Lewis Acid Decorated Hexacyanodiborane(6) Dianion.

First examples of diborane(6) dianions decorated with weakly coordination B(CF) (BCF) groups and SiEt moieties have been synthesized demonstrating the synthetic potential of the [B(CN)] dianion. [B{CNB(CF)}] (1) was isolated as potassium and tetrabutylammonium salt. 1 is a rare example for a weakly coordinating dianion and it was used for the stabilization of the carbocation [PhC] and the oxonium acid [H(OEt)]. Reaction of [PhC]1 with HSiEt resulted in the silylated neutral diborane(6) [B{CNB(CF)}(CNSiEt)] (2) in which two BCF groups have been selectively replaced by SiEt substituents, underscoring the stability and chemical versatility of the [B(CN)] dianion. The chemical properties and physicochemical data of 1 and 2 provide insight into electronic, coordinating, and steric properties of theses novel diborane(6) compounds.