Ion—molecule reactions in mixtures of CS 2 with H 2 and CH 4

Abstract

CS 2H + and CSH + ions are the most significant secondary ions found in mixtures of CS 2 with H 2 and CH 4 at pressures of about 10 −3 Nm −2 in an ion cyclotron resonance mass spectrometer. The CS 2 + primary ions are unreactive and CS 2H + ions are formed by reactions of H 2 + and CH 4 + only, the rate constants of which are very much less than the theoretical values, due perhaps to the interference of charge transfer reactions. Double resonance experiments of CS 2/CH 4 and CS 2/C 2H 6 mixtures indicate that the limits for the heat of formation of CS 2H + are 1037 kJ mole −1 < Δ H f(CS 2H +) < 1124 kJ mole −1. CSH + ions are formed by reactions of CS + only. Small amounts of CH 3S + and CH 3CS + are formed from CH 3 +. In CS 2 alone, CS 2 + ions with kinetic energies of at least 1.7 and 2.6 eV form C 2S 2 + and CS 3 + ions, respectively.