Stabilisation of the [SiH₆]^2- Anion within a Supramolecular Assembly

The hypercoordinate [SiH6](2-) anion is not stable in solution. Here, we report the room temperature, solution stable molecular [SiH6](2-) complex, [{KCa(NON)(OEt2)}(2)][SiH6] (NON=4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethyl-xanthene)), where the [SiH6](2-) anion is stabilised within a supramolecular assembly that mimics the solid-state environment of the anion in the lattice of K2SiH6. Solution-state reactivity of the complex towards carbon monoxide, benzaldehyde, azobenzene and acetonitrile is reported, yielding a range of reduction and C-C coupled products.