Copper(II) and zinc(II) complexes with 2-benzoylpyridine-methyl hydrazone

2-Benzoylpyridine-methyl hydrazone (HBzMe) has been obtained as well as its copper(II) [Cu(HBzMe)Cl2] (1) and zinc(II) [Zn(HBzMe)Cl2] (2) complexes. Upon re-crystallization in 1 – 9 DMSO:acetone conversion of 1 into dimeric [Cu(BzMe)Cl]2 (1a) occurred. The crystal structures of HBzMe, 1, 1a, and 2 were determined. HBzMe adopts the ZE conformation in the solid. In all complexes the hydrazone adopts the E configuration to attach to the metal through the NpyN2O chelating system. In 1 and 2 a neutral hydrazone coordinates to the metal center while in 1a deprotonation occurs with coordination of an anionic ligand. 1a presents a dimeric structure, having two copper(II) ions per asymmetric unit. Two chlorides are also present in the copper coordination sphere, which act as bridging ligands and connect the copper centers to each other.