1
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Sandoval JS, McCamant DW. The Best Models of Bodipy's Electronic Excited State: Comparing Predictions from Various DFT Functionals with Measurements from Femtosecond Stimulated Raman Spectroscopy. J Phys Chem A 2023; 127:8238-8251. [PMID: 37751471 PMCID: PMC10561280 DOI: 10.1021/acs.jpca.3c05040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 09/11/2023] [Indexed: 09/28/2023]
Abstract
Density functional theory (DFT) and time-dependent DFT (TD-DFT) are pivotal approaches for modeling electronically excited states of molecules. However, choosing a DFT exchange-correlation functional (XCF) among the myriad of alternatives is an overwhelming task that can affect the interpretation of results and lead to erroneous conclusions. The performance of these XCFs to describe the excited-state properties is often addressed by comparing them with high-level wave function methods or experimentally available vertical excitation energies; however, this is a limited analysis that relies on evaluation of a single point in the excited-state potential energy surface (PES). Different strategies have been proposed but are limited by the difficulty of experimentally accessing the electronic excited-state properties. In this work, we have tested the performance of 12 different XCFs and TD-DFT to describe the excited-state potential energy surface of Bodipy (2,6-diethyl-1,3,5,7-tetramethyl-8-phenyldipyrromethene difluoroborate). We compare those results with resonance Raman spectra collected by using femtosecond stimulated Raman spectroscopy (FSRS). By simultaneously fitting the absorption spectrum, fluorescence spectrum, and all of the resonance Raman excitation profiles within the independent mode displaced harmonic oscillator (IMDHO) formalism, we can describe the PES at the Franck-Condon (FC) region and determine the solvent and intramolecular reorganization energy after relaxation. This allows a direct comparison of the TD-DFT output with experimental observables. Our analysis reveals that using vertical absorption energies might not be a good criterion to determine the best XCF for a given molecular system and that FSRS opens up a new way to benchmark the excited-state performance of XCFs of fluorescent dyes.
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Affiliation(s)
- Juan S. Sandoval
- Department of Chemistry, University
of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
| | - David W. McCamant
- Department of Chemistry, University
of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
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2
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Iordache SM, Iordache AM, Zubarev A, Caramizoiu S, Grigorescu CEA, Marinescu S, Giuglea C. Spectro-Electrochemical Properties of A New Non-Enzymatic Modified Working Electrode Used for Histamine Assessment in the Diagnosis of Food Poisoning. Foods 2023; 12:2908. [PMID: 37569178 PMCID: PMC10417452 DOI: 10.3390/foods12152908] [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: 05/22/2023] [Revised: 07/24/2023] [Accepted: 07/29/2023] [Indexed: 08/13/2023] Open
Abstract
We successfully prepared a non-enzymatic sensor based on a graphene-thiophene composite for histamine detection. The self-assembling properties of the thiophene onto Au support and the high electrical conductivity of graphene encouraged the choice of this type of composite. The composite was deposited via electrochemical polymerization onto the Au layer of a screen-printed microelectrode. The electropolymerization and electrochemical detection of histamine were both achieved by cyclic voltammetry. Two types of electrolytes were used for the electrochemical detection: (a) phosphate buffer solution (PBS), which showed low-intensity redox peaks for histamine; and (b) trichloroacetic acid (TCA) 0.01 M, which showed improved results over PBS and did not damage the microelectrode. For the concentration range of 100-200 mg/kg, the sensor shows a linear regression pattern for the oxidation peak fitted on the equation Ipa = 123.412 + 0.49933 ×x, with R2 = 0.94178. The lowest limit of detection was calculated to be 13.8 mg/kg and the limit of quantification was calculated at 46 mg/kg. These results are important since by monitoring the amount of histamine in a food product, early onset of spoilage can be easily detected, thus reducing foodborne poisoning and food waste (by recycling products that are still edible).
