Background: Arene metal complexes with acyl hydrazine derived ligands exhibit
serendipitous bonding modes and cytotoxic properties. The aim of this paper is to
synthesize arene ruthenium, rhodium and iridium metal complexes of N, N’-
Bis(picolinoyl)hydrazine ligand which exhibits discrete bonding modes. Structural elucidation
of the complexes and the evaluation of their in vitro antibacterial and antitumor
properties are also carried out.
Methods: Complexes are synthesized and characterized by spectroscopic and crystallographic
studies. The electronic properties are explored by density functional theory calculations.
The antibacterial activity is evaluated by agar well diffusion method and antitumor
activity is carried out by fluorescence based apoptosis study. Docking analysis is used to
know the interaction between the complexes and proteins under consideration.
Results: Arene ruthenium, rhodium and iridium complexes are isolated in good yields as yellow and orange
solids. Various bonding modes in complexes are justified by spectroscopic and crystallographic studies. The
preliminary investigation of these complexes revealed their antibacterial and antitumor activities. The ligand
acts as tri and tetradentate donor forming mono and dinuclear complexes. Fascinating differences were observed
in bonding modes among the complexes of ruthenium, rhodium and iridium.
Conclusion: Ligand under study forms dinuclear complexes with ruthenium as tetradentate nitrogen donor. It
forms mononuclear complexes with rhodium and iridium as nitrogen donor and dinuclear complexes with rhodium
and iridium as nitrogen and oxygen donor. Complexes under study exhibited significant growth inhibition
of Salmonella enterica ser. Paratyphi better than that of Amoxicillin. The cytotoxicity of the complexes on
normal cells is lesser than that of cisplatin which is a significant feature of the complexes under study.