Electron-transfer reactions of cobaloximes. Part II. The transition from outer- to inner-sphere mechanisms with vanadium(II): a non-linear free-energy relation

Abstract

The reduction of a series of cationic cobaloximes of the form [Co(Hdmg)₂L₂]⁺ by V²⁺(aq) has been investigated [Hdmg = dimethylglyoximato(1–); L = EtNH₂, PhNH₂, py, or 3,5-Me₂py]. Rate constants and activation parameters at 25 °C are reported. A plot of ΔG^‡ for these reactions against E_½ for the polarographic reduction is used to illustrate the progression from inner- to outer-sphere mechanism as the base strength of the axial ligands if lowered.