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
Soft Photopolymerizations Initiated by Dye-Sensitized Formation of NHC-Boryl Radicals under Visible Light
Sofia Telitel,Stéphane Schweizer,Fabrice Morlet-Savary,Bernadette Graff,Théophile Tschamber,Nicolas Blanchard,Jean Pierre Fouassier,Moreno Lelli,Emmanuel Lacôte,Jacques Lalevée +9 more
TL;DR: In this article, a procedure for the production of N-heterocyclic carbene-boryl radicals (NHC-BH2•) upon visible light irradiation under soft conditions is presented.
Journal ArticleDOI
Correction: Room-temperature phosphorescent γ-cyclodextrin-cucurbit[6]uril-cowheeled [4]rotaxanes for specific sensing of tryptophan
TL;DR: The strong green RTP was quenched exclusively by Trp while no RTP quenching was observed with other major physiological amino acids or with the Trp-containing protein HSA, demonstrating a highly specific sensing of free Trp.
Journal ArticleDOI
Long wavelength photosensitizers in photoinitiated cationic polymerization: The effect of quinoxaline derivatives on photopolymerization
TL;DR: In this article, the use of functionalized quinoxaline derivatives as photosensitizers for diaryliodonium salt photoinitiators was described, and the polymerization was monitored by optical pyrometry (OP).
Journal ArticleDOI
A turn-on PET fluorescence sensor for imaging Cu2+ in living cells
Guangjie He,Xiuwen Zhao,Xiaolin Zhang,Hongjun Fan,Shuo Wu,Huaqiang Li,Cheng He,Chunying Duan +7 more
TL;DR: One of the brightest Cu 2+-binding sensors in aqueous media was achieved and could be used for the detection of Cu2+ in living cells.
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.