Effect of Nonproximate Atomic Substitution on Excited State Intramolecular Proton Transfer
Document Type
Article
Journal/Book Title
Journal of Computational Chemistry
Publication Date
12-1998
Publisher
Wiley-Blackwell
Volume
19
Issue
2
First Page
129
Last Page
138
Abstract
The central C atom of the OCCCO skeleton of the malonaldehyde molecule is replaced by N, and the effects upon the intramolecular H-bond and the proton transfer are monitored by ab initio calculations in the ground and excited electronic states. The H-bond is weakened in the singlet and triplet states arising from n→π* excitation in both molecules, which is accompanied by a heightened barrier to proton transfer.3ππ* behaves in the same manner, but the singlet ππ* state has a stronger H-bond and lower barrier. Replacement of the central C atom by N strengthens the intramolecular H-bond. Although the proton transfer barrier in the ground state of formimidol is lower than in malonaldehyde, the barriers in all four excited states are higher in the N-analog. The latter substitution also dampens the effect of the n→π* excitation upon the H-bond and increases the excitation energies of the various states, particularly ππ*. © 1998 John Wiley & Sons, Inc. J Comput Chem 19: 129–138, 1998
Recommended Citation
Effect of Nonproximate Atomic Substitution on Excited State Intramolecular Proton Transfer M. Cuma, C. Thompson, S. Scheiner J. Comput. Chem. 1998 19 129-138.
Comments
http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291096-987X%2819980130%2919:2%3C129::AID-JCC5%3E3.0.CO;2-W/abstract
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Published by Wiley-Blackwell in Journal of Computational Chemistry.