The isoelectronic series of alanes [R3Al] and silylium cations [R3Si]+ has now been extended with the synthesis and characterization of two phosphorandiylium dications ([R3P]2+), which are trigonal planar Lewis superacids. The electrophilicity at the phosphorus atom is governed by the π-electron-donating ability of the attached N-heterocyclic imine substituents.
- Paul Mehlmann
- Tim Witteler
- Fabian Dielmann