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Affiliation(s)
- Stefan-Marian Iordache
- Optospintronics Department, National Institute for Research and Development for Optoelectronics—INOE 2000, Atomistilor 409, 077125 Magurele, Romania; (S.-M.I.); (C.E.A.G.)
| | - Ana-Maria Iordache
- Optospintronics Department, National Institute for Research and Development for Optoelectronics—INOE 2000, Atomistilor 409, 077125 Magurele, Romania; (S.-M.I.); (C.E.A.G.)
| | - Alexei Zubarev
- National Institute for Laser, Plasma and Radiation Physics, 077125 Magurele, Romania
| | - Stefan Caramizoiu
- National Institute for R&D in Microtechnologies IMT-Bucharest, 126A Erou Iancu Nicolae Str., 077190 Voluntari, Romania;
| | - Cristiana Eugenia Ana Grigorescu
- Optospintronics Department, National Institute for Research and Development for Optoelectronics—INOE 2000, Atomistilor 409, 077125 Magurele, Romania; (S.-M.I.); (C.E.A.G.)
| | - Silviu Marinescu
- Department of Plastic Surgery, University of Medicine and Pharmacy “Carol Davila”, Eroii Sanitari Bvd., No. 8, Sector 5, 050471 Bucharest, Romania (C.G.)
| | - Carmen Giuglea
- Department of Plastic Surgery, University of Medicine and Pharmacy “Carol Davila”, Eroii Sanitari Bvd., No. 8, Sector 5, 050471 Bucharest, Romania (C.G.)
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3
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Roy P, Al-Kahtani F, Cammidge AN, Meech SR. Solvent Tuning Excited State Structural Dynamics in a Novel Bianthryl. J Phys Chem Lett 2023; 14:253-259. [PMID: 36594925 PMCID: PMC9841557 DOI: 10.1021/acs.jpclett.2c03469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
Symmetry breaking charge separation (SBCS) is central to photochemical energy conversion. The widely studied 9,9-bianthryl (9,9'BA) is the prototype, but the role of bianthryl structure is hardly investigated. Here we investigate excited state structural dynamics in a bianthryl of reduced symmetry, 1,9-bianthryl (1,9'BA), through ultrafast electronic and vibrational spectroscopy. Resonance selective Raman in polar solvents reveals a Franck-Condon state mode that disappears concomitant with the rise of ring breathing modes of radical species. Solvent-dependent dynamics show that CS is driven by solvent orientational motion, as in 9,9'BA. In nonpolar solvents the excited state undergoes multistep structural relaxation, including subpicosecond Franck-Condon state decay and biexponential diffusion-controlled structural evolution to a distorted slightly polar state. These data suggest two possible routes to SBCS; the established solvent driven pathway in rapidly relaxing polar solvents and, in slowly relaxing media, initial intramolecular reorganization to a polar structure which drives solvent orientational relaxation.
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4
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Addison K, Roy P, Bressan G, Skudaite K, Robb J, Bulman Page PC, Ashworth EK, Bull JN, Meech SR. Photophysics of the red-form Kaede chromophore. Chem Sci 2023; 14:3763-3775. [PMID: 37035701 PMCID: PMC10074405 DOI: 10.1039/d3sc00368j] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/08/2023] [Indexed: 03/18/2023] Open
Abstract
The chromophore responsible for colour switching in the optical highlighting protein Kaede has unexpectedly complicated excited state dynamics, which are measured and analysed here. This will inform the development of new imaging proteins.
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Affiliation(s)
- Kiri Addison
- School of Chemistry, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - Palas Roy
- School of Chemistry, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - Giovanni Bressan
- School of Chemistry, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - Karolina Skudaite
- School of Chemistry, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - Josh Robb
- School of Chemistry, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | | | - Eleanor K. Ashworth
- School of Chemistry, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - James N. Bull
- School of Chemistry, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
| | - Stephen R. Meech
- School of Chemistry, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
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5
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Burns KH, Quincy TJ, Elles CG. Excited-state resonance Raman spectroscopy probes the sequential two-photon excitation mechanism of a photochromic molecular switch. J Chem Phys 2022; 157:234302. [PMID: 36550048 DOI: 10.1063/5.0126974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Some diarylethene molecular switches have a low quantum yield for cycloreversion when excited by a single photon, but react more efficiently following sequential two-photon excitation. The increase in reaction efficiency depends on both the relative time delay and the wavelength of the second photon. This paper examines the wavelength-dependent mechanism for sequential excitation using excited-state resonance Raman spectroscopy to probe the ultrafast (sub-30 fs) dynamics on the upper electronic state following secondary excitation. The approach uses femtosecond stimulated Raman scattering (FSRS) to measure the time-gated, excited-state resonance Raman spectrum in resonance with two different excited-state absorption bands. The relative intensities of the Raman bands reveal the initial dynamics in the higher-lying states, Sn, by providing information on the relative gradients of the potential energy surfaces that are accessed via secondary excitation. The excited-state resonance Raman spectra reveal specific modes that become enhanced depending on the Raman excitation wavelength, 750 or 400 nm. Many of the modes that become enhanced in the 750 nm FSRS spectrum are assigned as vibrational motions localized on the central cyclohexadiene ring. Many of the modes that become enhanced in the 400 nm FSRS spectrum are assigned as motions along the conjugated backbone and peripheral phenyl rings. These observations are consistent with earlier measurements that showed higher efficiency following secondary excitation into the lower excited-state absorption band and illustrate a powerful new way to probe the ultrafast dynamics of higher-lying excited states immediately following sequential two-photon excitation.
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Affiliation(s)
- Kristen H Burns
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
| | - Timothy J Quincy
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
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6
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Burns KH, Elles CG. Ultrafast Dynamics of a Molecular Switch from Resonance Raman Spectroscopy: Comparing Visible and UV Excitation. J Phys Chem A 2022; 126:5932-5939. [PMID: 36026439 DOI: 10.1021/acs.jpca.2c05435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Resonance Raman spectroscopy probes the ultrafast dynamics of a diarylethene (DAE) molecular switch following excitation into the first two optical absorption bands. Mode-specific resonance enhancements for Raman excitation at visible (750-560 nm) and near-UV (420-390 nm) wavelengths compared with the calculated and experimental off-resonance Raman spectrum at 785 nm reveal different Franck-Condon active vibrations for the two electronically excited states. The resonance enhancements at visible wavelengths are consistent with initial motion on the first excited-state that promotes the cycloreversion reaction, whereas the enhancements for excitation at near-UV wavelengths highlight motions involving conjugated backbone and phenyl ring stretching modes that are orthogonal to the reaction coordinate. The results support a mechanism involving rapid internal conversion from the higher-lying state followed by cycloreversion on the first excited state. These observations provide new information about the reactivity of DAE derivatives following excitation in the visible and near-UV.
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Affiliation(s)
- Kristen H Burns
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Christopher G Elles
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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7
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Lee S, Jen M, Lee G, Jang T, Pang Y. Intramolecular charge transfer of a push-pull chromophore with restricted internal rotation of an electron donor. Phys Chem Chem Phys 2022; 24:5794-5802. [PMID: 35195633 DOI: 10.1039/d1cp05541k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Intramolecular charge transfer (ICT) of 4-(dicyanomethylene)-2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran (LD688) in DMSO solution was investigated by femtosecond stimulated Raman spectroscopy (FSRS) with 403 nm excitation. The molecular structure of LD688 is similar to that of a well-known push-pull chromophore, 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM), except that the internal rotation of the electron-donating dimethylamino group is restricted with the introduction of the julolidine moiety. Upon photo-excitation, LD688 shows an ultrafast (1.0 ps) ICT followed by the vibrational relaxation (3-8 ps) in the charge-transfer (CT) state. Two distinct Raman spectra of LD688 in the locally excited (LE) and CT state of the S1 state were retrieved from FSRS measurements. Based on the time-dependent density functional theory (TDDFT) simulations, a "twisted" julolidine geometry of LD688 was proposed for the ICT state, which was further confirmed in comparison to the spectral changes of several push-pull chromophores with the π-conjugated backbone of stilbene, biphenyl, styrylpyran, styrylpyridinium, and styrene in terms of the skeletal vibrational modes of ν19b,py, νCC,ph, and νCN.
