuradha Liyanage
- Department of Chemistry University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
| | - Paul A. Karr
- Department of Physical Sciences and Mathematics Wayne State College 1111 Main Street Wayne Nebraska, 68787 USA
| | - Francis D'Souza
- Department of Chemistry University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
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7
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Arellano LM, Gobeze HB, Jang Y, Barrejón M, Parejo C, Álvarez JC, Gómez‐Escalonilla MJ, Sastre‐Santos Á, D'Souza F, Langa F. Formation and Photoinduced Electron Transfer in Porphyrin‐ and Phthalocyanine‐Bearing N‐Doped Graphene Hybrids Synthesized by Click Chemistry. Chemistry 2022; 28:e202200254. [PMID: 35254708 PMCID: PMC9314890 DOI: 10.1002/chem.202200254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Luis M. Arellano
- Universidad de Castilla-La Mancha Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL) Avda. Carlos III, s/n 45071- Toledo Spain
| | - Habtom B. Gobeze
- Department of Chemistry and Materials Science and Engineering University of North Texas Denton TX 76203-5017 USA
| | - Youngwoo Jang
- Department of Chemistry and Materials Science and Engineering University of North Texas Denton TX 76203-5017 USA
| | - Myriam Barrejón
- Neural Repair and Biomaterials Laboratory Hospital Nacional de Parapléjicos (SESCAM) Finca la Peraleda s/n 45071 Toledo Spain
| | - Concepción Parejo
- Área de Química Orgánica, Instituto de Bioingeniería Universidad Miguel Hernández Avda. de la Universidad, s/n Elche 03202 Spain
| | - Julio C. Álvarez
- Área de Química Orgánica, Instituto de Bioingeniería Universidad Miguel Hernández Avda. de la Universidad, s/n Elche 03202 Spain
| | - María J. Gómez‐Escalonilla
- Universidad de Castilla-La Mancha Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL) Avda. Carlos III, s/n 45071- Toledo Spain
| | - Ángela Sastre‐Santos
- Área de Química Orgánica, Instituto de Bioingeniería Universidad Miguel Hernández Avda. de la Universidad, s/n Elche 03202 Spain
| | - Francis D'Souza
- Department of Chemistry and Materials Science and Engineering University of North Texas Denton TX 76203-5017 USA
| | - Fernando Langa
- Universidad de Castilla-La Mancha Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL) Avda. Carlos III, s/n 45071- Toledo Spain
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8
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Wu T, Brooksby PA, Fitchett CM, Downard AJ. Immobilisation of Iron Porphyrin from an Equilibrium Solution with Diazonium‐Functionalised Axial Ligand: Dependence of Film Composition on Grafting Potential. ChemElectroChem 2021. [DOI: 10.1002/celc.202100712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ting Wu
- School of Physical and Chemical Sciences University of Canterbury Christchurch 8140 New Zealand
| | - Paula A. Brooksby
- School of Physical and Chemical Sciences University of Canterbury Christchurch 8140 New Zealand
| | - Christopher M. Fitchett
- School of Physical and Chemical Sciences University of Canterbury Christchurch 8140 New Zealand
| | - Alison J. Downard
- School of Physical and Chemical Sciences University of Canterbury Christchurch 8140 New Zealand
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9
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Caballero R, Barrejón M, Cerdá J, Aragó J, Seetharaman S, de la Cruz P, Ortí E, D’Souza F, Langa F. Self-Assembly-Directed Organization of a Fullerene-Bisporphyrin into Supramolecular Giant Donut Structures for Excited-State Charge Stabilization. J Am Chem Soc 2021; 143:11199-11208. [PMID: 34260220 PMCID: PMC8397305 DOI: 10.1021/jacs.1c05133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Indexed: 11/29/2022]
Abstract
Functional materials composed of spontaneously self-assembled electron donor and acceptor entities capable of generating long-lived charge-separated states upon photoillumination are in great demand as they are key in building the next generation of light energy harvesting devices. However, creating such well-defined architectures is challenging due to the intricate molecular design, multistep synthesis, and issues associated in demonstrating long-lived electron transfer. In this study, we have accomplished these tasks and report the synthesis of a new fullerene-bis-Zn-porphyrin e-bisadduct by tether-directed functionalization of C60 via a multistep synthetic protocol. Supramolecular oligomers were subsequently formed involving the two porphyrin-bearing arms embracing a fullerene cage of the vicinal molecule as confirmed by MALDI-TOF spectrometry and variable temperature NMR. In addition, the initially formed worm-like oligomers are shown to evolve to generate donut-like aggregates by AFM monitoring that was also supported by theoretical calculations. The final supramolecular donuts revealed an inner cavity size estimated as 23 nm, close to that observed in photosynthetic antenna systems. Upon systematic spectral, computational, and electrochemical studies, an energy level diagram was established to visualize the thermodynamic feasibility of electron transfer in these donor-acceptor constructs. Subsequently, transient pump-probe spectral studies covering the wide femtosecond-to-millisecond time scale were performed to confirm the formation of long-lived charge-separated states. The lifetime of the final charge-separated state was about 40 μs, thus highlighting the significance of the current approach of building giant self-organized donor-acceptor assemblies for light energy harvesting applications.
