Synthesis and Spectroscopic characterization of Schiff base ligand, H2L derived from glyoxalic acid and 1,8-diaminonaphthalene and its Co(II),Ni(II),Cu(II) and Zn(II) complexes; in-vitro antibacterial and antifungal studies of L and its complexes

Mohammad Shakir^a*, Nida Shahid^a  and Asad U. Khan^b

^a Division of Inorganic Chemistry, Department of Chemistry; ^b Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India

Email: khanchemamu@gmail.com

Abstract:

The Schiff base ligand, N,N’-bis(glyoxalicacidcarboxaldiimine)-1,8-diaminonaphthalene [H₂L] has been obtained by the condensation of glyoxalic acid and 1,8-diaminonaphthalene. Its mononuclear complexes of type, [ML] [M=Co(II), Ni(II), Cu(II), Zn(II)] have been synthesized by interaction of H₂L with metal(II) nitrates. The newly synthesized Schiff base ligand [H₂L] and its complexes have been characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements  and  spectroscopic  studies  viz.,  FT-IR,  EPR,  ¹H  NMR,  Fab-Mass,  UV-vis.  and magnetic moment data. A square planar environment has been revealed around Co(II), Ni(II), Cu(II) ions while conductivity data showed non electrolytic nature of all the complexes. The antibacterial and antifungal activity of Schiff base ligand and its complexes, against S. mutants, S. pyogenes, MRSA (Gram positive bacteria), P. aeruginosa, S. typhimurium, E. coli (Gram negative bacteria), C. albicans, C. krusei, C. parapsilosis and Cryptococcus neroformans has been tested.

Keywords: Schiff base, 1,8-diaminonaphthalene, spectroscopic studies, antimicrobial activity