Ruthenium(III) Schiff base chloro and carbonyl complexes: synthesis, characterization and EPR studies

Abstract

The synthesis and characterization of stable ruthenium(III) Schiff base chloro and carbonyl complexes with the axial ligands chloro (Cl), imidazole (Im) and 2-methylimidazole (2-MeIm) are reported. The Schiff bases were synthesized by the interaction of naphthaldehyde with amines such as o-phenylenediamine, ethylenediamine, propylenediamine and diethylenetriamine. The geometry around ruthenium in these complexes is psuedooctahedral. The complexes are low-spin 4d⁵ (S=½) and display characteristic EPR spectra in the powder samples and in frozen solutions at 298 and 77 K. The EPR data and EHMO calculations on model complexes indicate that the d_xy orbital lies above d_xz and d_yz orbitals.