Synthesis and physico-chemical and biological studies on ruthenium (III) complexes with Schiff bases derived from aminocarboxylic acids

Ruthenium(III) complexes of types [Ru(L)₃], [Ru(L′)Cl(H₂O)₂], [Ru(L″)Cl₂]_n, [Ru(L‴)Cl(H₂O)]_n(LH =Schiff bases derived from anthranilic acid and benzaldehyde, acetophenone, vanillin, cinnamaldehyde or m-hydroxyacetophenone; L′H₂=Schiff bases derived from anthranilic acid and salicylaldehyde or o-hydroxyacetophenone; L″H=Schiff bases derived from p-aminobenzoic acid and benzaldehyde, acetophenone, vanillin, cinnamaldehyde or m-hydroxyacetophenone; L‴H₂=Schiff bases derived from p-aminobenzoic acid and salicylaldehyde or o-hydroxyacetophenone) have been synthesized and characterized on the basis of elemental analyses, conductance, magnetic moment and spectral (electronic, i.r. and¹H n.m.r.) data. The wavelengths of the principal electronic absorption peaks have been accounted for quantitatively in terms of crystal field theory and various parameters have been evaluated. On the basis of the electronic spectra, an octahedral geometry has been established for all these complexes except [Ru(L″)Cl₂]_n. The complexes [Ru(L″)Cl₂]_n are pentacoordinate and a trigonal-bipyramidal environment, D_3h, is suggested for the ruthenium(III) ion. The thermal behaviour of these complexes has also been studied by t.g., d.t.g and d.s.c techniques. Heats of reaction for the decomposition steps were calculated from the d.s.c. curves. The antifungal and antiviral activities of the complexes with Schiff bases derived from anthranilic acid were also investigated.