121808-99-9Relevant articles and documents
Systematic substituent effects on dissociative substitution kinetics of Ru(CO)4L complexes (L = P-, As-, and Sb-donor ligands)
Chen, Lezhan,Po?, Anthony J.
, p. 3641 - 3647 (2008/10/08)
The kinetics of dissociation of CO from Ru(CO)4L (L = a wide variety of P-, As-, and Sb-donor ligands) have been studied, and the values of the rate constants can be resolved quantitatively into electronic and steric effects. The curved steric profile obtained shows that steric effects are quite small for small substituents such as P(OCH2)3CEt and P(OEt)3, but they increase steadily and substantially as the size of the substituent increases. A similar analysis of data in the literature for CO dissociative reactions of other substituted carbonyl complexes is also successful in resolving electronic and steric effects, and a clear dependence of steric effects on the coordination number of the complexes is shown. The analysis can be applied to some methyl migration reactions that involve CO loss, and the results can help to indicate the relative importance of CO loss and methyl migration in the transition states. Trends in the C-O stretching frequencies in the axial Ru(CO)4L and diaxial Ru(CO)3L2 complexes are described.
