S-Sulphinates of cobalt(III) planar chelates and sulphur dioxide insertion into a cobalt(III)-carbon bond

Abstract

The reactivity of the cobalt-carbon bond towards sulphur dioxide has been investigated in the compounds Rco¹¹¹(L)B where L = N,N'-ethylenebis(salicyl-aldiminato), N,N'-phenylenebis(salicylaldiminato), or bis(dimethylg1yoximato);B = water or pyridine. In the Schiff base complexes, for R = alkyl, insertion into the cobalt-carbon bond proceeds smoothly to give the corresponding sulphinato derivatives. Reaction also occurs with methylcobaloxime and a pentafluorobenzene- cobalt-Schiff base compound, but the products are not so well defined. There is no reaction with cobalt-aryl bonds for any of the chelates. The alkane- and arene- sulphinato complexes can be synthesized by an alternative oxidative-addition reaction NaCOL+RSO₂Cl or a replacement reaction XCoL+AgSO₂R or NaSO₂R (X = Cl,I). The infrared spectra of the complexes show that the sulphinato group is bonded in the manner shown: (See diagram in article) The p.m.r. spectra of the complexes are discussed in some detail. Reactions of the sulphinato derivatives with donor molecules and the halogens are briefly described.