The cobalt(II) complex [CoCl 2(2, 6-iPrC 6H 3-BIAO)] 2 (1) of rigid unsymmetrical imine, carbonyl mixed ligand [N-(2, 6-diisopropylphenyl)-imino]acenapthenone] (2, 6-iPrC 6H 3-BIAO) (L1) can be achieved by the reaction of CoCl 2 and neutral [N-(2, 6-diisopropylphenyl)-imino]acenapthenone] ligand. When ligand L1 reacted with CuCl in dichloromethane solution, only nitrogen coordinated copper complex [CuCl(2, 6-iPrC 6H 3-BIAO)] (2) was obtained. In the solid-state structure, compound 1 is dimeric through the chelating two μ 2 chlorine atoms and each cobalt atom adopts either a distorted trigonal bipyramidal or a distorted square pyramidal arrangement. In contrast, the molecular structure of compound 2 reveals that copper is coordinated by imino nitrogen and adopts a linear arrangement around the central metal atom. The crystal structure of the rigid bidentate mixed nitrogen and oxygen ligand (2, 6-iPrC 6H 3-BIAO) (L1) is also reported. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.