Triphenylmethyl hexafluorophosphate

Triphenylmethyl hexafluorophosphate (also triphenylcarbenium hexafluorophosphate, trityl hexafluorophosphate, or tritylium hexafluorophosphate) is an organic salt with the formula [(C6H5)3C]+[PF6]−, consisting of the triphenylcarbenium cation [(C6H5)3C]+ and the hexafluorophosphate anion [PF6]−.

Triphenylmethyl hexafluorophosphate is a brown powder that hydrolyzes readily to triphenylmethanol. It is used as a catalyst and reagent in organic syntheses.

Preparation
Triphenylmethyl hexafluorophosphate can be prepared by combining silver hexafluorophosphate with triphenylmethyl chloride:


 * Ag+[PF6]− + (C6H5)3CCl → [(C6H5)3C]+[PF6]− + AgCl

A second method involves protonolysis of triphenylmethanol:


 * H[PF6] + (C6H5)3COH → [(C6H5)3C]+[PF6]− + H2O

Structure and reactions
Triphenylmethyl hexafluorophosphate readily hydrolyzes, in a reaction that is the reverse of one of its syntheses:


 * [(C6H5)3C]+[PF6]− + H2O → (C6H5)3COH + H[PF6]

Triphenylmethyl hexafluorophosphate has been used for abstracting hydride from organic compounds. Treatment of metal-alkene and diene complexes one can generate allyl and pentadienyl complexes, respectively.

Triphenylmethyl perchlorate is a common substitute for triphenylmethyl hexafluorophosphate. However, the perchlorate is not used as widely, because, like other organic perchlorates, it is potentially explosive.