Co(III), Ni(II), Zn(II) and Cd(II) complexes with 2-acetyl-2-thiazoline thiosemicarbazone: Synthesis, characterization, X-ray structures and antibacterial activity

Abstract The new ligand 2-acetyl-2-thiazoline thiosemicarbazone (HATtsc) and the complexes [Co(ATtsc) 2 ] 2 [CoCl 4 ]·2H 2 O ( 1 ), [Co(ATtsc) 2 ]NO 3 ·H 2 O ( 2 ), [Ni(HATtsc) 2 ](NO 3 ) 2 ( 3 ), [ZnCl 2 (HATtsc)]·CH 3 CN ( 4 ), [{CdCl(HATtsc)} 2 (μ-Cl) 2 ]·2H 2 O ( 5 ) and [{Cd(NO 3 )(HATtsc)} 2 (μ-NO 3 ) 2 ] ( 6 ) were isolated and characterized by a variety of physico-chemical techniques and X-ray diffraction. The structure of HATtsc in 1 and 2 presented a thiolate form while in 3 – 6 the thione form was present, as it was in free ligand. In addition, we studied the antibacterial activity of the ligand and complexes 2 – 6 against some representative bacteria. Cd(II) complexes were more active against Staphylococcus epidermidis , Staphylococcus aureus , Enterococcus faecalis , Escherichia coli and Bacillus subtilis than organic ligand. Conversely, Cd(II) compounds seemed to interfere in the cell separation of B. subtilis .