Chemical Science Review and Letters ISSN 2278-6783 Chem Sci Rev Lett 2015, 4(15), 851-859 Article CS072046073 851 Research Article Synthesis and Characterisation of some novel Schiff base metal complexes: Spectral, XRD, Photoluminescence and Antimicrobial Studies Rajendran Jayalakshmi and Rangappan Rajavel* Department of chemistry, Periyar University, Salem-636 011, Tamil Nadu, India Abstract Schiff base ligands are potentially capable of forming stable complexes with most transition metal ions, which act as model compounds for biologically important species. Cu (II), Co (II), Ni (II) and Mn (II) Schiff base metal complexes was prepared by the condensation of benzil and 2,6-diamino pyridine in 1:1 molar ratio. The chemical structures of the Schiff- base ligand and its metal complexes were confirmed by various spectroscopic studies like IR, UV-VIS, 1 H NMR, TGA/DTA, Powder XRD, Molar conductance, and Photo luminescence. The free Schiff base ligand and its complexes have been tested for their antibacterial activity using disc diffusion method. From the biological studies, the complexes exhibit more activity than the ligand. Keywords: Schiff base; IR; UV; Photo fluorescence; Antimicrobial activity *Correspondence Author: Rangappan Rajavel Emails: drrajavelpu@gmail.com Introduction Metal-chelate Schiff base complexes have continued to play the role of one of the most important stereo chemical models in main group and transition metal coordination chemistry due to their preparative accessibility, diversity and structural variability(Garnovskii.,1993). Schiff bases have gained importance because of physiological and pharmacological activities associated with them. Schiff base metal complexes have ability to reversibly bind oxygen in epoxidation reactions [1], biological activity [2-4], catalytic activity in hydrogenation of olefins [5, 6] non-linear optical materials and [7] and photochromic properties [8]. The Schiff base complexes were also used as drugs and they possess a wide variety of antimicrobial activity against bacteria, fungi and it also inhibits the growth of certain type of tumours [9, 10]. The symmetric nature of a number of homo dinuclear transition metal derived metallo- biosites and of the ability of the individual metal ions to have quite distinct roles in the functioning of the metalloenzyme concerned has led to a search for symmetrical dinucleating ligands which will give binuclear complexes capable of acting as models for the metallobiosites [11, 12]. 2, 6-Diamino-pyridine is a medium- production-volume chemical used as a pharmaceutical intermediate and a hair dye coupler in oxidation/permanent formulations. Although mutagenic activity has been reported, here in the present work we report the formation of Schiff base ligand from the condensation of 2, 6-diamino pyridine with benzil and the complexation with metal ions to form potentially active macrocyclic binuclear Schiff base metal complexes. Experimental Physical measurements (apparatus and experimental conditions) By using the Perkin-Elmer CHN 2400 instrument, we determined the Carbon, Hydrogen and Nitrogen contents present in our Schiff base metal complexes. Molar conductance of the metal complexes was determined by using Elico model conductivity meter in DMF (10 -3 ) solution was measured at 27±3°C. By using the Thermo Nicolet, Avatar 370 model FT-IR spectrometer (using KBr disc in the range of 4000- 400 cm -1 ) the Infrared spectra were recorded. From the Perkin-Elmer Lambda 40(UV-Vis) spectrometer, electronic spectra were conducted at 300 K