Synthesis, characterization and 3D molecular modeling of some ternary complexes of Cu(II), Ni(II), Co(II), Zn(II), Sm(III), Th(IV) and UO₂(VI) with Schiff base derived from the sulfa drug sulfabenzamide and 1,10-phenanthroline

Abstract

Some new mixed-ligand ternary complexes of Cu(II), Ni(II), Co(II), Zn(II), Sm(III), Th(IV) and UO₂(VI) with the Schiff base derived from salicylaldehyde and the sulfa drug sulfabenzamide, [N-(salicylidene)sulfabenzamide] (LH) and the heterocyclic base 1,10-phenanthroline (phen) have been synthesized and characterized by IR, NMR, diffuse reflectance spectra, and thermal, magnetic and molar conductance measurements. Thermal analyses indicate the presence of lattice and coordinated water molecules in the complexes, which is also supported by the IR spectral data. The coordination by the azomethine nitrogen is inferred by the upfield shifting of the –CH=N– signal in the NMR spectra and the shift of ν(C=N) to lower wave numbers in the IR spectra upon complexation. The Schiff base ligand (LH) acts as a monobasic bidentate ligand in complex formation. The presence of anion, viz., CH₃COO⁻ or NO₃⁻ in the coordination sphere is also inferred by the IR spectral data and conductance measurements. The general compositions of the complexes are found to be [M(L)(phen)(OAc)(H₂O)], where M = Cu(II), Ni(II), Co(II), Zn(II) or UO₂(VI), [Sm(L)(phen)(OAc)₂(H₂O)₂].H₂O and [Th(L)(phen)(NO₃)₃(H₂O)].4H₂O, where AcOH = acetic acid and LH = [N-(salicylidene)sulfabenzamide].