IPr3 Si3 Cl5 (+) : A Highly Reactive Cation with Silanide Character.
The reaction of a metastable SiCl2 solution with the sterically less-demanding carbene N,N-diisopropylimidazo-2-ylidene (IPr) yields the salt [(IPr3 Si3 Cl5 )(+) ]Cl(-) (1-Cl), containing a silyl cation with a Si3 backbone. Salt 1 is highly reactive, but it can be used as a reagent in deuterated dichloromethane, whereby dehalogenation with Me3 SiOTf (OTf=O3 SCF3 ) gives the dicationic silyl halide [(IPr3 Si3 Cl4 )](2+) 2. Quantum chemical calculations show that the HOMO is localized at the negatively charged central silicon atom of 1 and 2, and thus although both compounds are cations they are better described as silanides, which was also corroborated by NMR investigations.
Institute of Inorganic Chemistry, University Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.
Fabian
F
Uhlemann
Institute of Inorganic Chemistry, University Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany. andreas.schnepf@uni-tuebingen.de.
Andreas
A
Schnepf
density functional calculations; main-group chemistry; silanides; silicon; structure elucidation