A selected ion flow tube study of the reactions of a sequence of ions with amines

Abstract

In seeking a viable pathway from interstellar species to more complex organics such as the amino acids glycine and alanine, it is possible that through a joining of amine and carboxyl functional groups, a product of interest may be obtained. As a prelude to such a study, the ion–molecule reactions of the simple ions N +, N 2 +, Ar +, CO 2 +, CO +, and O 2 + as well as the protonated species, HCOOH 2 +, CH 3COOH 2 +, and HC(OH)OCH 3 +, with reactant gases CH 3NH 2 and CH 3CH 2NH 2 have been investigated in a selected ion flow tube (SIFT) at 298 K. The neutral amines fragmented to some degree in all cases when reacted with ion species containing no acidic protons, fragmenting more with increasing recombination energy of the primary ion; whereas, the amines readily accept a proton from the protonated acids and methyl formate ions. The rate coefficients of these reactions have also been determined showing that they are nearly all gas kinetic with the ethylamine reaction rate coefficients tending to be slightly less than their methylamine counterparts.