The vaporization enthalpies of 2- and 4-(N,N-dimethylamino)pyridine, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, imidazo[1,2-a]pyridine and 1,2,4-triazolo[1,5-a]pyrimidine by correlation-gas chromatography
| Autor: | Nigam P. Rath, Vasiliy A. Pozdeev, James S. Chickos, Dmitry Lipkind, Sergey P. