Kinetics and mechanism of carbon disulfide insertion into the Ru H bond in CpRu(PAr3)2H (Ar = Ph, p-tolyl, p-anisyl)

The insertion of carbon disulfide into the Ru H bond of CpRu(PAr 3 ) 2 H (Ar 3 = Ph 3 , 1 , Ph 2 (p-tolyl), 2 , (p-tolyl) 3 , 3 , and (p-anisyl) 3 , 4 ) in C 6 D 6 is first order in each reactant and second order overall. The relative rate of reaction is 4 ≈ 3 > 2 > 1 suggests that a stronger σ-donor ligand increases the hydridicity of the Ru H bond and increases the rate of insertion. Activation parameters were measured for the reaction of 1 with CS 2 as ∆H † = 70 ± 1 kJ/mol and ∆S † = −25.9 ± 0.2 J/mol-K. • The kinetics of CS 2 insertion into the Ru H bond of CpRu(PAr 3 ) 2 H where Ar = phenyl ( 1 ), p-tolyl ( 2 ) and p-anisyl ( 3 ) are reported. • The second order reaction appears to proceed by an outer sphere pathway without dissociation of PAr 3 .