A study on tailor made ruthenium sulphoxide complexes: Synthesis, characterization and application

Abstract

In this study, a dinucleating spacer incorporating two 2-aminopyridine units was used to prepare seven novel dinuclear compounds. These molecules were characterized by elemental analyses, conductivity measurements, magnetic susceptibility, FT-IR, FAB-Mass, electronic, 1H-NMR and 13C{1H} - NMR spectral studies. The complex [{trans,mer-RuCl2(DMSO)3}2(μ-5,5′ - methylenebis(2-aminopyridine))]·2DMSO (2) was also characterized through 1H-1H COSY NMR. There are mainly three different formulations, [{cis,fac-RuCl2(SO)3}2(μ-MBAP)]·2SO; [{trans,mer-RuCl2(SO)3}2(μ-MBAP)]·2SO and [{trans-RuCl4(SO)}2(μ-MBAP)]2-[X]2+; where SO = DMSO / TMSO; MBAP = 5,5′-methylenebis(2-pyridinamine) and [X]+ = [(DMSO)2H]+, Na+ or [(TMSO)H]+. The coordination was found through cyclic nitrogen of the pyridine ring in an octahedral environment for both metal centres. The chemical behaviour of [{cis,fac-RuCl2(DMSO)3}2(μ-5,5′-methylenebis(2-pyridinamine))]·2DMSO (1) and (2) in aqueous solution with respect to time was observed by conductivity measurements and UV-Vis spectrophotometry. All complexes were found to possess prominent antibacterial activity against Escherichia coli in comparison to chloramphenicol and gatifloxacin.