Base-Stabilized [PO]+ /[PO2 ]+ Cations.

The salts [(BAC)2 PO][BF4 ] (5) and [(BAC)2 PO2 ][BF4 ] (4) (BAC=bis(diisopropylamino) cyclopropenylidene), consisting of the PO+ and PO2 + cations, respectively, coordinated to the singlet carbenes, have been prepared. Computational investigations reveal that the electronic structure of the PO+ cation is a hybrid between the charge-localized and charge-delocalized resonance forms, resulting in ambiphilic reactivity. Compound 5 reacts as a donor with the transition-metal complex K2 PtCl4 to furnish [[(BAC)2 PO]2 PtCl2 ][BF4 ]2 (6) and KCl. Remarkably, both 5 and 4 have shown to act as electrophiles undergoing reactions with fluoride anion, leading to [OPF2 ]- and (BAC)PO2 F, respectively.