Title

Relationship between the Angular Characteristics of a H-bond and the Energetics of Proton Transfer Occurring Within

Document Type

Article

Journal/Book Title

Journal of Molecular Structure

Publication Date

9-1988

Publisher

Elsevier

Volume

177

First Page

79

Last Page

91

DOI

10.1016/0022-2860(88)80080-2

Abstract

For a number of different H-bonded complexes, the protontransfer potential is computed by ab initio methods for the optimal geometry as well as for various angular distortions. In all cases, it is found that a rocking of one subunit A so as to turn its dipole moment away from the other subunit B causes the equilibrium position of the proton to shift toward A, even if B has a higher proton affinity than A. This shift may be explained on the basis of a better charge-dipole attraction in the preferred AH··B configuration as compared to A··HB. This principle is straightforward for the N bases where the dipole moment is approximately coincident with the N lone pair. The presence of two O lone pairs, neither of which points along the direction of the molecular dipole moment, adds a second factor which results in a net magnification of the above rule.

Comments

http://www.sciencedirect.com/science/article/pii/0022286088800802

Published by Elsevier in Journal of Molecular Structure. Link to publisher version is available. Subscription is required.

Publisher PDF is available for download through the link above.

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