Circular Dichroism Spectra of the Dicobalt(III) Complexes Containing Two Bridging μ-Hydroxo Ligands

Abstract

Abstract Five cobalt(III) complexes, [(gly)2Co(μ-OH)2Co(en)2]2+ (two geometrical isomers), [(edda)Co(μ-OH)2Co(en)2]2+ (two geometrical isomers), and [(nta)Co(μ-OH)2Co(en)2]Cl, were newly prepared and optically resolved. Their structures were assigned on the basis of visible and UV absorption, 1H NMR, and circular dichroism (CD) spectral data. It was found that the CD contributions of the two different cobalt(III) chromophores are additive in the present complex systems. The vicinal CD which is induced on one of the two cobalt chromophores by the other chiral cobalt chromophore was strong (|Δε|: ca. 2). These complexes are stable for several days in aqueous solution.