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 pendantvinyl groups, has been investigated. The resulting tetrahedral ZnX2L2complexes, where X = Cl, Br, or I, andL = N-vinylimidazole (NVI) or 4-vinylpyridine (4VP), were exposed to gamma rays in an oxygen-free atmo-sphere. SEM-EDS, TGA, DSC, Elemental analyses, Mass Spectrometry, NMR, IR, and single-crystal X-ray dif-fraction of thefive Zn(II) complexes are herein reported. After exposure to gamma rays (25 kGy), an alteration inthe structure of the irradiated aggregates compared with the starting complexes was detected. Both, startingcomplexes and irradiated derivatives, exhibited antimicrobial activity in preliminary assays in vitro againstGram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli); where the performance ofZnBr2(4VP)2and irradiated [ZnI2(4VP)2]-(25 kGy) was outstanding.