Polymer complexes. XLXI. Supramolecular spectral studies on metal–ligand bonding of novel rhodanine sulphadrugs hydrazone

Abstract

Novel polymeric complexes with 5-sulphadiazineazo-3-phenyl-2-thioxo-4-thiazolidine (HL 1), 5-sulphamethazineazo-3-phenyl-2-thioxo-4-thiazolidine (HL 2) and 5-sulphamethoxazoleazo-3-phenyl-2-thioxo-4-thiazolidine (HL 3) and various anions were prepared. Structural and spectroscopic properties have been studied on the basis of elemental analyses, infrared spectra, 1HNMR spectra, electronic spectra, magnetic measurements and ESR. IR and 1H NMR studies reveal that the ligands (HL n ) exists in the tautomeric enol/hydrazo form in both states with intramolecular hydrogen bonding. The analytical data and the molar conductance measurements of the polymeric complexes reveal that three molecules of the ligand and four/two(Cl/SO 4) of the anions are coordinated to the two metal atoms in all complexes. The infrared spectra of the ligands and their polymeric complexes, confirmed that the ligands coordinate to Cu(II) as a neutral and tetradentate via NH(hydrazone), oxygen of the carbonyl group (CO), nitrogen of the NH(3-phenylamine) and thion sulphur (CS) group. All the polymer complexes were found to have magnetic moments corresponding to one unpaired electrons. The ESR ( g || and g ⊥) and bonding α 2 parameters of the copper ion were greatly affected by substituting several groups position of ring of sulphadrug. The ESR spectra of copper complexes in powder form show a broad signal with values in order g || > g ⊥ > g e (2.0023). The value of covalency factor β and orbital reduction factor K accounts for the covalent nature of the complexes.