Syntheses, crystal structures, and genotoxic studies of cis-μ-1,2-peroxo dicobalt(III) complexes

The present work describes syntheses and X-ray studies of two unusual cis-peroxo bridged dinuclear Co(III) complexes. The genotoxic studies performed on the complex reveal that the complex can be exploited for industrial applications at low concentration. Two peroxo-bridged dinuclear Co(III) complexes, {[Co-2(ea)(2)(Phen)(2)(O-2)]5.5H(2)O2Cl} (1) and {[Co-2(ea)(2)(Bipy)(2)(O-2)]2H(2)O2NO(3)} (2) (Hea=ethanolamine, Phen=1,10-phenanthroline, Bipy=2,2-bipyridine), are prepared by reaction of CoCl(2)6H(2)O or Co(NO3)(2)6H(2)O with Hea in the presence of an -diimine (Phen or Bipy) under reflux. The complexes have been characterized by IR, NMR, thermal gravimetric analysis, cyclic voltammetric (CV), powder X-ray diffraction, and single-crystal XRD techniques. Single-crystal X-ray crystallographic investigations of 1 and 2 reveal that each Co(III) is coordinated by one deprotonated ethanolamine and an -diimine chelate. The remaining coordination sites of the metal ions are satisfied by bridging peroxide (O-2(2-)) in a cis--1,2 manner. The distances [O-O=1.487(6) (1) and 1.462(3)angstrom (2) and CoCo=2.731(12) (1) and 2.7426(6)angstrom (2)] support the peroxo bridging in a cis manner in both complexes. The crystal lattice is consolidated via extensive H-bonding and interactions to form a 3-D supramolecular architecture. Thermal data are consistent with the proposed stoichiometry and presence of lattice water. The CV studies of 1 indicate the presence of a quasi-reversible redox couple ((CoCoIII)-Co-III/(CoCoII)-Co-II) in solution. Genotoxic studies are also performed on 1 to investigate the possible applications and side effects of the compounds in medicine.