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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Book ChapterDOI
Fundamental concepts of photoinduced electron transfer
TL;DR: In this paper, the energy and dynamics of photo-induced electron transfer (PET) are explored on the basis of the classical Marcus-Hush theory and nonclassical, quantum mechanical theories.
Journal ArticleDOI
Bimolecular electron transfer in ionic liquids: are reaction rates anomalously high?
TL;DR: A more complete analysis of the quenching data using a model combining approximate solution of the spherically symmetric diffusion equation with a Marcus-type description of electron transfer reveals the reasons for frequent observation of k(q) ≫ k(D).
Journal ArticleDOI
Bioinspired High-Potential Porphyrin Photoanodes
Gary F. Moore,Gary F. Moore,Steven J. Konezny,Hee Eun Song,Rebecca L. Milot,James D. Blakemore,Minjoo Lawrence Lee,Victor S. Batista,Charles A. Schmuttenmaer,Robert H. Crabtree,Gary W. Brudvig +10 more
TL;DR: In this article, a selection of high-potential porphyrin photoanodes (HPPPs) for use in photoelectrochemical cells (PECs) was reported.
Journal ArticleDOI
Triplet Acetylenes as Synthetic Equivalents of 1,2-Bicarbenes: Phantom n,π* State Controls Reactivity in Triplet Photocycloaddition
Tarek A. Zeidan,Serguei V. Kovalenko,Mariappan Manoharan,Ronald J. Clark,Ion Ghiviriga,Igor V. Alabugin +5 more
TL;DR: Diaryl acetylenes, in which one of the aryl groups is either a pyridine or a pyrazine, undergo efficient triplet state photocycloaddition to 1,4-cyclohexadiene with formation of 1,5-diaryl substituted tetracyclo (homoquadricyclanes).
Journal ArticleDOI
Azahelicenes as visible light photoinitiators for cationic and radical polymerization: Preparation of photoluminescent polymers and use in high performance LED projector 3D printing resins
Assi Al Mousawi,Assi Al Mousawi,Frédéric Dumur,Patxi Garra,Joumana Toufaily,Tayssir Hamieh,Fabrice Goubard,Thanh-Tuân Bui,Bernadette Graff,Didier Gigmes,Jean Pierre Fouassier,Jacques Lalevée +11 more
TL;DR: In this article, novel azahelicenes (AZs) were synthesized and proposed as high performance visible light photoinitiators for both the free radical polymerization of acrylates and the cationic polymerization (CP) of epoxides upon visible light exposure using Light Emitting Diodes (LEDs) @405, @455, and @470 nm.
References
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Journal ArticleDOI
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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.
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Electron-transfer and complex formation in the excited state
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