title: Dissociative electron-ion recombination of the interstellar species protonated glycolaldehyde, acetic acid, and methyl formate.
abstract: Recently, methyl formate, glycolaldehyde, and acetic acid have been detected in the Interstellar Medium, ISM. The rate constants, α(e), for dissociative electron-ion recombination of protonated gycolaldehyde, (HOCH(2)CHO)H(+), and protonated methyl formate, (HCOOCH(3))H(+), have been determined at 300 K in a variable temperature flowing afterglow using a Langmuir probe to obtain the electron density. The recombination rate constants at 300 K are 3.2 × 10(-7) cm(3) s(-1) for protonated methyl formate and 7.5 × 10(-7) cm(3) s(-1) for protonated glycolaldehyde. The recombination rate constant of protonated acetic acid could not be directly measured, but it appears to have a rate constant, α(e), on the 10(-7) cm(3) s(-1) scale. Several high- and low-temperature measurements for protonated methyl formate were made. In addition, an α(e) measurement at 220 K for protonated glycolaldehyde was performed. The astrochemical implications of the rates of recombination, α(e), and protonation routes are discussed.
authors.affiliation: Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Lawson
authors.forename: David S
authors.initials: DS
authors.lastname: Osborne
authors.forename: Nigel G
authors.initials: NG
authors.lastname: Adams