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Affiliation(s)
- Rubén Caballero
- Instituto
de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, Campus de la Fábrica de Armas, 45071 Toledo, Spain
| | - Myriam Barrejón
- Instituto
de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, Campus de la Fábrica de Armas, 45071 Toledo, Spain
- Neural
Repair and Biomaterials Laboratory, Hospital
Nacional de Parapléjicos (SESCAM), Finca la Peraleda s/n, 45071 Toledo, Spain
| | - Jesús Cerdá
- Instituto
de Ciencia Molecular, Universidad de Valencia, 46950 Paterna, Spain
| | - Juan Aragó
- Instituto
de Ciencia Molecular, Universidad de Valencia, 46950 Paterna, Spain
| | - Sairaman Seetharaman
- Department
of Chemistry, University of North Texas, 1155 Union Circle 305070, Denton, Texas 76203-5017, United States
| | - Pilar de la Cruz
- Instituto
de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, Campus de la Fábrica de Armas, 45071 Toledo, Spain
| | - Enrique Ortí
- Instituto
de Ciencia Molecular, Universidad de Valencia, 46950 Paterna, Spain
| | - Francis D’Souza
- Department
of Chemistry, University of North Texas, 1155 Union Circle 305070, Denton, Texas 76203-5017, United States
| | - Fernando Langa
- Instituto
de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, Campus de la Fábrica de Armas, 45071 Toledo, Spain
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10
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Wu T, Fitchett CM, Brooksby PA, Downard AJ. Building Tailored Interfaces through Covalent Coupling Reactions at Layers Grafted from Aryldiazonium Salts. ACS APPLIED MATERIALS & INTERFACES 2021; 13:11545-11570. [PMID: 33683855 DOI: 10.1021/acsami.0c22387] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Aryldiazonium ions are widely used reagents for surface modification. Attractive aspects of their use include wide substrate compatibility (ranging from plastics to carbons to metals and metal oxides), formation of stable covalent bonding to the substrate, simplicity of modification methods that are compatible with organic and aqueous solvents, and the commercial availability of many aniline precursors with a straightforward conversion to the active reagent. Importantly, the strong bonding of the modifying layer to the surface makes the method ideally suited to further on-surface (postfunctionalization) chemistry. After an initial grafting from a suitable aryldiazonium ion to give an anchor layer, a target species can be coupled to the layer, hugely expanding the range of species that can be immobilized. This strategy has been widely employed to prepare materials for numerous applications including chemical sensors, biosensors, catalysis, optoelectronics, composite materials, and energy conversion and storage. In this Review our goal is first to summarize how a target species with a particular functional group may be covalently coupled to an appropriate anchor layer. We then review applications of the resulting materials.
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Affiliation(s)
- Ting Wu
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, Christchurch, New Zealand
| | - Christopher M Fitchett
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, Christchurch, New Zealand
| | - Paula A Brooksby
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
| | - Alison J Downard
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, Christchurch, New Zealand
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11
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Yadav IS, Alsaleh AZ, Misra R, D'Souza F. Charge stabilization via electron exchange: excited charge separation in symmetric, central triphenylamine derived, dimethylaminophenyl-tetracyanobutadiene donor-acceptor conjugates. Chem Sci 2020; 12:1109-1120. [PMID: 34163878 PMCID: PMC8179009 DOI: 10.1039/d0sc04648e] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Photoinduced charge separation in donor-acceptor conjugates plays a pivotal role in technology breakthroughs, especially in the areas of efficient conversion of solar energy into electrical energy and fuels. Extending the lifetime of the charge separated species is a necessity for their practical utilization, and this is often achieved by following the mechanism of natural photosynthesis where the process of electron/hole migration occurs distantly separating the radical ion pairs. Here, we hypothesize and demonstrate a new mechanism to stabilize the charge separated states via the process of electron exchange among the different acceptor entities in multimodular donor-acceptor conjugates. For this, star-shaped, central triphenylamine derived, dimethylamine-tetracyanobutadiene conjugates have been newly designed and characterized. Electron exchange was witnessed upon electroreduction in conjugates having multiple numbers of electron acceptors. Using ultrafast spectroscopy, the occurrence of excited state charge separation, and the effect of electron exchange in prolonging the lifetime of charge separated states in the conjugates having multiple acceptors have been successfully demonstrated. This work constitutes the first example of stabilizing charge-separated states via the process of electron exchange.
