Synthesis,characterization and DNA nuclease activity of oxo-peroxomolybdenum(VI) complexes

The synthesis and structural characterization of two oxo-peroxo molybdenum(VI) complexes, [Mo(O)(O)₂(PAA)]^? (1) and [Mo(O)(O)₂(PAH)]^? (2), with phenylacetic acid (PAA) and 2-phenylacetylhydroxamic acid (PAHH) ligands have been accomplished. The coordination geometry of the oxo-peroxo molybdenum(VI) complexes is found to be pentagonal bipyramidal where, in both cases, the ligands are coordinated in bidentate fashion through oxygen atoms. The binding affinities of 1 and 2 with calf-thymus DNA (CT DNA) are determined using absorption spectroscopic measurements. The spectroscopic as well as cyclic voltammetric (CV) studies and viscosity measurements indicate that both complexes interact with CT DNA in the groove. The intrinsic binding constants are 5.2 × 10⁴ M^?1 and 7.3 × 10⁴ M^?1 for 1 and 2, respectively, from UV–vis studies. Complexes 1 and 2 show nuclease activity with plasmid DNA in the presence of H₂O₂. Concentration-dependent nuclease study suggests that 2 possesses higher ability to cleave plasmid DNA compared to 1. The experimental results of the binding of 1 and 2 with DNA are further supported by molecular docking studies.