International Journal of ChemTech Research CODEN( USA): IJCRGG ISSN : 0974-4290 Vol.1, No.3 , pp 535-538, July-Sept 2009 Elucidation of Structures of Cu II Complexes of Dibasic Tetradentate (OO’ NO donor) Ligand K.P.Srivastava*, Balram Singh 1 & Vineeta Singh Department of Chemistry, Jai Prakash University, Chapra-841301, INDIA. 1- Tapeshwar Singh Inter College, Chapra-841301. E-mail: kpsri@yahoo.com ABSTRACT: The ligand 2-(acetylacetonato)-iminobenzohydroxamic acid and its different mixed ligand novel complexes with Cu II having specific formulae have been synthesized and characterised by elemental analyses, magnetic and conductance measurements, IR and electronic spectral studies. The ligand was found to behave in dibasic tetradentate (OO’ NO donor) manner. All the synthesized Cu II complexes were non-electrolyte with magnetic moment ranging from 1.92 to 2.10 BM. The structural assessment of the complexes has been carried out based on electronic, infrared and molar conductivity values. All the complexes were found to be of octahedral geometry. KEYWORDS: Hydroxamic acids; tetradentate ligand; octahedral complexes; magnetic moment. INTRODUCTION: Structural modification of organic molecules has considerable biological relevance. Further, coordination of a biomolecules to the metal ions significantly alters the effectiveness of the biomolecules. There is a correlation between the biological activities with geometry of the complexes. Hydroxamic acids are versatile reagents for organic and inorganic analyses [1, 2]. Their derivatives are biochemically highly active and find applications in medicinal use [3]. The acetylacetonato group containing derivatives of hydroxamic acid have aroused considerable interests over decades [4]. Hydroxamic acids having one or more –CONHOH groups have been extensively studied as a consequence of their biological importance which is related with their ability to form metal ion complexes [5]. These acids are important also due to their pharmacological, toxicological and pathological properties [6-7]. Besides, they have a great number of applications in analytical chemistry. Monohydroxamic acids (such as benzohydroxamic acid, C 6 H 5 CONHOH = BHA) after deprotonation acts as bidentate ligands forming octahedral complexes with a series of metal ions via co-ordination through the two oxygen atoms of the -CONHO - group. This type of co- ordination has been characterized in previous studies with Ni II , Co II and Zn II ions, which indicated the formation of octahedral complexes both in the solid state and in solution [8]. In continuation [9-13] of our work on the complexes with the hydroxamic acid derivative ligands we report the Cu II mixed ligand complexes formed by one hydroxamic acid {2-(acetylacetonato)- iminobenzohydroxamic acid [AIBHA-H 2 ] }[Figure-1] taken as the primary ligand (A) and a secondary ligand (B) represented either by quinoline, pyridine or picolines in this research article. The primary ligand (AIBHA) potentially acts as tetradentate (OO’ NO) ligand but all these secondary ligands act as monodentate ligand. EXPERIMENTAL Materials: All the chemicals and reagents used were of AnalaR grade. Anhydrous grade alcohols, DMF, and DMSO were obtained from Fischer scientific. 2- aminobenzhydroxamic acid and acetylacetone (in enolic form) were obtained from Aldrich (USA). The metal chlorides/acetates used were of BDH AR grade in the present investigation. All reactions and experimental manipulations were carried out at appropriate temperature. Physico chemical measurements: Elemental analysis (C, H & N) of ligand and complexes was carried out in micro analytical laboratory on Carl-Ebra 1106 elemental analyzer. Metal in the complexes was estimated following standard procedure [14]. The molar conductance measurements were carried out for the 10 -3 M solutions of complexes in DMSO