Zinc heterocyclic vinyl complexes and their gamma-irradiated derivatives: From the metal to antimicrobial materials

Abstract

The synthesis in water of two series of halogen Zn(II) complexes with heterocyclic ligands, containing pendant vinyl groups, has been investigated. The resulting tetrahedral ZnX2L2 complexes, where X = Cl, Br, or I, and L = N-vinylimidazole (NVI) or 4-vinylpyridine (4VP), were exposed to gamma rays in an oxygen-free atmosphere. SEM-EDS, TGA, DSC, Elemental analyses, Mass Spectrometry, NMR, IR, and single-crystal X-ray diffraction of the five Zn(II) complexes are herein reported. After exposure to gamma rays (25 kGy), an alteration in the structure of the irradiated aggregates compared with the starting complexes was detected. Both, starting complexes and irradiated derivatives, exhibited antimicrobial activity in preliminary assays in vitro against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli); where the performance of ZnBr2(4VP)2 and irradiated [ZnI2(4VP)2]-(25 kGy) was outstanding.