Kinetic study on the interconversion between (silylacetylene)- and (β-silylvinylidene)rhodium(I) complexes

Article abstract of DOI:10.1021/om9603575

Kinetic studies on the interconversion between trans-RhCl(FcC≡CSiMe₃)(PPrⁱ₃)₂ (2a) and trans-RhCl-{=C=C(Fc)(SiMe₃)}(PPrⁱ₃)₂ (Ba) (Fc = ferrocenyl group) provided the following activation parameters for the forward and the backward reactions: ΔH^? = 19.8 ± 0.2 kcal mol^-1 and ΔS^? = -4.8 ± 0.7 eu for 2a to 3a and ΔH^? = 22.7 ± 0.1 kcal mol^-1 and ΔS^? = -8.6 ± 0.4 eu for 3a to 2a. The values are consistent with the isomerization mechanism via a sigmatropic 1,2-migration of the SiMe₃ group.