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Juneau A, Hope TO, Malenfant J, Mesko M, McNeill J, Frenette M. Methods to Predict Potential Reagents in Iridium-Based Photoredox Catalysis Calibrated with Stern–Volmer Quenching Rate Constants. ACS Catal 2022. [DOI: 10.1021/acscatal.1c04740] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Antoine Juneau
- Department of Chemistry and NanoQAM, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada
| | - Taylor O. Hope
- Department of Chemistry and NanoQAM, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada
| | - Jason Malenfant
- Department of Chemistry and NanoQAM, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada
| | - Mihai Mesko
- Department of Chemistry and NanoQAM, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada
| | - Jacob McNeill
- Department of Chemistry and NanoQAM, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada
| | - Mathieu Frenette
- Department of Chemistry and NanoQAM, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada
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2
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Matsumoto S, Abe H, Akazome M. Fluorescence of Diimidazo[1,2-a:2′,1′-c]quinoxalinium Salts Under Various Conditions. J Org Chem 2013; 78:2397-404. [DOI: 10.1021/jo302531g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Shoji Matsumoto
- Department
of Applied Chemistry and Biotechnology,
Graduate School of Engineering, Chiba University, 1-33 Yayoicho, Inageku, Chiba 263-8522, Japan
| | - Hajime Abe
- Department
of Applied Chemistry and Biotechnology,
Graduate School of Engineering, Chiba University, 1-33 Yayoicho, Inageku, Chiba 263-8522, Japan
| | - Motohiro Akazome
- Department
of Applied Chemistry and Biotechnology,
Graduate School of Engineering, Chiba University, 1-33 Yayoicho, Inageku, Chiba 263-8522, Japan
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Kumbhakar M, Nath S, Rath MC, Mukherjee T, Pal H. Electron Transfer Interaction of Dihydroxyquinones with Amine Quenchers: Dependence of the Quenching Kinetics on the Aliphatic and Aromatic Nature of the Amine Donors¶. Photochem Photobiol 2011. [DOI: 10.1111/j.1751-1097.2004.tb09850.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Anbazhagan V, Kathiravan A, Jhonsi MA, Renganathan R. Fluorescence Quenching Study on Electron Transfer from Certain Amines to Excited State Triphenylpyrylium Ion (TPP+). ACTA ACUST UNITED AC 2009. [DOI: 10.1524/zpch.2007.221.7.929] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The fluorescence quenching of excited singlet state of 2,4,6-triphenylpyrylium tetrafluoroborate (TPPBF4 or TPP+), a very good electron acceptor by amines were investigated in a acetonitrile solution using steady state technique. The bimolecular quenching rate constants lie in the range 2.11–10.26 × 1010 M-1 s-1. The driving force (ΔGet) for electron transfer process was calculated from the oxidation potential of amines and the reduction potential of TPP+. The observed k
q values correlated well with the driving force for the electron transfer reactions. Aromatic amines show higher k
q than aliphatic amines. From the oxidation potential of amines and the quenching rate constant values, a mechanism involving photoinduced electron transfer from amines to excited state TPP is suggested.
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Singh PK, Nath S, Bhasikuttan AC, Kumbhakar M, Mohanty J, Sarkar SK, Mukherjee T, Pal H. Effect of donor orientation on ultrafast intermolecular electron transfer in coumarin-amine systems. J Chem Phys 2008; 129:114504. [DOI: 10.1063/1.2975192] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Rosspeintner A, Kattnig DR, Angulo G, Landgraf S, Grampp G. The Rehm-Weller experiment in view of distant electron transfer. Chemistry 2008; 14:6213-21. [PMID: 18506871 DOI: 10.1002/chem.200701841] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The driving-force dependence of bimolecular fluorescence quenching by electron transfer in solution, the Rehm-Weller experiment, is revisited. One of the three long-standing unsolved questions about the features of this experiment is carefully analysed here, that is, is there a diffusional plateau? New experimental quenching rates are compiled for a single electron donor, 2,5-bis(dimethylamino)-1,3-benzenedicarbonitrile, and eighteen electron acceptors in acetonitrile. The data are analysed in the framework of differential encounter theory by using an extended version of the Marcus theory to model the intrinsic electron-transfer step. Only by including the hydrodynamic effect and the solvent structure can the experimental findings be well modelled. The diffusional control region, the "plateau", reveals the inherent distance dependence of the reaction, which is shown to be a general feature of electron transfer in solution.