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Affiliation(s)
- Sebok Lee
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Myungsam Jen
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Gisang Lee
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Taehyung Jang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Yoonsoo Pang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
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8
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9
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Kim W, Tahara S, Kuramochi H, Takeuchi S, Kim T, Tahara T, Kim D. Mode‐Specific Vibrational Analysis of Exciton Delocalization and Structural Dynamics in Conjugated Oligomers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
- Current address: Department of Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
| | - Shinya Tahara
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Current address: Graduate School of Pharmaceutical Sciences Tohoku University 6-3 Aramaki-aza-Aoba, Aoba-ku Sendai 980-8578 Japan
| | - Hikaru Kuramochi
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
- JST PRESTO 4-1-8 Honcho Kawaguchi 332-0012 Japan
- Current address: Research Center of Integrative Molecular Systems (CIMoS) Institute for Molecular Science 38 Nishigo-Naka, Myodaji Okazaki 444-8585 Japan
| | - Satoshi Takeuchi
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
- Current address: Graduate School of Material Science University of Hyogo 3-2-1 Koto Kamigori Ako 678-1297 Japan
| | - Taeyeon Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
- Current address: Department of Chemistry and Institute for Sustainability and Energy at Northwestern Northwestern University Evanston IL 60208-3113 USA
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
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10
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Kim W, Tahara S, Kuramochi H, Takeuchi S, Kim T, Tahara T, Kim D. Mode-Specific Vibrational Analysis of Exciton Delocalization and Structural Dynamics in Conjugated Oligomers. Angew Chem Int Ed Engl 2021; 60:16999-17008. [PMID: 33730430 DOI: 10.1002/anie.202102168] [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: 02/10/2021] [Indexed: 11/09/2022]
Abstract
Exciton delocalization in organic semiconducting polymers, affected by structures at a molecular level, plays a crucial role in modulating relaxation pathways, such as charge generation and singlet fission, which can boost device efficiency. However, the structural diversity of polymers and broad signals from typical electronic spectroscopy have their limits when it comes to revealing the interplay between local structures and exciton delocalization. To tackle these problems, we apply femtosecond stimulated Raman spectroscopy in archetypical conjugated oligothiophenes with different chain lengths. We observed Raman frequency dispersions of symmetric bond stretching modes and mode-specific kinetics in the S1 Raman spectra, which underpins the subtle and complex interplay between exciton delocalization and bond length alternation along the conjugation coordinate. Our results provide a more general picture of exciton delocalization in the context of molecular structures for conjugated materials.
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Affiliation(s)
- Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea.,Current address: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Shinya Tahara
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Current address: Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Hikaru Kuramochi
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan.,JST PRESTO, 4-1-8 Honcho, Kawaguchi, 332-0012, Japan.,Current address: Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, 38 Nishigo-Naka, Myodaji, Okazaki, 444-8585, Japan
| | - Satoshi Takeuchi
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan.,Current address: Graduate School of Material Science, University of Hyogo, 3-2-1 Koto, Kamigori, Ako, 678-1297, Japan
| | - Taeyeon Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea.,Current address: Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL, 60208-3113, USA
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea
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11
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Tachibana SR, Tang L, Chen C, Zhu L, Takeda Y, Fushimi K, Seevers TK, Narikawa R, Sato M, Fang C. Transient electronic and vibrational signatures during reversible photoswitching of a cyanobacteriochrome photoreceptor. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 250:119379. [PMID: 33401182 DOI: 10.1016/j.saa.2020.119379] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/12/2020] [Accepted: 12/19/2020] [Indexed: 06/12/2023]
Abstract
Cyanobacteriochromes (CBCRs) are an emerging class of photoreceptors that are distant relatives of the phytochromes family. Unlike phytochromes, CBCRs have gained popularity in optogenetics due to their highly diverse spectral properties spanning the UV to near-IR region and only needing a single compact binding domain. AnPixJg2 is a CBCR that can reversibly photoswitch between its red-absorbing (15ZPr) and green-absorbing (15EPg) forms of the phycocyanobilin (PCB) cofactor. To reveal primary events of photoconversion, we implemented femtosecond transient absorption spectroscopy with a homemade LED box and a miniature peristaltic pump flow cell to track transient electronic responses of the photoexcited AnPixJg2 on molecular time scales. The 525 nm laser-induced Pg-to-Pr reverse conversion exhibits a ~3 ps excited-state lifetime before reaching the conical intersection (CI) and undergoing further relaxation on the 30 ps time scale to generate a long-lived Lumi-G ground state intermediate en route to Pr. The 650 nm laser-induced Pr-to-Pg forward conversion is less efficient than reverse conversion, showing a longer-lived excited state which requires two steps with ~13 and 217 ps time constants to enter the CI region. Furthermore, using a tunable ps Raman pump with broadband Raman probe on both the Stokes and anti-Stokes sides, we collected the pre-resonance ground-state femtosecond stimulated Raman spectroscopy (GS-FSRS) data with mode assignments aided by quantum calculations. Key vibrational marker bands at ~850, 1050, 1615, and 1649 cm-1 of the Pr conformer exhibit a notable blueshift to those of the Pg conformer inside AnPixJg2, reflecting the PCB chromophore terminal D (major) and A (minor) ring twist along the primary photoswitching reaction coordinate. This integrated ultrafast spectroscopy and computational platform has the potential to elucidate photochemistry and photophysics of more CBCRs and photoactive proteins in general, providing the highly desirable mechanistic insights to facilitate the rational design of functional molecular sensors and devices.
