Syntheses, Characterization, Crystal Structures and Antimicrobial Activity of 4-Bromo-N′- (pyridin-2-ylmethylene)benzohydrazide and Its Cobalt(III) and Manganese(II) Complexes

A new hydrazone compound 4-bromo-N'-(pyridin-2-ylmethylene)benzohydrazide (HL) and its cobalt(III) and manganese(II) complexes, [CoL2]NO3 center dot 2H(2)O (1) and [MnL2] (2) were prepared. They were characterized by a variety of physicochemical techniques. Molecular structures of the compounds were further confirmed by single crystal X-ray crystallography. The coordination geometry around the cobalt atom in complex 1 and the manganese atom in complex 2 are octahedral, with two pyridine N atoms, two imino N atoms, and two enolate O atoms from the ligands. The compounds were evaluated for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence) and antifungal (Candida albicans and Aspergillus niger) activities by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method.