Electron spin resonance study of the cobalt(II) species formed after room-temperature photolysis of aqua(sec-butyl)bis(dimethylglyoximato)cobalt(III) in the presence of N-donor bases

Abstract

The cobalt(II) species resulting from room-temperature photolysis of aqua(sec-butyl)bis(dimethylglyoximato)cobalt(III)[Co^III(Hdmg)₂Bu^s(H₂O)] solutions in the presence of various amounts of each of 27 different N-donor bases L were studied by electron spin resonance spectroscopy and the ESR spectra compared, when possible, with those of irradiated solutions of the corresponding [Co^III(Hdmg)₂Bu^s(L)] compounds. From the ESR results, the bases could be grouped according to the position of the substituents. Both base strength and steric effects seem to play a role in the formation of 1 : 1 and 1 : 2 cobalt (II) adducts although no definite correlation between the ESR parameters determined for the various species and basicity was found.