Fragmentation processes of 1,2‐diphenoxyethane and 2‐phenoxyethanol by electron impact

Abstract

AbstractThe unimolecular fragmentation processes of 1,2‐diphenoxyethane (1) and 2‐phenoxyethanol (2) upon electron impact were investigated by a combination of mass‐analyzed ion kinetic energy (MIKE) spectrometry, deuterium‐labelling, high resolution mass spectrometry, and kinetic energy release (KER) measurement. The MIKE spectrum and the KER measurement indicate that the predominant fragment ion at m/z 120 was generated from metastable 1+· ions via loss of a phenol molecule (C6H6O, 7), and that it has the same structure as the molecular ion of 2,3‐dihydrobenzofuran (C8H8O, 3). The metastable 2+· ion eliminates C2H4O and C2H3O to produce product ions at m/z 94 (C6H6O+·, 7+·) and 95 (C6H7O+) with single and double hydrogen atom transfer, respectively. These reactions occur through some complex rearrangement reactions.