Syntheses and molecular structures of cis and trans monomeric ferrocenecarboxylatocopper(II) complexes with imidazole derivatives

Abstract

The products of the reactions of 1,2-dimethylimidazole and N-methylimidazole with tetrakis(ferrocenecarboxylato)dicopper(II) have been isolated and characterized by single-crystal X-ray diffraction. They are the monomeric species cis-bis(1,2-dimethylimidazole)bis(ferrocenecarboxylato)copper(II)1 and trans-bis(ferrocenecarboxylato)bis(N-methylimidazole)copper(II)2, respectively. In each complex the copper ion is in a square-planar environment consisting of two imidazole nitrogen atoms and a carboxylate oxygen atom from each ferrocenecarboxylate ligand. The second oxygen atoms of the carboxylate functionalities are involved in weak interactions with the copper ions. The η⁵-C₅H₄ and η⁵-C₅H₅ rings of the ferrocenyl moieties are nearly eclipsed with deviations from the eclipsed conformation of 9.7 and 5.5° for 1 and 4.4° for 2.