Polymer complexes: XLIX—Supramolecular modeling of bonding in novel rare earth polymeric rhodanine drug complexes

Novel supramolecular rare earth polymeric hydrazone complexes of 5-sulphadiazineazo-3-phenyl-2-thiaxo-4-thiazolidinone (HL) of the composition (Ln)₂(HL)₃(NO₃)₆]_n (where Ln = La(1), Y(2), Pr(3), Nd(4), Sm(5), Gd(6) and Ho(7)) have been prepared and characterized on the basis of their chemical analyses, magnetic measurements, conductance, visible and IR spectral data. Composition, conductance and IR spectral data of complexes show that all these act as a tetradentate ligand. Electronic spectra indicate weak covalent character in the metal–ligand bond. The spectra of Nd³⁺ and Ho³⁺ show characteristic f–f transitions and the metal–ligand covalency in % has been evaluated. The spectral properties of the above polymeric complexes are also discussed.