Synthesis, characterization, optical and anti-bacterial properties of benzothiazole Schiff bases and their lanthanide (III) complexes

Abstract Two new Schiff base ligands comprising benzothiazole derivatives, namely (N,N',E,N,N'E)-N,N'-(1,3-phenylenebis(methanylylidene))bis(5-nitrobenzo[d]thiazoL2-amine (L1) and (N,N',E,N,N'E)-N,N'-(1,3-phenylene-bis(methanylylidene))bis(5-methylthiazo-L2-amine (L2), have been synthesized and thoroughly characterized using FTIR, 1H NMR, mass UV/vis and fluorescence spectral techniques. Further, L1 and L2 lead to the formation of lanthanide complexes 1-6 with Ce(III), Nd(III), and Pr(III) ions in 1:2 (metal : ligand) stoichiometry. UV/vis spectra of L1, L2 and 1-6 exhibit characteristic ligand centered absorptions in the range of 230-350 nm. Besides, both ligands and complexes show significant emissions and good anti-bacterial activity against pathogenic bacteria. Ligands and complexes display anti-bacterial activity against bacteria Staphylococcus aureus (S.aureus) (MTCC 1144) causing skin infection and food poisoning and pimple-causing bacteria propionic bacteria acnes (P. acnes) (MTCC 1951).