Complexes of manganese(II), iron(II), cobalt(II), nickel(II), copper(II), and zinc(II) with a bishydrazone

Complexes of manganese(II), iron(II), cobalt(II), nickel(II), copper(II), and zinc(II) with a bishydrazone formed by the condensation of isatin hydrazone with salicylaldehyde were synthesized and characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility data, UV-Visible, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as monobasic tridentate, coordinating to the metal ion through the azomethine nitrogen, phenolate oxygen and carbonyl oxygen of the isatin moiety. Manganese(II), iron(II), and cobalt(II) complexes exhibited 1 : 2 metal ligand ratio while nickel(II), copper(II), and zinc(II) complexes revealed 1 : 1 metal ligand stoichiometry. The EPR spectral data of the copper(II) complex revealed that the metal-ligand bond has considerable covalent character. The XRD pattern of the nickel(II) complex showed that the metal complex possesses orthorhombic crystal lattice. The ligand and the metal complexes were screened for their antibacterial activity and it has been observed that the complexes are more potent bactericides than the ligand.