Heterotrimetallic Ru(II)/Pd(II)/Ru(II) complexes: Synthesis, crystalstructure, spectral characterization, DFT calculation and antimicrobial study

New ruthenium(II) mononuclear complexes of the type [RuCl2(PPH3)(2)(eta(2)-triamine)] (2) [RuCl(PPH3)(2) (eta(3)-triamine)]Cl (5) (triemine = N-1-(2-aminoethyl)-1,2-ethanediamine) have been synthesized by reacting [RuCl2(PPH3)(3)] (1) with one mole equivalent of N-1-(2-aminoethyl)-1,2-ethanediamine in dichloromethane. Reaction of (2) with half-equivalent of (PhCN)(2)PdCl2 or Pd(OAc)(2) in dichloromethane as a solvent afforded two novel heterotrimetallic Ru(II)-Pd(II)-Ru(II) complexes, [(RuCl2)-Cl-II(PPh3)(2)(triamine)](2) [(PdX2)-X-II](X = Cl, OAc) (3 and 4), bearing bioactive ligand. The progress of the undertaken reactions was monitored by P-31{1H} NMR and FTIR. Crystal structure of complex 2 was confirmed by X-ray diffraction. The absorption spectrum of 2 in dichloromethane was modeled by time-dependent density functional theory (TD-DFT). The in vitro antimicrobial studies of complex 2-5 against an array of microorganisms (bacteria and fungi) were conducted. Complexes 3 and 4 exhibit high dual antibacterial and antifungal activity inhibiting microorganisms possibly via hydrolytic pathway which further evidenced by electrochemical analyses. The complexes 3 and 4 show a high inhibitory activity at 200 mu g/ml concentration, suggesting that complexes 3 and 4 are two efficient catalytic inhibitor of microorganisms and further, they should be tested against cancer strains. (C) 2013 Elsevier B.V. All rights reserved.