Some Routes in Forming C[sub 3]H[sub n]+] Ions and Deuterated Variants under Interstellar Conditions

Abstract

Laboratory experiments on hydrogenation and deuteration of C 3 + , C 3 H + and C 3 H 2 + in collisions with H 2 and HD have been performed from room temperature down to 15 K using a 22-pole ion-trap. At room temperature C 3 + reacts slowly with H 2 but the reactivity increases with decreasing temperature.. The new reaction rate coefficients are recommended to be included in astrophysical databases. Nonetheless it is still unclear how to explain the large abundance of C 3 H 2 and larger hydrocarbons and their deuterated variants observed in cold interstellar clouds.