Gas-phase ion chemistries in perfluoromethylcyclohexane

Electron impact ionization and ion-molecule reactions of perfluoromethylcyclohexane (C(7)F(14)) using Fourier-transfer mass spectrometry are reported. The electron impact ionization produces dominant ions CF(3)(+) and C(3)F(5)(+) throughout most of the energy range of 10-200 eV, with the total ionization cross section peaking at similar to 100 eV with a value of 1.8 x 10(-15) cm(2). Numerous ions are observed at energies within a few electron volts of the lowest ionization threshold: CF(3)(+), C(2)F(4)(+), C(3)F(4,5,)(+) C(4)F(5-7,)(+) C(5)F(9)(+), C(6)F(9-11)(+) and C(7)F(13)(+). The lighter ions CF(+), CF(2)(+) and CF(3)(+) are found to react with C(7)F(14) forming C(7)F(13)(+) and other product ions that we believe to result from further fragmentation of the intermediate ion C(7)F(13)(+). The charge transfer reaction between Ar(+) and C(4)F(14) yields similar product ions.