Characterization of isomeric [CH5P]+˙ and [C2H7P]+˙ radical cations and some [C2H6P]+ phosphonium ions in the gas phase by their collisional activation spectra

Abstract Collisional activation spectra were used to characterize isomeric ion structures for [CH 5 P] +˙ and [C 2 H 7 P] +˙ radical cations and [C 2 H 6 P] + even‐electron ions. Apart from ionized methylphosphane, [CH 3 PH 2 ] +˙ , ions of structure [CH 2 PH 3 ] +˙ appear to be stable in the gas phase. Among the isomeric [C 2 H 7 P] +˙ ions stable ion structures [CH 2 PH 2 CH 3 ] +˙ and [CH 2 CH 2 PH 3 ] +˙ /[CH 3 CHPH 3 ] +˙ are proposed as being generated by appropriate dissociative ionization reactions of alkyl phosphanes. At least three isomeric [C 2 H 6 ] + ions appear to exist, of which $$ {\rm CH}_{\rm 3} - \mathop {\rm P}\limits^{\rm + } {\rm H = CH}_{\rm 2} $$ could be identified positively.