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Affiliation(s)
- Sean R Tachibana
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Longteng Tang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Liangdong Zhu
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Yuka Takeda
- Graduate School of Integrated Science and Technology, Shizuoka University, 422-8529 Shizuoka, Japan
| | - Keiji Fushimi
- Graduate School of Integrated Science and Technology, Shizuoka University, 422-8529 Shizuoka, Japan
| | - Travis K Seevers
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Rei Narikawa
- Graduate School of Integrated Science and Technology, Shizuoka University, 422-8529 Shizuoka, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, 332-0012 Saitama, Japan
| | - Moritoshi Sato
- Graduate School of Arts and Sciences, University of Tokyo, 153-8902 Tokyo, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, 332-0012 Saitama, Japan
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States.
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12
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Batignani G, Ferrante C, Scopigno T. Accessing Excited State Molecular Vibrations by Femtosecond Stimulated Raman Spectroscopy. J Phys Chem Lett 2020; 11:7805-7813. [PMID: 32841039 PMCID: PMC7735730 DOI: 10.1021/acs.jpclett.0c01971] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/25/2020] [Indexed: 05/08/2023]
Abstract
Excited state vibrations are crucial for determining the photophysical and photochemical properties of molecular compounds. Stimulated Raman scattering can coherently stimulate and probe molecular vibrations with optical pulses, but it is generally restricted to ground state properties. Working under resonance conditions enables cross-section enhancement and selective excitation to a targeted electronic level but is hampered by an increased signal complexity due to the presence of overlapping spectral contributions. Here, we show how detailed information about ground and excited state vibrations can be disentangled by exploiting the relative time delay between Raman and probe pulses to control the excited state population, combined with a diagrammatic formalism to dissect the pathways concurring with the signal generation. The proposed method is then exploited to elucidate the vibrational properties of the ground and excited electronic states in the paradigmatic case of cresyl violet. We anticipate that the presented approach holds the potential for selective mapping of the reaction coordinates pertaining to transient electronic stages implied in photoactive compounds.
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Affiliation(s)
- Giovanni Batignani
- Dipartimento
di Fisica, Universitá di Roma “La
Sapienza”, Roma I-00185, Italy
| | - Carino Ferrante
- Dipartimento
di Fisica, Universitá di Roma “La
Sapienza”, Roma I-00185, Italy
- Center
for Life Nano Science @Sapienza, Istituto
Italiano di Tecnologia, Roma I-00161, Italy
- Graphene
Labs, Istituto Italiano di Tecnologia, Genova I-16163, Italy
| | - Tullio Scopigno
- Dipartimento
di Fisica, Universitá di Roma “La
Sapienza”, Roma I-00185, Italy
- Center
for Life Nano Science @Sapienza, Istituto
Italiano di Tecnologia, Roma I-00161, Italy
- Graphene
Labs, Istituto Italiano di Tecnologia, Genova I-16163, Italy
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13
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Dasgupta S, Herbert JM. Ab Initio Approach to Femtosecond Stimulated Raman Spectroscopy: Investigating Vibrational Modes Probed in Excited-State Relaxation of Quaterthiophenes. J Phys Chem A 2020; 124:6356-6362. [PMID: 32662999 DOI: 10.1021/acs.jpca.0c06307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Femtosecond stimulated Raman spectroscopy (FSRS) is an ultrafast pump-probe technique designed to elucidate excited-state molecular dynamics by means of vibrational spectroscopy. We present a first-principles protocol for the simulation of FSRS that integrates ab initio molecular dynamics with computational resonance Raman spectroscopy. Theoretical calculations can monitor the time-dependent evolution of specific vibrational modes and thus provide insight into the nature of the motion responsible for the experimental FSRS signal, and we apply this technique to study quaterthiophene derivatives. The S1 state of two different quaterthiophene derivatives relaxes via in-phase and out-of-phase stretching modes whose frequencies are coupled to the dihedral backbone angle, such that the spectral evolution reflects the excited-state relaxation toward a planar conformation. The simulated spectra aid in confirming the experimental assignment of the vibrational modes that are probed in the existing FSRS experiments on quaterthiophenes.
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Affiliation(s)
- Saswata Dasgupta
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - John M Herbert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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14
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Khalili K, Inhester L, Arnold C, Gertsen AS, Andreasen JW, Santra R. Simulation of time-resolved x-ray absorption spectroscopy of ultrafast dynamics in particle-hole-excited 4-(2-thienyl)-2,1,3-benzothiadiazole. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:044101. [PMID: 32665964 PMCID: PMC7340508 DOI: 10.1063/4.0000016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/15/2020] [Indexed: 06/01/2023]
Abstract
To date, alternating co-polymers based on electron-rich and electron-poor units are the most attractive materials to control functionality of organic semiconductor layers in which ultrafast excited-state processes play a key role. We present a computational study of the photoinduced excited-state dynamics of the 4-(2-thienyl)-2,1,3-benzothiadiazole (BT-1T) molecule, which is a common building block in the backbone of π-conjugated polymers used for organic electronics. In contrast to homo-polymer materials, such as oligothiophene, BT-1T has two non-identical units, namely, thiophene and benzothiadiazole, making it attractive for intramolecular charge transfer studies. To gain a thorough understanding of the coupling of excited-state dynamics with nuclear motion, we consider a scenario based on femtosecond time-resolved x-ray absorption spectroscopy using an x-ray free-electron laser in combination with a synchronized ultraviolet femtosecond laser. Using Tully's fewest switches surface hopping approach in combination with excited-state calculations at the level of configuration interaction singles, we calculate the gas-phase x-ray absorption spectrum at the carbon and nitrogen K edges as a function of time after excitation to the lowest electronically excited state. The results of our time-resolved calculations exhibit the charge transfer driven by non-Born-Oppenheimer physics from the benzothiadiazole to thiophene units during relaxation to the ground state. Furthermore, our ab initio molecular dynamics simulations indicate that the excited-state relaxation processes involve bond elongation in the benzothiadiazole unit as well as thiophene ring puckering at a time scale of 100 fs. We show that these dynamical trends can be identified from the time-dependent x-ray absorption spectrum.
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Affiliation(s)
- Khadijeh Khalili
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej 310, 2800 Kgs. Lyngby, Denmark
| | | | | | - Anders S. Gertsen
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej 310, 2800 Kgs. Lyngby, Denmark
| | - Jens Wenzel Andreasen
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej 310, 2800 Kgs. Lyngby, Denmark
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15
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Barclay MS, Elles CG, Caricato M. On the Discrepancy between Experimental and Calculated Raman Intensities for Conjugated Phenyl and Thiophene Derivatives. J Phys Chem A 2020; 124:4678-4689. [PMID: 32392419 DOI: 10.1021/acs.jpca.0c00363] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Compared with experimental spectra, calculations for conjugated phenyl and thiophene oligomers tend to overestimate the ground state Raman intensities of higher-frequency vibrations (1200-1800 cm-1) relative to the intensities at lower frequencies (<1200 cm-1). The discrepancy was observed in previous benchmarking work that examined the method dependence of the calculated Raman spectra for a series of aromatic molecules. This paper further investigates the nature of the discrepancy by examining the role of anharmonic corrections and the dependence of the calculated Raman spectra on the inter-ring torsion angle for the representative molecules biphenyl (BP), 2-phenylthiophene (PT), and 2,2'-bithiophene (BT). Perturbative anharmonic corrections to the spectra calculated using density functional theory (DFT) provide only slightly better agreement with experiment. On the other hand, calculations at larger torsion angles give up to 30% improvement in the relative Raman intensities compared with the spectra calculated at the optimized geometries. The torsion-angle dependence of the Raman intensities is most pronounced for delocalized C-C and C-S stretching modes, and less pronounced for bending and ring distortion modes that do not involve inter-ring stretching. Higher-level calculations using the coupled cluster with single, double, and perturbative triple excitations [CCSD(T)] method indicate that DFT underestimates the energy barrier for torsion isomerization at small angles, and it overestimates the barriers at large angles, thus predicting minimum geometries at torsion angles that are too small. Therefore, the results suggest that the discrepancy in relative Raman intensities may be related to an overestimation of inter-ring conjugation by DFT, which also tends to favor geometries that are too planar.
