Entropy changes in the dissociation of proton-bound complexes: A variational RRKM study

被引：7

作者：

Grabowy, JAD ^{[1
]}

Mayer, PM ^{[1
]}

机构：

[1] Univ Ottawa, Dept Chem, Ottawa, ON, Canada

来源：

JOURNAL OF PHYSICAL CHEMISTRY A | 2004年 / 108卷 / 45期

关键词：

D O I：

10.1021/jp0483829

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Microcanonical variational transition state theory was employed to determine the entropy of activation, DeltaS(double dagger), for the dissociation of a series of acetonitrile-alcohol proton-bound pairs over an internal energy range corresponding to metastable ion decomposition observations on a magnetic sector mass spectrometer. It was found that DeltaS(double dagger) decreases with increasing size of the alcohol chain in the complex. These values ranged from 64 to 75 J K-1 mol(-1) for (CH3CN)(CH3OH)H+, 34-43 J K-1 mol(-1) for (CH3CN)(CH3CH2OH)H+, 6 J K-1 mol(-1) for (CH3CN)(CH3CH2CH2OH)H+, and 11-13 J K-1 mol(-1) for (CH3CN)((CH3)(2)CHOH)H+. The entropy of activation was compared to the thermodynamic AS for the overall reaction, and larger relative changes are observed between AS' values than for AS.

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页码：9726 / 9732

页数：7

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