Conformational equilibria in o-anisic acid and its monohydrated complex: the prevalence of the trans-COOH form
The conformation of ortho-anisic acid and its monohydrated clusters generated in a supersonic jet has been studied by rotational spectroscopy to analyze the structural implications of ortho substitution. The dominant monomer species shows a trans-COOH arrangement stabilized by an intramolecular O–H....
| Autores: | , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión borrador |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universidad de Valladolid |
| Repositorio: | UVaDOC. Repositorio Documental de la Universidad de Valladolid |
| OAI Identifier: | oai:uvadoc.uva.es:10324/46359 |
| Acceso en línea: | https://doi.org/10.1039/c9cp00552h http://uvadoc.uva.es/handle/10324/46359 |
| Access Level: | acceso abierto |
| Palabra clave: | Espectroscopía de rotación Quimica Quimica Fisica Acido orto-anisico Water cluster rotational spectroscopy structure microsolvation hydrogen bond conformationla equilibria 23 Química 2301.13 Espectroscopia de Microondas 2307 Química Física |
| Sumario: | The conformation of ortho-anisic acid and its monohydrated clusters generated in a supersonic jet has been studied by rotational spectroscopy to analyze the structural implications of ortho substitution. The dominant monomer species shows a trans-COOH arrangement stabilized by an intramolecular O–H...O hydrogen bond from the acid to the methoxy group. The spectra of two non-planar skeleton monomer forms with a cis-COOH arrangement have also been detected. A tunneling doublet has been observed for the most stable cis-COOH conformer. The periodic potential energy function for the COOH internal rotation connecting these cis forms has been estimated from the experimental data. For the first time a water complex with an acid in a trans-COOH configuration has been observed. This is more abundant than the other weak form observed for the complex, characterized by a cis-COOH arrangement. The observation of the rotational spectra of salicylic acid, methyl salicylate and methyl 2-methoxybenzoate, formed upon heating of ortho-anisic acid, gives additional interest in the chemistry of ortho substituted benzoic acids. |
|---|