Study, Synthesis and Characterisation of Mixed Ligand Complexes of Alkali Metal Salt of Some Organic Acids with 3-Nitro-1,5-O-Tolyl Formazanes

Abstract:-The design, synthesis and characterization of suitable mixed ligand around a metal center is important task for effective reaction. A number of mixed ligand complexes of alkali metal salt of o-nitro phenol, 1-nitroso-2-naphthol, 8-hydroxy quinolone and salicylic acid has been synthesized and characterized .IR studies indicate the presence of hydrogen bonding. Ease of complexation as well as the yield has been found to increase with the increase in radius of alkali metal cations. Low value of molar conductivities suggests that the mixed ligand complexes are covalent in nature. The complexes have stimulated intense interest because of their unique molecular architecture and biological properties.

Key Words: Mixed ligand complexes, NOTF, IR-spectra

INTRODUCTION

Metal complexes of poly azo ligands have been important Metal derivatives of aryl formazans are coloured and are of great interest as pigments and analytical reagents. Formazanes are known to possess anticancer, antifungal and antiviral properties1,2 in an attempt to explore the study of formazanes further, we have synthesized and characterised a number of alkali metal complexes with the ligand 3-nitro-1,5-di-o-totyl formazan. A literature survey3-7 reveals that the ligand 3-nitro-1,5-di-o-totyl formazan (NOTF) which has two possible coordination sites, has remained its chelating ability. The present investigation has been undertaken to examine the behavior of these formazans towards alkali metal salts. We have prepared a number of mixed ligand complexes having general formula ML.HL’, where M=Li, Na or K;L = deprotenated O-nitrophenol,1-nitroso-2-naphtol, 8-hydroxy quinolone and salicylic acid, HL’ = NOTF. II. EXPERIMENTAL Preparation of NOTF The ligand 3-nitro -1,5-o-totyl formazans was prepared by the methods as described below: O-toluidine (21.4g) was dissolved in a mixture of 75 ml of conc. HCL and 40ml of water. The resulting solution was cooled to 0oC. The solution was diazotized by adding an ice cold solution of NaNO2 (15g). Nitro methane 6g was dissolved in aqueous solution of NaOH (8g) in minimum quantity of water while the temperature was maintained below 10oC. The alkaline solution of nitro methane was then added to the diazotized solution of o-toluidine in small amounts and with constant stirring.
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