1. Influence of the F–H⋯N hydrogen bond on the C–H isolated stretching in aromatic azines
- Author
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Rusu, Victor H., da Silva, João Bosco P., and Ramos, Mozart N.
- Subjects
- *
HYDROFLUORIC acid , *NONMETALS , *HYDROGEN bonding , *SPECTRUM analysis - Abstract
Abstract: MP2/6-31++G(d,p) ab initio molecular orbital calculations have been employed to investigate the effect of the F–H⋯N hydrogen bond between aromatic azines and hydrogen fluoride on the degree of aromaticity of these azines in considering the CH stretching region of its IR spectrum. Our results have revealed a lowering of the aromatic character of the azine ring. This corresponds to larger vibrational frequencies and smaller CH stretching intensities after complexation. An analysis based on a charge–charge flux-overlap model for infrared intensities indicates that this decrease on the intensity values is mainly due to the CH charge flux term. It becomes less negative upon the H-bond formation, whereas the hydrogen charge is only slightly increased. [Copyright &y& Elsevier]
- Published
- 2008
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