Simulations of ethylene insertion in the PtII-H bond of (H)Pt(PX3)2+ species

Hartree-Fock, MP2, DFT, and Car-Parrinello type molecular dynamics simulations are reported applied to the insertion of ethylene in cationic platinum-hydrido-diphosphine complexes. The barrier to insertion is found to be small to negligible, which suggests that the insertion step itself is not rate-determining in a variety of catalytic processes including polymerization reactions, olefin isomerizations, hydroformylations, and hydrogenation reactions. The variation of the P-Pt-P bond angle throughout the reaction is found to be small, indicating that the complex can be relatively rigid while still allowing the insertion reaction to proceed. The energetics of the insertion reaction are hardly affected by electron-withdrawing or electron-donating groups on the phosphorus ligands (PH3, PCl3, PMe3).