The Corrosion Inhibition Efficiency of Isatin and Methionine Schiff Base and Structural Characterization of it’s Complexes 

P. S. Suja Pon Mini^1*, S.Theodore David Manickam², R. Antony³, S. Brillians Revin^4
1,4 Assistant Professor, Department of Chemistry, Francis Xavier Engineering College, Scad Group of Institutions, Tirunelveli–627003, Tamilnadu, India
²Centre for Scientific and Applied Research (C-SAR), PSN College of Engineering and Technology, Tirunelveli-627 152, Tamil Nadu, India
³Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.

 A B S T R A C T
A new class of Schiff base ligand  derived from isatin and methionine (AB) and its  Co(II), Cu(II), Ni(II) and Zn(II) complexes was synthesized and characterized by elemental analysis, magnetic study, molar conductance measurement and spectroscopic methods such as ¹³CNMR, FT-IR, UV, EPR, XRD and Fluorescence spectra as well as thermal studies. In all the complexes the Schiff base coordinates the metal ions in a tetradentate manner. The elemental analysis suggests the stoichiometry to be 1:1 (metal: ligand). The g values calculated for copper (II) complexes indicate the presence of the unpaired electron in the d x2-y2 orbital. XRD studies reveals the nano crystalline behavior of Cu(II) complex. The Corrosion inhibition activity of the ligand in acid media was also examined by weight loss experiment and optical microscopic method. The biological activity of the ligand and metal (II) complexes have been tested against few gram positive and gram negative bacterial and fungal species, and found to show more activity compared to the control. The interaction of the complexes with DNA was studied by the absorption spectra which exhibit a slight red shift with hypochromic effect.
Keywords: Schiff base,  Metal Complex,  EPR, Heterocyclic, Inhibition efficiency, Isatin, Methionine