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
Antimony porphyrin complexes as visible-light driven photocatalyst
TL;DR: In this article, the physicochemical properties and the photocatalytic application of antimony porphyrin complexes (SbTPP) were reviewed from the viewpoint of electron and energy transfer quenching processes.
Journal ArticleDOI
Fluorescent PET(Photoinduced Electron Transfer) reagents for thiols
TL;DR: Michael addition of thiois to an electron deficient alkene functional group in reagents (1)-(3) give rise to fluorescence quantum yield enhancements in the absence of the thiol.
Journal ArticleDOI
Supramolecular design of photocurrent-generating devices using fullerenes aimed at modelling artificial photosynthesis
Journal ArticleDOI
Photophysical Characterization of a Ruthenium(II) Tris(2,2′-bipyridine)-Doped Zirconium UiO-67 Metal–Organic Framework
William A. Maza,Amanda J. Morris +1 more
TL;DR: The photophysical properties of ruthenium(II) tris(5,5′-dicarboxy-2,2′-bipyridine), RuDCBPY-UiO67, doped into the metal organic framework of Zr6O4(OH)4(BPDC)6 as mentioned in this paper, are presented as a function of the degree of Ru DCBPY doping.
Journal ArticleDOI
Oxygen imaging of living cells and tissues using luminescent molecular probes
TL;DR: Current knowledge regarding the mechanism of phosphorescence quenching of metal complexes by oxygen is described in relation to the oxygen sensitivity of the probes, and recent advances in optical oxygen probes and detection techniques for intracellular and tissue oxygen measurements are reviewed, emphasizing the usefulness of chemical modifications for improving probe properties.
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.