The Proton Position in Amine-HX (X=Br, I) Complexes

Authors

Z. Latajka
Steve Scheiner, Utah State UniversityFollow
H. Ratajczak

Document Type

Article

Journal/Book Title

Chemical Physics

Publication Date

10-1992

Publisher

Elsevier

Volume

166

Issue

1-2

First Page

85

Last Page

96

Abstract

Proton transfer potential energy surfaces are computed by ab initio methods for complexes of HBr and HI with NH₃ and mono, di, and trimethylamine. The fundamental natures of the SCF and MPn surfaces are distinct in that two separate minima are present in the SCF surfaces, corresponding to a neutral and ion pair, whereas only one minimum is encountered in most of the correlated surfaces. The single minimum in the MP2 surfaces of most of the complexes represents an ion pair. The first exception is BrH⋯NH₃ which exists as a neutral pair. The bridging proton in BrH⋯NH₂CH₃ is located approximately midway between the two molecules in a “shared” arrangement. The last exception is IH⋯NH₃, the surface of which may be best characterized as a long shallow valley for proton motion. The binding energies of these complexes rise as the amine becomes more basic due to progressive methylation.

Comments

http://www.sciencedirect.com/science/article/pii/030101049287008W

Publisher PDF is available for download through the link above.

Published by Chemical Physics in Elsevier.

Recommended Citation

The Proton Position in Amine-HX (X=Br, I) Complexes Z. Latajka, S. Scheiner, H. Ratajczak Chem. Phys. 1992 166, 85-96.