The influence of varying concentrations of Co(dmgh)₂, NaOH and axial base on the rate of hydrogenation of fumaric and maleic acids has been studied in detail. Intramolecular hydrogen bonding in the monoanion of maleic acid and thetrans orientation of carboxylic acid groups in fumaric acid are important factors which account for the difference in the rate of hydrogenation of these substrates. Mono-, di-and trialkyl amines as axial bases modify the activity of the catalyst, dialkylamines conferring the maximum activity and trialkylamines the least. Back-strain on nitrogen atom and solvation energy of the amines are responsible for their different behaviours. A rate law has been proposed and verified

Ruthenium(III) catalysed oxidation of 1-phenylethanol and substituted 1-phenylethanols by phenyliodosoacetate (pia) in acetic acid is studied and a probable mechanism suggested. The proposed mechanism involves the formation of a complex of Ru(III) and (pia) which reacts with the substrate, S, in a slow step. Spectrophotometric evidence for this complex is presented. Studies on the effect of substituents suggest a transition state involving a π-complex.

Catalytic amounts of RuCl₂(PPh₃)₃ in the presence of excess of N-methylmorpholine N-oxide (NMO) in DMF, oxidizes secondary alcohols to ketones. Spectral and electrochemical studies reveal the formation of an oxocomplex of Ru(IV), on adding excess of NMO. In the proposed mechanism, the Ru(IV)-oxo complex formed from Ru(II) and NMO, attacks the substrate in the rate determining step.

Rate constants for the reaction of phosphate radical with some aromatic and aliphatic amines have been determined by the flash photolysis technique. The products formed under conditions of continuous irradiation have been identified. In the case of an aromatic amine the major product is the azo compound while in the case of an aliphatic amine a carbonyl compound is formed.

The selective oxidation of thioethers to sulphoxides and of PPh₃ to PPh₃O can be effected by NMO in DMF as solvent in the presence of Ru(III) chloride as catalyst. Kinetic investigations indicate that the orders with respect to the catalyst and oxidant are one each. The order with respect to the substrate is variable being fractional order at low concentrations and zero at high concentrations. Spectrophotometric studies reveal the formation of a 1:1 complex between the substrate and the catalyst. A mechanism consistent with the above observations has been proposed and verified.

The borate radical is produced by the flash photolysis of an aqueous alkaline solution of NaBO₂ and K₂S₂O₈. The absorption spectrum of the transient borate radical shows two maxima. The self decay of this radical is second order. Rate constants for the reactions of this radical with some organic substrates have been determined.