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Affiliation(s)
- Matthew S Barclay
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Christopher G Elles
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Marco Caricato
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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16
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Andrikopoulos PC, Liu Y, Picchiotti A, Lenngren N, Kloz M, Chaudhari AS, Precek M, Rebarz M, Andreasson J, Hajdu J, Schneider B, Fuertes G. Femtosecond-to-nanosecond dynamics of flavin mononucleotide monitored by stimulated Raman spectroscopy and simulations. Phys Chem Chem Phys 2020; 22:6538-6552. [PMID: 31994556 DOI: 10.1039/c9cp04918e] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Flavin mononucleotide (FMN) belongs to the large family of flavins, ubiquitous yellow-coloured biological chromophores that contain an isoalloxazine ring system. As a cofactor in flavoproteins, it is found in various enzymes and photosensory receptors, like those featuring the light-oxygen-voltage (LOV) domain. The photocycle of FMN is triggered by blue light and proceeds via a cascade of intermediate states. In this work, we have studied isolated FMN in an aqueous solution in order to elucidate the intrinsic electronic and vibrational changes of the chromophore upon excitation. The ultrafast transitions of excited FMN were monitored through the joint use of femtosecond stimulated Raman spectroscopy (FSRS) and transient absorption spectroscopy encompassing a time window between 0 ps and 6 ns with 50 fs time resolution. Global analysis of the obtained transient visible absorption and transient Raman spectra in combination with extensive quantum chemistry calculations identified unambiguously the singlet and triplet FMN populations and addressed solvent dynamics effects. The good agreement between the experimental and theoretical spectra facilitated the assignment of electronic transitions and vibrations. Our results represent the first steps towards more complex experiments aimed at tracking structural changes of FMN embedded in light-inducible proteins upon photoexcitation.
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Affiliation(s)
- Prokopis C Andrikopoulos
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, CZ-252 50 Vestec, Czech Republic.
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17
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Barclay MS, Elles CG, Caricato M. Benchmark Study of Ground-State Raman Spectra in Conjugated Molecules. J Chem Theory Comput 2019; 16:612-620. [DOI: 10.1021/acs.jctc.9b00960] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew S. Barclay
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Christopher G. Elles
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Marco Caricato
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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18
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Barclay MS, Caricato M, Elles CG. Femtosecond Stimulated Raman Scattering from Triplet Electronic States: Experimental and Theoretical Study of Resonance Enhancements. J Phys Chem A 2019; 123:7720-7732. [DOI: 10.1021/acs.jpca.9b05955] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew S. Barclay
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Marco Caricato
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Christopher G. Elles
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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19
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Quincy TJ, Barclay MS, Caricato M, Elles CG. Probing Dynamics in Higher-Lying Electronic States with Resonance-Enhanced Femtosecond Stimulated Raman Spectroscopy. J Phys Chem A 2018; 122:8308-8319. [PMID: 30256101 DOI: 10.1021/acs.jpca.8b07855] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Femtosecond stimulated Raman scattering (FSRS) measurements typically probe the structural dynamics of a molecule in the first electronically excited state, S1. While these measurements often rely on an electronic resonance condition to increase signal strength or enhance species selectivity, the effects of the resonance condition are usually neglected. However, mode-specific enhancements of the vibrational transitions in an FSRS spectrum contain detailed information about the resonant (upper) electronic state. Analogous to ground-state resonance Raman spectroscopy, the relative intensities of the Raman bands reveal displacements of the upper potential energy surface due to changes in the bonding pattern upon S n ← S1 electronic excitation, and therefore provide a sensitive probe of the ultrafast dynamics in the higher-lying state, S n. Raman gain profiles from the wavelength-dependent FSRS spectrum of the model compound 2,5-diphenylthiophene (DPT) reveal several modes with large displacement in the upper potential energy surface, including strong enhancement of a delocalized C-S-C stretching and ring deformation mode. The experimental results provide a benchmark for comparison with calculated spectra using time-dependent density functional theory (TD-DFT) and equation-of-motion coupled-cluster theory with single and double excitations (EOM-CCSD), where the calculations are based on the time-dependent formalism for resonance Raman spectroscopy. The simulated spectra are obtained from S1-S n transition strengths and the energy gradients of the upper (S n) potential energy surfaces along the S1 normal mode coordinates. The experimental results provide a stringent test of the computational approach, and indicate important limitations based on the level of theory and basis set. This work provides a foundation for making more accurate assignments of resonance-enhanced excited-state Raman spectra, as well as extracting novel information about higher-lying excited states in the transient absorption spectrum of a molecule.