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Affiliation(s)
- Indresh S Yadav
- Department of Chemistry, Indian Institute of Technology Indore 453552 India
| | - Ajyal Z Alsaleh
- Department of Chemistry, University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
| | - Rajneesh Misra
- Department of Chemistry, Indian Institute of Technology Indore 453552 India
| | - Francis D'Souza
- Department of Chemistry, University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
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12
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Arellano LM, Gobeze HB, Gómez-Escalonilla MJ, Fierro JLG, D'Souza F, Langa F. Triplet photosensitizer-nanotube conjugates: synthesis, characterization and photochemistry of charge stabilizing, palladium porphyrin/carbon nanotube conjugates. NANOSCALE 2020; 12:9890-9898. [PMID: 32347282 DOI: 10.1039/d0nr02136a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The ability of a triplet photosensitizer to generate long-lived charge separated states, in contrast to traditionally used singlet photosensitizers, in covalently functionalized single-walled carbon nanotube hybrids has been investigated. Enriched single-walled carbon nanotubes with two diameters, namely (6,5) and (7,6), were covalently modified to carry a charge-stabilizing triplet photosensitizer derived from a palladium porphyrin. The nanohybrids were fully characterized and the presence of intramolecular interactions between the porphyrin and nanotubes was established from various spectroscopic, imaging, electrochemical and thermochemical studies. Photoluminescence of palladium porphyrin was found to be quantitatively quenched in the presence of covalently appended SWCNTs and this quenching is due to excited state charge separation and has been established by femtosecond transient absorption studies. Owing to the presence of the triplet photosensitizer, the charge separated states lasted over 3 ns, i.e., much longer than those reported earlier for singlet photosensitizer-derived nanotube hybrids. The nanohybrids also exhibited efficient photocatalytic behavior in experiments involving electron pooling of one-electron reduced methyl viologen in the presence of a sacrificial electron donor. Higher yields of photoproducts were achieved from the present donor-acceptor nanohybrids when compared with those of singlet photosensitizer-derived nanohybrids, more so for (6,5) nanotube derived hybrids compared to (7,6) nanotube derived hybrids. The present findings highlight the importance of triplet photosensitizer derived nanohybrids in artificial photosynthesis of charge separation and photocatalytic applicatons.
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Affiliation(s)
- Luis M Arellano
- Universidad de Castilla-La Mancha, Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), 45071-Toledo, Spain.
| | - Habtom B Gobeze
- Chemistry and Materials Science and Engineering, University of North Texas, 76203-5017 Denton, TX, USA. Francis.D'
| | - María J Gómez-Escalonilla
- Universidad de Castilla-La Mancha, Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), 45071-Toledo, Spain.
| | - José Luis G Fierro
- Instituto de Catálisis y Petroleoquímica, CSIC, Cantoblanco, 28049, Madrid, Spain.
| | - Francis D'Souza
- Chemistry and Materials Science and Engineering, University of North Texas, 76203-5017 Denton, TX, USA. Francis.D'
| | - Fernando Langa
- Universidad de Castilla-La Mancha, Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), 45071-Toledo, Spain.
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Garrido M, Volland MK, Münich PW, Rodríguez-Pérez L, Calbo J, Ortí E, Herranz MÁ, Martín N, Guldi DM. Mono- and Tripodal Porphyrins: Investigation on the Influence of the Number of Pyrene Anchors in Carbon Nanotube and Graphene Hybrids. J Am Chem Soc 2019; 142:1895-1903. [DOI: 10.1021/jacs.9b10772] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marina Garrido
- Department of Organic Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Michel K. Volland
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander University of Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Peter W. Münich
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander University of Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Laura Rodríguez-Pérez
- Department of Organic Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Joaquín Calbo
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, c/Catedrático José Beltrán, 2, 46980 Paterna, Spain
| | - Enrique Ortí
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, c/Catedrático José Beltrán, 2, 46980 Paterna, Spain
| | - M. Ángeles Herranz
- Department of Organic Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Nazario Martín
- Department of Organic Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, 28040 Madrid, Spain
- IMDEA Nanoscience, C/Faraday 9, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander University of Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
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