Synthesis, spectral and thermal aspect of transition metal coordination polymers with bis-hydrazone ligand

Abstract

A few coordination polymeric assemblies of the type {[M(dddinh)(H2O)2].xH2O}n (where M = Mn(II), Ni(II), and Cu(II), x = 2; and Co(II), x = 0, with (N′,N″E,N′,N″E)-N′,N″-(1,2-diphenylethane-1,2diylidene) diisonicotino-hydrazide (dddinh)) have been synthesized and characterized by using various spectroscopic techniques such as elemental analysis, Fourier transform infrared (FTIR), diffuse reflectance spectra, magnetic measurements and thermo gravimetric analysis. Magnetic moment and reflectance spectral studies reveal that an octahedral geometry was assigned to all the prepared coordination polymers. Each metal ion is coordinated by a bis (bidentate) manner through oxygen atom of carbonyl group and the nitrogen atom of amide group of ligand and two aqua ligands by coordinated bond which formed five-member heterocyclic ring. The decomposition steps and thermal stability of these coordination polymers were studied by using thermal analysis techniques. The thermal stabilities of coordination polymers are explained on the basis of release of coordinated water and decomposition of backbone structure (ligand). The thermal studies inferred the presence of crystallized water in all coordination polymers except Co(II), whereas coordinated water was found in all polymers.