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Affiliation(s)
- A Rosspeintner
- Graz University of Technology, Technikerstrasse 4/I, 8010 Graz, Austria
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Alberti A, Galasso V, Kovac B, Modelli A, Pichierri F. Probing the molecular and electronic structure of capsaicin: a spectroscopic and quantum mechanical study. J Phys Chem A 2008; 112:5700-11. [PMID: 18507451 DOI: 10.1021/jp801890g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The conformational preferences of capsaicin were investigated by using the hybrid meta density functional theory (DFT) method MPWB1K. Its flexible, pendant side chain allows for a multitude of conformations only slightly different in energy. The distinctive vibrational features of the most stable conformers were characterized. To elucidate the most favorable reaction sites of capsaicin for radical scavenging, various homolytic bond-dissociation energies were also calculated. Of the possible radical intermediates, the allyl and benzyl radicals are energetically preferred. The filled and empty electronic structures of capsaicin were investigated by exploiting the photoelectron and electron-transmission spectra also of reference molecules and suitable quantum-mechanical calculations. On this basis, a reliable pattern of the vertical ionization energies and electron-attachment energies of capsaicin was proposed. The frontier pi molecular orbitals are concentrated over the vanillyl moiety, with a modest influence of the amidic-aliphatic chain. The (negative) first vertical electron affinity is predicted to be similar to that of benzene. The absorption spectrum of capsaicin and its change by conversion into a phenolic deprotonated anion (modest bathochromic displacement) or a phenoxyl neutral radical (from colorless to red) were interpreted with time-dependent DFT calculations. ESR measurements following chemical or electrochemical reduction of capsaicin did not lead to detection of the corresponding radical anion. The spectra show fragmentation of the original molecule and formation of a variety of radical species which are believed to have a semiquinonic structure.
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Affiliation(s)
- A Alberti
- ISOF, Area della Ricerca del CNR, Via Gobetti 101, I-40129 Bologna, Italy
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8
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Bimolecular electron transfer reactions in coumarin–amine systems: Donor–acceptor orientational effect on diffusion-controlled reaction rates. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2007.07.042] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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9
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Kumbhakar M, Nath S, Mukherjee T, Pal H. Effect of micellar environment on Marcus correlation curves for photoinduced bimolecular electron transfer reactions. J Chem Phys 2005; 123:34705. [PMID: 16080753 DOI: 10.1063/1.1953579] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Photoinduced electron transfer (ET) between coumarin dyes and aromatic amine has been investigated in two cationic micelles, namely, cetyltrimethyl ammonium bromide (CTAB) and dodecyltrimethyl ammonium bromide (DTAB), and the results have been compared with those observed earlier in sodium dodecyl sulphate (SDS) and triton-X-100 (TX-100) micelles for similar donor-acceptor pairs. Due to a reasonably high effective concentration of the amines in the micellar Stern layer, the steady-state fluorescence results show significant static quenching. In the time-resolved (TR) measurements with subnanosecond time resolution, contribution from static quenching is avoided. Correlations of the dynamic quenching constants (k(q) (TR)), as estimated from the TR measurements, show the typical bell-shaped curves with the free-energy changes (DeltaG(0)) of the ET reactions, as predicted by the Marcus outersphere ET theory. Comparing present results with those obtained earlier for similar coumarin-amine systems in SDS and TX-100 micelles, it is seen that the inversion in the present micelles occurs at an exergonicity (-DeltaG(0)> approximately 1.2-1.3 eV) much higher than that observed in SDS and TX-100 micelles (-DeltaG(0)> approximately 0.7 eV), which has been rationalized based on the relative propensities of the ET and solvation rates in different micelles. In CTAB and DTAB micelles, the k(q) (TR) values are lower than the solvation rates, which result in the full contribution of the solvent reorganization energy (lambda(s)) towards the activation barrier for the ET reaction. Contrary to this, in SDS and TX-100 micelles, k(q) (TR) values are either higher or comparable with the solvation rates, causing only a partial contribution of lambda(s) in these cases. Thus, Marcus inversion in present cationic micelles is inferred to be the true inversion, whereas that in the anionic SDS and neutral TX-100 micelles are understood to be the apparent inversion, as envisaged from two-dimensional ET theory.
