Anaerobic photodecomposition of alkylaquocobaloximes in aqueous solution

Abstract

The photochemical decomposition of alkylaquocobaloximes in aqueous solution under anaerobic conditions depends critically on the presence of acid. At pH 2, photoreaction is fast and wavelength-independent (ϕ > 0.1 for several alkyl substituents) and involves the production of aqueous cobalt(II) ion and radical intermediates which yield products typical of abstraction and dimerisation reactions. At pH 7, photoreaction is ca. ten-fold less efficient to yield [Co^II(Hdmg)₂(OH₂)₂][Hdmg = dimethylglyoximate(1–)] together with an alk-1-ene derived from the axial alkyl ligand.