The high reactive site and the unusually short Sc‐C bond of the scandium phosphinoalkylidene complex, an explanation from first‐principles calculation

Abstract

The recently synthesized first scandium phosphinoalkylidene complex has attracted extensive attentions for its high chemical activity around the unusually short Sc‐C bond. Here, we report our studies on this issue by using the first‐principles method. Our analyses establish a triple‐bond picture, d‐p (π, σ, σ), for the short Sc‐C bonding interactions. The calculated valence Bader charge shows that the specific C atom on the Sc‐C bond is highly charged, which makes the C atom on the Sc‐C bond an active nucleophilic site for the attack of Lewis acids. On the other hand, the Sc atom is shown to be an electrophilic site and thus vulnerable to the attack of Lewis bases due to the empty Sc‐3d yz/xz orbitals on the LUMO band. Our studies reveal the origin for the short Sc‐C bond and the high reactivity occurring around the Sc‐C bond. Our molecular calculations give consistent results with the solid calculations.