Silyliumylidene Ion Stabilized by Two σ‐Donating Ni(0)‐ and Pd(0)‐Fragments

Abstract

A silyliumylidene ion 2 stabilized by two σ‐donating Ni(0)‐ and Pd(0)‐fragments was successfully synthesized. Due to the σ‐donation of M→Si interactions, 2 presents a pyramidalized cationic silicon center with a localized lone pair. The additional coordination of basic Pd(0) fragment to the mono‐Ni(0)‐stabilized silyliumylidene 1 results in a higher HOMO level and an unchanged HOMO‐LUMO gap and thus, 2 remains highly reactive. Interestingly, the coordination mode at the Si center is closely related to the nature of M‐ligands. Indeed, the donor/donor‐stabilized silyliumylidene ion 2 has been transformed into a donor/acceptor‐stabilized ion 13, featuring a trigonal planar Si center with a vacant orbital, just via a ligand exchange reaction from PCy3/NHC toward PMe3.