Mass spectrometry of organic compounds in the group V elements—II: Branched chain aliphatic derivatives

The behaviour of compounds I to XII under electron-impact (electron voltages 30 and 12 eV) was investigated. The abundance of the ions characteristic of amines was shown to decrease drastically with an increase of chain branching in alkylphosphines. Comparison of the spectra of VII and X led to the conclusion that the unshared electron pair of phosphorus does not affect the fragmentation. The main peaks in the spectra of phosphines corresponded to hydrocarbon fragments. The origins of the main fragment ions were confirmed by metastable peaks.