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Affiliation(s)
- Manoj Kumbhakar
- Radiation Chemistry and Chemical Dynamics Division, Bhabha Atomic Research Centre, Mumbai, India
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10
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Kumbhakar M, Mukherjee T, Pal H. Marcus inversion in electron transfer reactions between coumarins and aliphatic amines in TX-100 micellar solution. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.05.048] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Kumbhakar M, Nath S, Rath MC, Mukherjee T, Pal H. Electron Transfer Interaction of Dihydroxyquinones with Amine Quenchers: Dependence of the Quenching Kinetics on the Aliphatic and Aromatic Nature of the Amine Donors¶. Photochem Photobiol 2004. [DOI: 10.1562/0031-8655(2004)79<1:etiodw>2.0.co;2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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12
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Onoda M, Uchiyama S, Santa T, Imai K. A photoinduced electron-transfer reagent for peroxyacetic acid, 4-ethylthioacetylamino-7-phenylsulfonyl-2,1,3-benzoxadiazole, based on the method for predicting the fluorescence quantum yields. Anal Chem 2002; 74:4089-96. [PMID: 12199579 DOI: 10.1021/ac0201225] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To develop new photoinduced electron-transfer (PET) reagents, we established a method for predicting the fluorescence quantum yields (phi) of the benzofurazan compounds bearing an aliphatic substituent group having an n-electron. The PET process occurred sufficiently to reduce the phi values in the benzofurazan compounds bearing an aliphatic moiety, which had a high quenching ability. The quenching ability was estimated by the molecular orbital calculation and Stern-Volmer plotting. The phi values of the benzofurazan compounds could be controlled by changing the quenching ability of a substituent group. We succeeded in designing a PET reagent for peroxyacetic acid (PAA), 4-ethylthioacetylamino-7-phenylsulfonyl-2,1,3-benzoxadiazole (EPB), using the established method for predicting the phi values. EPB and its oxidized derivative were separated by reversed-phase HPLC and fluorometrically detected at 479 nm with excitation at 362 nm. The attained detection limit for PAA was 105 fmol (S/N = 3) and the cross-reactivity toward hydrogen peroxide was very low, indicating EPB is a highly sensitive and selective reagent for PAA.
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Affiliation(s)
- Maki Onoda
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
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13
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Nicolet O, Vauthey E. Ultrafast Nonequilibrium Charge Recombination Dynamics of Excited Donor−Acceptor Complexes. J Phys Chem A 2002. [DOI: 10.1021/jp025542c] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Vauthey E. Direct Measurements of the Charge-Recombination Dynamics of Geminate Ion Pairs Formed upon Electron-Transfer Quenching at High Donor Concentration. J Phys Chem A 2000. [DOI: 10.1021/jp0023260] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Eric Vauthey
- Institut de Chimie-Physique de l'Université de Fribourg, Pérolles, CH-1700 Fribourg, Switzerland
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15
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Pischel U, Zhang X, Hellrung B, Haselbach E, Muller PA, Nau WM. Fluorescence Quenching of n,π*-Excited Azoalkanes by Amines: What Is a Sterically Hindered Amine? J Am Chem Soc 2000. [DOI: 10.1021/ja992508b] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Uwe Pischel
- Contribution from the Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, and the Institute of Physical Chemistry, University of Fribourg, Pérolles, CH-1700 Fribourg, Switzerland
| | - Xiangyang Zhang
- Contribution from the Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, and the Institute of Physical Chemistry, University of Fribourg, Pérolles, CH-1700 Fribourg, Switzerland
| | - Bruno Hellrung
- Contribution from the Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, and the Institute of Physical Chemistry, University of Fribourg, Pérolles, CH-1700 Fribourg, Switzerland
| | - Edwin Haselbach
- Contribution from the Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, and the Institute of Physical Chemistry, University of Fribourg, Pérolles, CH-1700 Fribourg, Switzerland
| | - Pierre-Alain Muller
- Contribution from the Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, and the Institute of Physical Chemistry, University of Fribourg, Pérolles, CH-1700 Fribourg, Switzerland
| | - Werner M. Nau
- Contribution from the Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, and the Institute of Physical Chemistry, University of Fribourg, Pérolles, CH-1700 Fribourg, Switzerland
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