Electron exchange rate constant

Rehm-Weller method (21) for estimating the reduction potentials of excited molecules As our homologous series of reductants, we have used the RuL3 +/ RuL32+ couples (22,23), where RuL32+ is the luminescent excited state of Rul 7 The electron exchange rate constants for these couples are very large... 

Since AF ex equals —RT ln( ex/10u M l sec. 1)> X2 can be estimated from the electron exchange rate constant kex when correction of AF ex is made for uf or when uf is small enough to be neglected. Values of AF ex have also been obtained indirectly from measurements of rate... 

Reactions of hydroquinone, catechol, and L-ascorbic acid with dicyanobis(l,10-phenan-thn>line)iion(III) were studied in dimethyl sulfoxide (DMSO). Application of the Marcus theory to the reactions of catechol and hydroquinone provided the electron exchange rate constant for the Fe(III/II) couple in DMSO. The self-exchange rate constant for the ascorbic acidAadical couple was estimated for the first time in DMSO. The one electron-oxidation process of L-ascorbic acid in an aprotic solvents such as DMSO may be completely different from that in aqueous solutions. 

The electron exchange rate constant of the iron(III) complex in DMSO was estimated from the cross reactions with hydroquinone and catechol, which was compared with the rate constant obtained electrochemically. The mechanism of the ascorbic acid oxidation reaction in DMSO is discussed based on the Marcus theory. 

Both Forster and electron exchange rate constants depend on the spectral overlap integral J between the emission spectrum of the donor and the absorption spectrum of the acceptor. A high value of J induces a high electron rate The rate constant of the electron exchange (kt) is equal to... 

Thus, the electron exchange rate constant decreases to very small values with the increase of the interniolecular distance. The electron exchange is observed up to distances equal to 10 A. 

The electron exchange rate constants [Rh(dmpe)3]" / " couples have been determined to be 2 x 10 and 4 x 10 M" s", respectively, from the appliction of the Marcus cross-relationship to the reactions with several ruthenium(II) pentaammine complexes. The relative values are consistent with the differences in the M—P bond distance changes (Ado = 0.068 A for Tc and 0.054 A for Re) determined by EXAFS measurements. 

The kinetic data for a series of outer-sphere electron transfer reactions between the [Rh2(02CCH3)4(CH3CN)2] couple and nickel tetraaza macrocycles and iron and ruthenium tris(polypyridine) complexes in acetonitrile have been correlated in terms of the Marcus relationship, yielding a [Rh2] electron exchange rate constant of 3.0 1.7 x 10 M A somewhat smaller value of 5.3 1.3 x... 

Analogous considerations show that the charge transfer resistance of an isolated DBA molecule is e k fk Tohms, where kex is the first-order electron exchange rate constant for the AG = 0 system. 

Table 2 Calculation of homonuclear electron exchange rate constants from heteronuclear ET reactions. Temp. 297 K, in 1 M H SO...

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