Soluble Cytotoxic Ruthenium(II) Complexes with 2-Hydrazinopyridine

Abstract

New water soluble Ru(II) binary complex [Ru(C₅H₇N₃)(X)(H₂O)₂] with 2-hydrazinopyridine and its ternary complexes with X = dichloride, oxalate, malonate or pyrophosphate ligands have been synthesized. The complexes have been characterized using elemental analyses, mass, IR, and UV-Vis. spectroscopies, cyclic voltammetry, magnetic susceptibility, and thermal analysis. The complexes are diamagnetic and the electronic spectral data showed that peaks are due to low spin octahedral Ru(II) complexes. The optimized structures of the complexes 1–4 indicate distorted octahedral geometry with bond angles around the ruthenium atom ranged from 80.44° to 99.64°. The values of the electronic energies (−635 to −1145 a.u.), the highest occupied molecular orbital energies (−0.181 to 0.073 a.u.) and lowest unoccupied molecular orbital energies (−0.056 to 0.167 a.u.) indicate the stability of the complexes. The complexes are polarized as indicated from the dipole moment values (9.39–14.27 Debye). The complexes have noticeable cytotoxicity with IC₅₀ (µM): 0.011–0.062 (HepG-2), 0.015–0.080 (MCF-7), 0.015–0.116 (HCT-116), and PC-3 (0.034–0.125).