Synthesis, spectral and thermal studies of some polymeric mixed ligand uracil–hydrazide complexes with transition metal ions

Abstract

Polymeric mixed ligand complexes of the type [MCl(ur)(Bh)(H2O)] n and [M(ur)(Inh)(H2O)2] n , where, M = Co(II), Ni(II), Cu(II) and Zn(II), UR = uracil, Bh = benzoic acid hydrazide and Inh = isonicotinic acid hydrazide, have been prepared and characterized by elemental analyses, magnetic susceptibility measurements, thermo grams (TGA) studies, electronic, IR and ESR spectral studies. The magnetic moments and electronic spectral studies indicate high spin 6-coordinate octahedral geometry for all the complexes. ESR spectral studies on copper(II) complexes in solid state show a tetragonal octahedral environment around the metal ion and as the ground state. IR studies suggest that uracil behaves as monobasic bidentate ligand bonding through N(1) and C(4)=O groups to different metal atoms forming a polymeric framework. The ligand Bh bonds to metal through –NH2 and >C=O groups while Inh through –NH2 and a deprotonated C–O− groups. TGA studies of some of the complexes show multi-step decomposition pattern of their organic frameworks.