Zinc(II) and Cobalt(II) Complexes Derived from 4-Benzyloxy-2,6-bis(1-methyl-2-benzimidazolyl)pyridine: Synthesis, Crystal Structures, Spectroscopic Properties and Antitumour Activities

Two metal complexes, [Zn(bmbp)Cl 2 ]·H 2 O ( 1 ) and [Co(bmbp) 2 ](ClO 4 ) 2 ·DMF·H 2 O ( 2 ) (bmbp = 4-benzyloxy-2,6-bis(1-methyl-2-benzimidazolyl)pyridine), have been synthesized and characterized. X-ray crystal structure analysis for complex 1 reveals that the Zn(II) atom is penta-coordinated with three nitrogen atoms of the ligand and two chlorine atoms in the coordination sphere, adopting a distorted square pyramidal geometry. For complex 2 , the central Co(II) atom is bonded by six nitrogen atoms from two ligands in a distorted octahedral fashion. The two complexes feature 1D chain structures generated by C–H⋯π interactions. The thermal stabilities and spectroscopic properties of the complexes have been studied. Both complexes exhibit inhibition on the growth of the Eca109 cancer cells, but show lower antitumor activity than cisplatin. Graphic Abstract Two zinc(II) and cobalt(II) complexes based on 4-benzyloxy-2,6-bis(1-methyl-2-benzimidazolyl)pyridine, which exhibit inhibition on the growth of Eca109 cancer cell, were synthesized and characterized by X-ray single crystal structure analysis.