Synthesis and physicochemical studies of polymeric coordination complexes of some lanthanides with 1,4-dihydroxyanthraquinone

Abstract

Coordination polymers of lanthanum(III), praseodymium(III), neodymium(III), samarium(III), dysprosium(III) and holmium(III) with 1,4-dihydroxyanthraquinone have been synthesized and characterised. Their magnetic moments, infrared spectra and electronic spectra have been studied to establish their structure. All the polychelates are amorphous, dark coloured powders, insoluble in common organic solvents and sparingly soluble in dimethylformamide. Nephelauxetic ratio (β), covalency factor ( b 1/2), etc. have been evaluated wherever possible. Thermogravimetric studies (TGA) indicate a higher decomposition temperature of polychelates than the parent ligand. A.c.-conductivity, dielectric constant (ϵ′), dielectric loss (ϵ″), all at various frequencies, as well as d.c.-conductivity of the prepared polychelates, are reported. The analytical data are suggestive of a 2:3 metal-ligand stoichiometry in the polychelates.