Supramolecular modeling in novel polymeric complexes of ruthenium and uranium derived from azoquinoline containing hydrogen bonds

Abstract

Novel polymeric complexes of Ru3+ and with 5-(2−-alkyl phenylazo)-8-quinolinol (LnH2) have been prepared and characterized by elemental and thermogravimetric analysis (TGA), 1H and 13C NMR, magnetic susceptibility and electronic spectral techniques. The important infrared (IR) bands and the main 1H and 13C NMR signals are assigned and discussed relative to the proposed molecular structure of the polymeric complexes. The spectra show that all complexes are octahedral with chloride attached to the metal. The spectral data were utilized to compute the important ligand field parameters B, β and Dq. The B-values suggest covalency in the metal-ligand σ-bond and the Dq-values indicate a medium strong ligand field. β depends greatly on the electronegativity of the donor atoms and the ligand structure and also the effect of the o-substituent groups. The ligands are dibasic (bis-bidentate chelating agent), coordinating through CN, N=N, COOH, OH and SH groups by replacement of a proton from the last three groups. The bond lengths and the force constants of the U–O bond were calculated from the IR data related to the electronic properties of the substituents. Considerable interest has been focused on the synthesis of azo compounds and polymeric metal complexes. The stability of these complexes has also been investigated. O-azo-quinolinols intramolecular OH–N hydrogen bonds have been detected and discussed.