Synthesis, Physicochemical and Thermal Analyses of Ru(III), Pt(IV), and Ir(III) Complexes with NO Bidentate Schiff Base Ligand

Abstract

The chemical reaction of the 2-[(2,3-dihydroxybenzylidene)amino]benzoic acid (H₃L²) Schiff base ligand with Ru(III), Pt(IV) and Ir(III) transition metal ions form the complexes of formula, [Ru(L)(Cl)₂(NH₃)₂(NH₄)₂] · 2H₂O (1), [Pt(L)(Cl)₃(NH₃)(NH₄)₂] · H₂O (2), and [Ir(L)(Cl)₂(NH₃)₂(NH₄)₂](3), where L is deprotonated ligand at pH 8–9. The carboxylic acid group is deprotonated and forms ammonium carboxylates at alkaline media. The infrared spectra of the complexes show that Schiff base ligand is present as a NO bidentate chelate through –N atom of azomethine and –O atom of OH phenolic groups. These complexes are of non-electrolyte nature. The electronic spectra and magnetic moments data suggest the coordination number. Thermo gravimetric studies show that ruthenium(III) and platinum(IV) complexes containing hydrated water molecules outside the coordination sphere that are presence on their thermal decomposition in the temperature range 50–100°C. Solid powder diffraction XRD patterns of complexes show isomorphism confirming their similar formulation. Scanning electron microscopy (SEM) micrographs of the complexes samples confirm the surface homogeneity. In the transmission electron microscopy (TEM) pictures these complexes are present as a dark spots with particle size of 50 nm.