Synthesis, spectral, thermal studies of Co(II), Ni(II), Cu(II) and Zn(II)-arginato Complexes. crystal structure of monoaquabis(arginato‐κO,κN)copper(II). [Cu(arg)2(H2O)].NaNO3

Abstract

Transition metal complexes of arginine (using Co(II), Ni(II), Cu(II) and Zn(II) cations separately) were synthesized and characterized by FTIR, TG/DTA-DrTG, UV-Vis spectroscopy and elemental analysis methods. Cu(II)-Arg complex crystals was found suitable for x-ray diffraction studies. It was contained, one mole CuII and Na+ ions, two arginate ligands, one coordinated aqua ligand and one solvent NO3 - group in the asymmetric unit. The principle coordination sites of metal atom have been occupied by two N atoms of arginate ligands, two carboxylate O atoms, while the apical site was occupied by one O atom for CuII cation and two O atoms for CoII, NiII, ZnII atoms of aqua ligands. Although CuII ion adopts a square pyramidal geometry of the structure. CoII, NiII, ZnII cations have octahedral due to coordination number of these metals. Neighbouring chains were linked together to form a three-dimensional network via hydrogen-bonding between coordinated water molecule, amino atoms and O atoms of the bridging carboxylate groups. CuII complex was crystallized in the monoclinic space group P21, a = 8.4407(5) Å, b = 12.0976(5) Å, c = 10.2448(6) Å, V = 1041.03(10) Å3, Z = 2. Structures of the other metal complexes were similar to CuII complex, because of their spectroscopic studies have in agreement with each other. Copper complex has shown DNA like helix chain structure. Lastly, anti-bacterial, anti-microbial and anti-fungal biological activities of complexes were investigated. Copyright © 2014 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany.