Synthesis, characterization, antimicrobial and in vitro cytotoxic evaluation of trinuclear heterobimetallic complexes of Ni (II) derived by the reaction of [Ni(C10H10N2)2]Cl2 with dialkyl/diaryl organometallic dichlorides

Abstract

The newly designed trinuclear heterobimetallic complexes [Ni(L)2(M)2R4Cl2] were synthesized by using methanolic solution of mononuclear Ni (II) complex and various organometallic dichlorides (where L = 1,8‐diaminaphthalene [C10H10N2], M = Sn [IV], Si [IV], Ti [IV] and Zr [IV] and R = Ph, Me, C5H5, etc.). The synthesized complexes were characterized on the basis of physico‐chemical and spectral (FTIR, UV‐visible, 1H‐NMR, 13C‐NMR, 29Si‐NMR, 119Sn‐NMR, Mass, and PXRD) studies. IR spectroscopy confirmed the coordination of ‐NH2 group to the metal centre. PXRD patterns showed the crystalline nature of all the synthesized complexes. Among the synthesized complexes, mononuclear metal complex adopted square planar geometry, while trinuclear heterobimetallic complexes adopted distorted octahedral geometry. This geometry is also supported by DFT calculations. The in vitro antimicrobial effectiveness of these resulting compounds has been scrutinized against a number of bacterial strains (Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, and Staphyloccocus aureus) by agar disc diffusion method and fungal strains (Candida albicans, Fusarium oxysporum and Aspergillus niger) by disc diffusion method, and promising results were attained. The in vitro cytotoxicity activity of the synthesized complexes has been scrutinized against human cervical cancer cells (HeLa) and human breast cancer cells (MCF‐7) using MTT assay and showed higher cytotoxicity than cis‐platin. Furthermore, their non‐toxic nature was confirmed when they tested against human normal keratinocyte cells (HaCaT). The results indicated better biological activity of heterobimetallic complexes than their monometallic complex.