Reactions and thermochemistry of protonated methanol clusters produced by electron impact ionization
- Virginia Commonwealth Univ., Richmond, VA (United States)
- National Inst. of Standards and Technology, Gaithersburg, MD (United States)
Protonated methanol clusters H{sup +} (CH{sub 3}OH){sub n} for n in the range 1-17 have been formed by electron impact ionization of neutural methanol clusters. The formation of H{sup +}(H{sub 2}O)(CH{sub 3}OH){sub n} clusters is observed to occur only for n {ge} 6. In CD{sub 3}OH clusters, both H{sup +}(CD{sub 3}OH){sub n} and D{sup +}(CD{sub 3}OH){sub n} were formed. The D{sup +}/H{sup +} ratio showed a strong dependence on cluster size, which is apparently related to neutral boiloff sequences. Reduced data for production of H{sup +}(H{sub 2}O)(CH{sub 3}OH){sub n} reveals two distinct size-specific manifolds. The results also suggest that the ion H{sup +}(CH{sub 3}OH){sub 3} is particularly stable and corresponds to the filling of the first solvent shell around a protonated methanol molecule. New thermochemical data are presented for the H{sup +}(CH{sub 3}OH){sub n} series. These data show that the limiting attachment energy of CH{sub 3}OH molecules to the large clusters (9 kcal/mol) is similar to the condensation energy of liquid methanol, and therefore the complex intermolecular forces in the liquid are also present in the clusters. 39 refs., 10 figs., 2 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 255250
- Journal Information:
- Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 5 Vol. 96; ISSN JPCHAX; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
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