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Affiliation(s)
- Timothy J Quincy
- Department of Chemistry , University of Kansas , Lawrence , Kansas 66045 , United States
| | - Matthew S Barclay
- Department of Chemistry , University of Kansas , Lawrence , Kansas 66045 , United States
| | - Marco Caricato
- Department of Chemistry , University of Kansas , Lawrence , Kansas 66045 , United States
| | - Christopher G Elles
- Department of Chemistry , University of Kansas , Lawrence , Kansas 66045 , United States
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20
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Multidimensional Vibrational Coherence Spectroscopy. Top Curr Chem (Cham) 2018; 376:35. [DOI: 10.1007/s41061-018-0213-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/31/2018] [Indexed: 10/28/2022]
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21
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Schnappinger T, Marazzi M, Mai S, Monari A, González L, de Vivie-Riedle R. Intersystem Crossing as a Key Component of the Nonadiabatic Relaxation Dynamics of Bithiophene and Terthiophene. J Chem Theory Comput 2018; 14:4530-4540. [DOI: 10.1021/acs.jctc.8b00492] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thomas Schnappinger
- Department of Chemistry, Ludwig-Maximilians-Universität München, D-81377 München, Germany
| | - Marco Marazzi
- Departamento de Química, Centro de Investigación en Síntesis Química (CISQ), Universidad de La Rioja, 26006 Logroño, Spain
- Université
de Lorraine and CNRS, LPCT UMR 7019, F-54000 Nancy, France
| | - Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Antonio Monari
- Université
de Lorraine and CNRS, LPCT UMR 7019, F-54000 Nancy, France
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Regina de Vivie-Riedle
- Department of Chemistry, Ludwig-Maximilians-Universität München, D-81377 München, Germany
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22
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Hloušková Z, Tydlitát J, Kong M, Pytela O, Mikysek T, Klikar M, Almonasy N, Dvořák M, Jiang Z, Růžička A, Bureš F. Structure-Catalytic Activity in a Series of Push-Pull Dicyanopyrazine/Dicyanoimidazole Photoredox Catalysts. ChemistrySelect 2018. [DOI: 10.1002/slct.201800719] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zuzana Hloušková
- Institute of Organic Chemistry and Technology; Faculty of Chemical Technology, University of Pardubice; Studentská 573, Pardubice 53210 Czech Republic
| | - Jiří Tydlitát
- Institute of Organic Chemistry and Technology; Faculty of Chemical Technology, University of Pardubice; Studentská 573, Pardubice 53210 Czech Republic
| | - Manman Kong
- Key Laboratory of Natural Medicine and Immuno-Engineering of Henan Province; Henan University; Kaifeng Henan 475004, People's Republic of China
| | - Oldřich Pytela
- Institute of Organic Chemistry and Technology; Faculty of Chemical Technology, University of Pardubice; Studentská 573, Pardubice 53210 Czech Republic
| | - Tomáš Mikysek
- Department of Analytical Chemistry; Faculty of Chemical Technology, University of Pardubice; Studentská 573 Pardubice 53210 Czech Republic
| | - Milan Klikar
- Institute of Organic Chemistry and Technology; Faculty of Chemical Technology, University of Pardubice; Studentská 573, Pardubice 53210 Czech Republic
| | - Numan Almonasy
- Institute of Organic Chemistry and Technology; Faculty of Chemical Technology, University of Pardubice; Studentská 573, Pardubice 53210 Czech Republic
| | - Miroslav Dvořák
- Department of Physical Electronics; Faculty of Nuclear Sciences and Physical Engineering; Czech Technical University in Prague; V Holešovičkách 2 CZ-180 00 Prague, Czech Republic
| | - Zhiyong Jiang
- Key Laboratory of Natural Medicine and Immuno-Engineering of Henan Province; Henan University; Kaifeng Henan 475004, People's Republic of China
| | - Aleš Růžička
- Department of General and Inorganic Chemistry; Faculty of Chemical Technology; University of Pardubice; Studentská 573, Pardubice 53210 Czech Republic
| | - Filip Bureš
- Institute of Organic Chemistry and Technology; Faculty of Chemical Technology, University of Pardubice; Studentská 573, Pardubice 53210 Czech Republic
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