Ion-molecule reactions relevant to Titan's ionosphere

Abstract

Twenty four new ion-molecule reactions are presented for inclusion in the modeling of the ionosphere of Saturn's satellite Titan. Sixteen reactions were re-examined to reduce uncertainties in the previous literature results. In this study we have examined the reactions of N + and N 2 + with CH 4, C 2H 2, C 2H 4, C 2H 6, HCN, CH 2CHCN and HC 3N; the reaction of N + with CH 3CN; the reactions of C 3H 5 + with CH 4, C 2H 2, C 2H 4, C 2H 6, H 2, HCN, HC 3N and CH 2CHCN; the reactions of C 2N 2 + with C 2H 2; C 2H 2 + and C 2N 2; C 2H 4 with C 2H 3 +, C 2H 4 , CHCCNH +, and HC 5N +; HCNH + with C 2H 6; C 3H 6 + with C 3H 6; HCN with C 2 H 6 +, C 3H 6 + , cC 3H 6 + ,C 2N 2 + and NO +; N 2 with C 2H 2 + and C 2H 5 +; C 2H 4 + and HC 3N. The ions selected for this study were derived either from nitrogen, appropriate hydrocarbons or nitrites. The reactant neutrals were selected on the basis of their known presence in Titan's atmosphere. The reaction products are consistent with the expected increase in ion size through ion molecule reaction processing. Data are also presented for the reactions of 23 ions with molecular nitrogen. Almost all of these ions are unreactive with N 2.