Half sandwich platinum group metal complexes of thiourea derivative ligands with benzothiazole moiety possessing anti-bacterial activity and colorimetric sensing: Synthesis and characterisation

Abstract Complexes 1–9 were prepared by the reaction of [(arene)MCl 2 ] 2 (arene =  p -cymene, Cp*; M = Ru, Rh and Ir) with thiourea derivative ligands L1 , L2 and L3 . These complexes have been isolated as cationic bidentate (N, S), neutral bidentate (N, S) as well as neutral mono-dentate (S) complexes. Anti-bacterial activity studies were carried out for these complexes as well as the ligands against Gram-positive bacteria ( Staphylococcus aureus ) and Gram-negative bacteria ( Escherichia coli ; Klebsiella pneumoniae ) in which all the complexes (except complexes 2 and 6 ) as well as the ligands (except L3 ) showed anti-bacterial activity. In addition to the biological studies, colorimetric sensing study using silver nanoparticles was also carried out where, ligands L1 and L3 showed agglomeration effects.