Features of cobalt(II) complexation with azaheteracyclic ligands in the presence of a monohydroxy-substituted derivative of closo-dodecaborate anion

Cobalt(II) complexation with azaheterocyclic ligands L (L = 2,2ʹ-bipyridyl (bipy), 1,10-phenanthroline (phen) and 2,2ʹ-bipyridylamine (bpa)) in the presence of a monohydroxy-substituted derivative of the closo-dodecaborate anion [B12H11OH]2– has been studied. Depending on the nature of the organic ligand and the synthesis conditions, the coordination compounds [CoIII(bipy)2Cl2]2[B12H11OH], [CoII(phen)3][B12H11OH] and [CoII(bipy)3][B12H11OH] with the boron cluster anion as a counterion, as well as the mixed-ligand complex [CoII(bpa)2Cl2] of a known structure, have been obtained and structurally characterized. For the first time, a redox reaction leading to the formation of a cobalt(III) complex in air has been observed for a system containing cobalt(II) and a substituted derivative of the boron cluster anion without the introduction of additional oxidizing agents.