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
Stilbene radical anions in the excited doublet state
TL;DR: In this paper, the second excited doublet state generated by a pulse radiolysis−laser flash photolysis combined method undergo unimolecular isomerization from c-St•- to t-st•-, photoelectron ejection, and electron transfer to biphenyl added as a quencher.
Journal ArticleDOI
Efficient photoinduced electron transfer between C60 and tetrathiafulvalenes studied by nanosecond laser photolysis
TL;DR: In this paper, the transient absorption bands of the C 60 triplet (T C 60 ∗ ) observed in polar and non-polar solvents and their mixtures were investigated by nanosecond laser photolysis/transient absorption spectroscopy in the visible and near-IR regions.
Journal ArticleDOI
Molecular Dynamics and DFT Studies of Intermolecular Hydrogen Bonds between Bifunctional Heteroazaaromatic Molecules and Hydroxylic Solvents
TL;DR: In this paper, molecular dynamics and ab initio/density functional theory (DFT) studies were performed for alcohol and water complexes of 1H-pyrrolo[3,2-h]quinoline (PQ), 2-(2‘pyridyl)indole (PyIn-2), and 7-azaindole (7AI).
Journal ArticleDOI
Comparison of photoinduced electron transfer reactions of aromatic carbonyl vs. cyano compounds with electron donors in condensed phase:the importance
TL;DR: In this article, photo-induced electron transfer reactions in acetonitrile with bensopheneone, anthraquinone, 9-cyanoanthracene and 9,10-dicyanoanthracene as electron acceptors, and with 1,4-diasabicyclo[2,2, 2]octane and N,N-dimethylaniline as electron donors have been studied with ns-laser flash photolysis and fluorescence quenching measurements.
Journal ArticleDOI
Photoinduced Electron Transfer in Platinum(II) Terpyridinyl Acetylide Complexes Connected to a Porphyrin Unit
Cyrille Monnereau,Julio Gómez,Errol Blart,Fabrice Odobel,Staffan Wallin,Anna Fallberg,Leif Hammarström +6 more
TL;DR: A series of six new dyads consisting of a zinc or magnesium porphyrin appended to a platinum terpyridine acetylide complex via a para-phenylene bisacetylene spacer underscore the potential of the para- Phenylene bis acetylene bridge to mediate a rapid electron transfer over a long donor-acceptor distance.
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.