Positive ion–molecule reactions in OCS/hydrocarbon mixtures

The positive ion–molecule reactions of OCS have been investigated in an ion cyclotron resonance spectrometer. A variety of reactions in OCS/hydrocarbon mixtures have been investigated for various C1C4 hydrocarbons—alkanes, alkenes and alkynes. The formation of organosulfur ions is found in reactions in OCS/hydrocarbon (Cn) mixtures with n <4. Formation of organosulfur ions is observed from hydrocarbon ions reacting with OCS and [OCS]+˙ and S+˙ reacting with the hydrocarbons. The proton affinity of OCS has been determined to be 688.7±8 kJ mol−1 while that of CS2 is measured to be 712.1±8 kJ mol−1. Comparison with the proton affinity of CO2 shows that the proton affinity increases as sulfur is substituted for oxygen.