The photochemical reaction of tris(ethylenediamine)cobalt(III) ion with ferrocyanide

Abstract

. Can. J. Chem. 59,647 (1981). The photochemical formation of [Cl(en)2Co-N&-Fe(CN)5]2-from Co(en),)+ and Fe(CN)64-is explored. Earlier evidence established that the reaction proceeds via electron transfer. Ligand field Co(II1) excited states are clearly indicated to be effective. There is evidence that free Fe(CN)64-can scavenge these excited states or their successors arising in ion pairs with Fe(CN)64-. This suggests that the reactive excited state lifetime is at least comparable to the rate of diffusional encounters. However, racemization does not accompany reaction if (+),,,C~(en),~+ is the reactant. Wavelength studies indicate approximate wavelength independence as far as 647.1 nm. These results are in contrast with the behaviour of photosubstitution yields for Co(II1) amines. [Traduit par le journal]