Reactions of translationally cold trapped CCl+ with acetylene (C2H2).

Ion-neutral chemical reactions are important in several areas of chemistry, including in some regions of the interstellar medium, planetary atmospheres, and comets. Reactions of CCl+ with C2H2 are measured, and the main products include C3H2 + and C3H+, both relevant in extraterrestrial environments. Accurate branching ratios are obtained, which favor the formation of C3H2 + over C3H+ by a factor of four. The measured rate constants are on the order of Langevin, and complementary electronic structure calculations are used to aid in the interpretation of experimental results.