Competition between hydrogen bonds and van der Waals forces in intermolecular structure formation of protonated branched-chain alcohol clusters

Sugawara, N; Hsu, PJ; Fujii, A; Kuo, JL

HERO ID

5348663

Reference Type

Journal Article

Year

2018

Language

English

PMID

30276413

HERO ID 5348663
In Press No
Year 2018
Title Competition between hydrogen bonds and van der Waals forces in intermolecular structure formation of protonated branched-chain alcohol clusters
Authors Sugawara, N; Hsu, PJ; Fujii, A; Kuo, JL
Journal Physical Chemistry Chemical Physics
Volume 20
Issue 39
Page Numbers 25482-25494
Abstract To investigate the influence of bulky alkyl groups on hydrogen-bonded (H-bonded) network structures of alcohols, infrared (IR) spectra of protonated clusters of 2-propanol (2-PrOH) and tert-butyl alcohol (t-BuOH) were observed in the OH and CH stretch regions. In addition, by varying the tag species, the temperature dependence profile of the isomer population of H+(t-BuOH)n was revealed. An extensive search for stable isomers was performed using dispersion-corrected density functional theory methods, and temperature-dependent IR spectral simulations were done on the basis of the harmonic superposition approximation. The computational results qualitatively agreed with the observed size and temperature dependence of the H-bonded network structures of these protonated bulky alcohol clusters. However, the difficulty in the quantitative evaluation of dispersion was also demonstrated. It was shown that H+(2-PrOH)n (n = 4-7) have essentially the same network structures as the protonated normal alcohol clusters studied so far. On the other hand, H+(t-BuOH)n (n = 4-8) showed a clear preference for the smaller-membered ring structures, that is very different from the preference of the protonated normal alcohol clusters. The origin of the different structure preferences was discussed in terms of the steric effect and dispersion.
Doi 10.1039/c8cp05222k
Pmid 30276413
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English