Photochemical and antibacterial properties of ruthenium complex of N,N’-bis(benzimidazole-2yl-ethyl)ethylenediamine under visible light: Experimental and theoretical studies

Abstract

Abstract Complex [Ru(II)L1ClP(Ph3)]Cl (L1= N,N′-bis(benzimidazol-2-yl-ethyl)ethylenediamine) was prepared, and characterized completely by different analytical methods, and its photochemical behavior was studied under visible light. 31P NMR results showed that a light assisted structural transformation in the complex occurred. The formation of different ruthenium complexes was also recorded by LC-MS: [Ru(II)L1DMSO)]2+ (m/z = 563, RT = 19.9 min); [Ru(II)L1DMSO(H2O)]2+ (m/z = 581, RT = 15.69 min); [Ru(II)L1DMSO(H2O) (MeOH)]2+ (m/z = 611, RT = 17.0 min); Ph2P(Cl) = O (m/z = 242, RT = 13.3 min). Theoretical study was used to interpret the structural change. The change of electron density ρ(r) (dipole moment changes from 4.77 to 8.85 D) was observed in benzimidazole group in the excited state, altering the structural parameters of the complex. Furthermore, antibacterial study performed for the complex shows a high toxicity with bacterial cell even at low concentrations (50 μL, 0.5 mM). This is consistent with low cell growth factor with [Ru(II)L1ClP(Ph3)]Cl, established by Atomic Force Microscopy (AFM).