A density functional study on the activation of hydrogen-hydrogen and hydrogen-carbon bonds by Cp2Sc-H and Cp2Sc-CH3

Density functional calculations have been carried out on Cp 2 Sc-R (R=H, methyl, ethyl, propyl, vinyl, and acetylide). Geometry optimizations reveal an agostic interaction for R=ethyl, whereasmethyl and propyl are bound to the metal center without agostic interactions. The Sc-R bond energies are calculated as D e (Sc-acetylide)=540 kJ mol -1 >D e (Sc-H)=340 >D e (Sc-vinyl)=338>D e (Sc-methyl)=295>D e (Sc-ethyl)=283> D e (Sc-propyl)=240