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RAMAN AND SERS INVESTIGATION OF NEW SYNTHESIZED NICOTINIC ACID METALLIC COMPLEXES T. Jurca1, S. Cavalu1, S.Cîntă Pînzaru2 1 University of Oradea, Faculty of Medicine and Pharmacy, Nicolea Jiga 29 , Oradea Romania 2 Babes Bolyai University, Molecular Spectroscopy Dept., Kogălniceanu 1, RO 400084 Cluj-Napoca, Romania An important direction in the coordination chemistry of pharmaceutical compounds is the development of the synthesis regarding the complexes containing biologically active metals and physiologically active organic ligands, where coordination-bound metals possess significantly higher efficiency and low toxicity. Nicotinic acid or niacin, a water-soluble B complex vitamin and antihyperlipidemic agent, is 3-pyridincarboxylic acid (C6H5NO2) and play an important role in the biochemical redox processes. The functional group of nicotinic acid is capable to form different complexes with trace metals. Nicotinic acid and their complexes combination with copper, cobalt and cadmium acetate (Ac) were characterized using Raman spectroscopy. SERS spectrum of the nicotinic acid was recorded in order to draw conclusions concerning the adsorption behaviour of the ligand to a metal surface versus metal coordination to a metal complex. SERS results revealed a chemisorption of the ligand species through the N ring atom with respect to the metal surface. The spectral data of the complexes suggested a bidentate coordination with the proposed structure given in the Fig. 1. The differences between the chemisorbed oriented geometry and the coordinated ligand are discussed. OH Ac N C=O O=C Me N Ac HO Fig. 1. Schematic molecular structure of the metal-nicotinic acid complexes. References [1] S. Cîntă Pînzaru, I.Pavel, N. Leopold, W. Kiefer, J. Raman Spectrosc., 335: 338-346, 2004. [2] T. Iliescu, S.Cîntă, S. Astilean, I. Bratu, J. Mol. Struct. , 193, 410-411, 1997. [3] S. Cîntă, M.Venter, T. Iliescu, O. Cozar, I.Haiduc, W. Kiefer, Vibr. Spectrosc., 19, 223-226, 1999. [4] T. Jurca, S. Cavalu, S.Cîntă, V. Simon, Studia Physica, UBB, XLIV 1, 457-460, 2003.