Variable-Temperature Ion Mobility Time-of-Flight Mass Spectrometry Studies of Electronic Isomers of Kr2+ and CH3OH+• Radical Cations

Abstract

Preliminary results from a liquid nitrogen-cooled ion mobility (IM) orthogonal-time-of-flight (o-ToF) mass spectrometer applied to the separation of electronic isomers of Kr2+ and methanol radical cations (conventional and distonic) are presented. Ab initio calculations were used to estimate the energies and energy barriers to interconversion between conventional (CH3OH•+) and distonic (CH2•OH2+) radical cations. In addition, computations and experiments are used to compare ion-neutral collision cross-sections for CH3OH•+ and CH2•OH2+ radical cations and suggest that the mobility separation is achieved by ion-neutral interactions between ions and neutral buffer gas.