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Complexes of the type [Ru(CO)(EPh3)(B)(L)] (E = P or As; B = PPh3, AsPh3, py or pip; L = dianion of the Schiff bases derived from the condensation of salicyloyl hydrazide with acetone, ethyl methyl ketone and salicylaldehyde have been synthesised by the reaction of equimolar amounts of [RuHCl(CO)(EPh3)2(B)] and Schiff bases in benzene. The resulting complexes have been characterized by analytical and spectral (i.r., electronic, n.m.r.) data. The arrangements of Ph3P groups around the Ru metal was determined from 31P-n.m.r. spectra. An octahedral structure has been assigned to all the new complexes. All the complexes exhibit catalytic activity for the oxidation of benzyl alcohol and cyclohexanol in the presence of N-methylmorpholine-N-oxide as co-oxidant.

The synthesis and characterisation of some new hexa-coordinated Schiff base complexes of the type [RuCl(CO)(EPh3)(B)(L)] (E = P or As; B = PPh3 or AsPh3 or py or pip; L = anion of the Schiff bases derived from 2-hydroxy-1-naphthaldehyde and aniline, 4-chloroaniline or 2-methylaniline) are reported. I.r., electronic, 1H-n.m.r, 31P-n.m.r. spectra, catalytic activity and antibacterial activity of the complexes are discussed. An octahedral structure has been tentatively proposed for all the complexes.

Hexacoordinated binuclear ruthenium(III) complexes of the type {[RuX2(EPh3)2]2(bis-β-dk)} [X = Cl or Br; bis-β-dk = thiobis(β-diketone)] have been prepared by reacting [RuCl3(PPh3)3], [RuCl3(AsPh3)3], [RuBr3(AsPh3)3] or [RuBr3(PPh3)2(MeOH)] with thiobis(β-diketones) in a 2:1 molar ratio in benzene, and characterized by analytical, spectroscopic (i.r., electronic e.p.r.) and cyclic voltammetric data. An octahedral structure has been proposed. The complexes are effective catalysts for the oxidation of PhCH2OH and cyclohexanol to PhCHO and cyclohexanone respectively using N-methylmorpholine-N-oxide as co-oxidant. Some of the complexes have been subjected to antifungal activity studies.

Binuclear ruthenium(III) complexes containing a binucleating Schiff base ligand, L and Ph3P or Ph3As, [RuX2(EPh3)2]2L (X = Cl or Br; E = P or As) have been prepared by reacting [RuCl3(PPh3)3], [RuCl3(AsPh3)3], [RuBr3(AsPh3)3] and [RuBr3(PPh3)2(MeOH)] with Schiff bases in a 2:1 molar ratio. The Schiff bases used in this study were prepared by condensing the appropriate diamine with salicylaldehyde or benzoylacetone in a 1:2 molar ratio respectively. The complexes were characterised by analytical, spectral (i.r., electronic, e.p.r.) and electrochemical data. An octahedral structure has been proposed for all the new ligand-bridged binuclear RuIII complexes. The new complexes have been used as catalysts in aryl–aryl couplings and also subjected to antifungal activity studies.

Hexa-coordinated ruthenium(II) complexes of the type [Ru(CO)(PPh3)(Z)(L)] [Z = PPh3, pyridine (py) or piperidine (pip); L = anion of the Schiff base] have been prepared by reacting [RuHCl(CO)(PPh3)2(Z)] with tridentate Schiff bases derived by condensing anthranilic acid with acetylacetone, salicylaldehyde, o-vanillin and o-hydroxyacetophenone. The complexes were characterised by analytical and spectral (i.r., electronic, 1H- and 31P-n.m.r.) data, and were found to be effective catalysts for oxidising primary alcohols to aldehydes in the presence of N-methylmorpholine-N-oxide (NMO) as co-oxidant. The Schiff bases and their ruthenium(II) complexes show growth inhibitory activity against pathogenic fungi Aspergillus flavus, Fusarium oxysporium and Rhizoctonia solani.