Experimental study of the gas phase chemistry of C3H3+ with several cyclic molecules

Rate coefficients and ion product distributions have been determined for the gas phase reactions of C₃H₃⁺ with several homocyclic and heterocyclic molecules in a selected ion flow tube (SIFT) at 298 K. The rate coefficients for both the linear and cyclic isomers of C₃H₃⁺ are given. l-C₃H₃⁺ reacts by association in the majority of the reactions. c-C₃H₃⁺ is shown to be more reactive than previously suggested by low pressure experiments. In fact, the cyclic isomer reacts at the gas kinetic rate when the reaction involves a nitrogen containing cyclic compound but is less reactive with oxygen containing cyclic compounds. It is noted this reactivity of both the cyclic and linear isomer should be included when modeling the atmosphere of Titan due to the large number of nitrogen containing molecules that are considered to be present. Currently, the models consider electron recombination to be the only loss channel for c-C₃H₃⁺.