Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

5-2002

Journal or Book Title

Journal of the American Chemical Society

Volume

124

Issue

21

First Page

6162

Last Page

6167

DOI

10.1021/ja020147l

Abstract

Multi-reference as well as single-reference quantum mechanical methods were adopted to study the potential energy surface along three possible surface reaction mechanisms of acrylonitrile on the Si(100)-2×1 surface. All three reactions occur via stepwise radical mechanisms. According to the computed potential energy surfaces, both [4+2] and [2+2]CNcycloaddition products resulting from the reactions of surface dimers with the C⋮N of acrylonitrile are expected, due to the negligible activation barriers at the surface. Another possible surface product, [2+2]CC, requires a 16.7 kcal/mol activation energy barrier. The large barrier makes this route much less favorable kinetically, even though this route produces the thermodynamically most stable products. Isomerization reactions among the surface products are very unlikely due to the predicted large activation barriers preventing thermal redistributions of the surface products. As a result, the distribution of the final surface products is kinetically controlled leading to a reinterpretation of recent experiments. An intermediate Lewis acid−base type complex appears in both the [4+2] and [2+2]CNcycloadditions entrance channels, indicating that the surface may act as an electrophile/Lewis acid toward a strong Lewis base substrate.

Comments

Reprinted (adapted) with permission from Journal of the American Chemical Society 124 (2002): 6162, doi:10.1021/ja020147l. Copyright 2002 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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