G. Bellachioma et al., EQUILIBRIUM-CONSTANTS AND KINETICS OF CARBON-MONOXIDE INSERTION IN ALKYL COMPLEXES OF RUTHENIUM(II), Journal of organometallic chemistry, 540(1-2), 1997, pp. 7-13
The equilibrium constants of the reaction of cis, trans-[Ru(CO)(2)(PMe
3)(2)(CH3)I] (Me) with carbon monoxide to give cis, trans-[Ru(CO)(2)(P
Me3)(2)(COMe)I] (Ac) and trans, trans-[Ru(CO)(2)(PMe3)(2)(COMe)I] (At)
were measured at various temperatures in toluene. The thermodynamic p
arameters are compared with those obtained for the isoelectronic compl
exes of iron, and the trend is discussed. The kinetics of the carbonyl
ation reaction of Me, as well as those of the inverse decarbonylation
reaction of At were measured. The kinetics of the carbonylation of the
new complex trans, trans-[Ru(CO)(2)(PMe3)(2)(CH3)I] (Mt) were also in
vestigated. All the results afford further support to the previously p
roposed CO insertion mechanism occurring via methyl migration. The com
parison of these kinetic results with those of isoelectronic complexes
of iron indicates that ruthenium is more reactive than iron, which is
reflected by its greater aptitude to act as catalyst in many processe
s. (C) 1997 Elsevier Science S.A.