Journal ArticleDOI
Kinetics of Fluorescence Quenching by Electron and H‐Atom Transfer
Dieter Rehm,Albert Weller +1 more
TLDR
In this article, the rate constants of 60 typical electron donor-acceptor systems have been measured in de-oxygenated acetonitrile and are shown to be correlated with the free enthalpy change, ΔG23, involved in the actual electron transfer process.Abstract:
Fluorescence quenching rate constants, kq, ranging from 106 to 2 × 1010 M−1 sec−1, of more than 60 typical electron donor-acceptor systems have been measured in de-oxygenated acetonitrile and are shown to be correlated with the free enthalpy change, ΔG23, involved in the actual electron transfer process
in the encounter complex and varying between + 5 and −60 kcal/mole. The correlation which is based on the mechanism of adiabatic outer-sphere electron transfer requires ΔG≠23, the activation free enthalpy of this process to be a monotonous function of ΔG23 and allows the calculation of rate constants of electron transfer quenching from spectroscopic and electrochemical data.
A detailed study of some systems where the calculated quenching constants differ from the experimental ones by several orders of magnitude revealed that the quenching mechanism operative in these cases was hydrogen-atom rather than electron transfer.
The conditions under which these different mechanisms apply and their consequences are discussed.read more
Citations
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Journal ArticleDOI
Synthesis and photophysics of a porphyrin–fullerene dyad assembled through Watson–Crick hydrogen bonding
Jonathan L. Sessler,Janarthanan Jayawickramarajah,Andreas Gouloumis,Tomás Torres,Dirk M. Guldi,Stephen Maldonado,Keith J. Stevenson +6 more
TL;DR: A novel porphyrin-fullerene dyad assembled through Watson-Crick hydrogen bonds is described; this system undergoes photoinduced electron transfer upon irradiation with visible light to produce a charge separated state that is substantially longer lived than that of previous dyads of this type.
Journal ArticleDOI
Ordered and oriented supramolecular n/p-heterojunction surface architectures: completion of the primary color collection
Ravuri S. K. Kishore,Oksana Kel,Natalie Banerji,Daniel Emery,Guillaume Bollot,Jiri Mareda,Alberto Gomez-Casado,Pascal Jonkheijm,Jurriaan Huskens,Plinio Maroni,Michal Borkovec,Eric Vauthey,Naomi Sakai,Stefan Matile +13 more
TL;DR: The direct comparison of zipper and LBL assemblies reveals that yellow zippers generate more photocurrent than blue zippers as well as LBL photosystems, and found characteristics, such as significant critical thickness, strong photocurrents, large fill factors, and, according to AFM images, smooth surfaces, are important for optoelectronic performance and support the existence of highly ordered architectures.
Journal ArticleDOI
Enhanced Electron‐Transfer Properties of Cofacial Porphyrin Dimers through π–π Interactions
TL;DR: The enhanced electron-transfer properties of cofacial porphyrin dimers, in relation with the important role of the special pair in the photosynthetic reaction center, result from the smaller reorganization energy (lambda) together with the larger driving force of the photoinduced electron transfer due to the pi-electron delocalization in the dimer radical cations.
Journal ArticleDOI
Synthesis of novel phthalocyanine-tetrathiafulvalene hybrids; intramolecular fluorescence quenching related to molecular geometry.
TL;DR: The potential for rapid electrochemical switching of the phthalocyanine fluorescence by oxidation of the appended tetrathiafulvalene units is explored and the degree of this fluorescence quenching to be related to the intramolecular spacing is explored.
Journal ArticleDOI
Carbazole Scaffold Based Photoinitiator/Photoredox Catalysts: Toward New High Performance Photoinitiating Systems and Application in LED Projector 3D Printing Resins
Assi Al Mousawi,Assi Al Mousawi,Frédéric Dumur,Patxi Garra,Joumana Toufaily,Tayssir Hamieh,Bernadette Graff,Didier Gigmes,Jean Pierre Fouassier,Jacques Lalevée +9 more
TL;DR: In this paper, four new carbazole derivatives (C1-C4) are synthesized and proposed as high performance visible light photoinitiators/photoredox catalysts for both the free radical polymerization (FRP) of (meth)acrylates and the cationic polymerization of epoxides upon visible light exposure using light-emitting diodes (LEDs).
References
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Journal ArticleDOI
On the Theory of Oxidation‐Reduction Reactions Involving Electron Transfer. I
TL;DR: In this paper, a mechanism for electron transfer reactions is described, in which there is very little spatial overlap of the electronic orbitals of the two reacting molecules in the activated complex, and a quantitative theory of the rates of oxidation reduction reactions involving electron transfer in solution is presented.
Journal ArticleDOI
Chemical and Electrochemical Electron-Transfer Theory
TL;DR: In this article, a review of electron transfer reactions is presented, focusing on the absence of bond rupture in the reaction step, which is a unique feature of purely electron-transfer reactions.
Journal ArticleDOI
Polarographic Oxidation Potentials of Aromatic Compounds
E. S. Pysh,N. C. Yang +1 more
TL;DR: In this article, the oxidation half-wave potentials of fifty-three organic compounds were determined in acetonitrile at a rotating Pt electrode, and these values were correlated with ionization potentials, with interaction energies of charge transfer complexes with trinitrofluorenone, with Huckel coefficients of the resonance integral in the expression for the highest occupied molecular orbital energy level, and with pabsorption band spectra.
Journal ArticleDOI
Electron-transfer and complex formation in the excited state
TL;DR: In this paper, a broad structureless emission band about 5000 cm1 was observed to increase with increasing electron donor concentration at the expense of the fluorescence intensity of the hydrocarbon, thereby following the same Stern-Volmer-type relation as does the well known excimer fluorescence.