Kinetics of electron transfer from tris(picolinato)chromate(II) to iron(III)

Abstract

The mechanism of the electron-transfer reaction from tris(picolinato)chromate(II) to iron(III) has been studied by spectrophotometry and stopped-flow techniques. The rate constants and the activation parameters for the inner-sphere process involving the formation and decay of the binuclear intermediate have been determined. The relevant thermodynamic and kinetic parameters for the formation of tris(picolinato)chromate(II), required for understanding the redox mechanism, have been determined from spectrophotometric and stopped-flow experiments. Some of the results were verified for T-jump measurements. All the values have been reported at 25 /sup 0/C and ionic strength 2.3 M unless otherwise indicated. For the binuclear intermediate, the following rate constants were obtained: k(formation) = 14.1 M/sup -1/ s /sup -1/; k(decay) = 5.6 x 10/sup -4/ s/sup -1/. 27 references, 10 figures, 7 tables.