Kinetics of associative reactions of Ru3(CO)10(μ-dppm)

The kinetics of reactions of some more basic P-donor ligands with Ru 3 (CO) 10 (μ-dppm) have been studied and shown to include an associative term. Electronic and steric effects due to different attacking nucleophiles can be separated. The sensitivity of Ru 3 (CO) 10 (μ-dppm) to the basicity of the nucleophiles is slightly greater than that of Ru 3 (CO) 12 but the former is considerably more susceptible to steric effects. The intrinsic susceptibility of Ru 3 (CO) 10 ,(μ-dppm) to nucleophilic attack is defined and shown to be similar to that of Ru 3 (CO) 12 . Activation parameters show, however, that this is due to the combination of a much more favourable activation enthalpy balanced by a much more unfavourable activation entropy. The implications of these results are discussed.