The mass spectra of some para substituted triarylphosphines and triarylphosphine oxides

The mass spectra are reported for a series of tris(p-alkylaryl)phosphines and the corresponding phosphine oxides. The phosphines all give M]^+˙ as the base peak except when the phenyl groups are not para substituted. For the oxides M–H]⁺ gives the base peak with one exception for which M]^+˙ is the most abundant ion.