title: Gas-phase reactions and rearrangements of alkyl esters with H3O+, NO+, and O2*+: a selected ion flow tube study.
abstract: Selected ion flow tube mass spectrometry (SIFT-MS) has been employed to study the ion-molecule reactions of 17 alkyl esters reacting with the common SIFT-MS reagent ions, H3O+, H3O+.nH2O (n = 1, 2, 3), NO+, and O2+. The majority of reactions were observed to proceed at or near collision rate, with the exception of H3O+.3H2O, which was found to be slow for 8 of 17 alkyl esters. Unexpected product ions in the form of the parent carboxylic acid cation were observed to arise from the H3O+ and NO+ reactions of some alkyl esters. The observed reactions have been probed by the ab initio CBS-4M and G2(MP2,SVP) methods. The postulated reaction pathway involves a 1,5 H atom migration from a beta-carbon onto the carbonyl oxygen.
authors.affiliation: Syft Technologies Ltd., P.O. Box 28149, Christchurch, New Zealand.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Francis
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Milligan
authors.forename: Murray J
authors.initials: MJ
authors.lastname: McEwan