Synthesis, Crystal Structures and Antibacterial Activity of Nickel(II) and Copper(II) Complexes Derived from (E)-2-((2,3-dihydrobenzo[b][1,4]dioxin-6-yl)methylene)- N-phenylhydrazinecarbothioamide

The biosynthesis of fatty acids is essential for the survival of bacteria, and β-ketoacyl-acyl carrier protein synthase III (FabH) is a promising target for antibacterial drug development. Nickel(II) complex [NiL2] (1) and copper(II) complex [CuL2] (2), where L is (E)-2-((2,3-dihydrobenzo[b][1,4]dioxin-6-yl)methylene)-N-phenylhydrazinecarbothioamide, were synthesized and characterized by elemental analysis, IR and 1H NMR spectroscopy and HRMS. Structures of the complexes were further studied by single crystal X-ray determination, which reveals that the nickel and copper atoms in the complexes are in tetrahedral geometry. These compounds were evaluated for their antibacterial and E. coli FabH inhibitory activities.