Simple access to ionic liquids and organic salts containing the phosphaethynolate (PCO(-)) and Zintl (Sb11(3-)) anions.

Herein we report the synthesis of the first ionic liquids with the highly reactive and synthetically valuable phosphaethynolate (PCO(-)) anion. They are simply synthesised by the reaction of organic methylcarbonate salts with P(SiMe3)3. The products are obtained in near to quantitative yields and they are highly viscous liquids at room temperature or have low melting points for symmetric cations. Moreover, extending this synthetic strategy towards Sb(SiMe3)3 we discovered a simple synthesis for [P(nBu)3Me](+)3[Sb11](3-), the first organic cation salt comprising the Zintl-anion [Sb11](3-).