Sy. Lee et al., PROTON-TRANSFER REACTIONS WITHIN IONIZED METHANOL CLUSTERS - MASS-SPECTROMETRIC AND MOLECULAR-ORBITAL STUDIES, Journal of mass spectrometry., 30(7), 1995, pp. 969-976
Proton-transfer reactions that proceed within methanol cluster ions we
re studied using an electron impact time-of-flight mass spectrometer,
When CH3OH seeded in helium is expanded and ionized by electron impact
, the protonated species, (CH3OHH+, are the predominant cluster ions i
n the low-mass region, In CH3OD clusters, both (CH3ODH+ and (CH3ODD+ i
ons are observed, The ion abundance ratios, (CH3ODH+/(CH3ODD+, show a
tendency to decrease as the methanol concentration increases, which is
apparently related to the cluster structure and reaction energetics,
The results suggest that the effective formation of(CH3ODH+ ions at lo
w concentration of CH3OD in the expansion is the result of the relativ
ely facile rotation of methanol molecules within the smaller clusters
that tend to form at low CH3OD concentration, Ab initio molecular orbi
tal calculations were carried out to investigate the rearrangement and
dissociative pathways of ionized methanol dimer, Ion-neutral complexe
s, [CH3OH2+...O(H)CH2] and [CH3OH2+...OCH3], are found to play an impo
rtant role in the low-energy pathways for production of CH3OH2+ + CH2O
H (and OCH3) from ionized methanol dimer.