Oxidative addition of the C-S bond of thiophene to the (C5Me5)Rh(PMe3) fragment:: A theoretical study revisited

Density functional theory (DFT) calculations on the C-S bond activation reaction of thiophene with the [(C5Me5)Rh(PMe3)] fragment have been reinvestigated, giving two new isomeric C-S bond activation transition states, in which the coordinated thiophene molecule tilts toward either the C5Me5 ligand or the PMe3 ligand. Through intrinsic reaction coordinate (IRC) calculations, these transition states were found to connect the oxidative addition product with two isomeric eta(2)-C,S coordinated intermediates. These latter intermediates in turn connected to two isomeric eta(1)-S and eta(2)-C,C coordinated species. The energetics and mechanistic details are described.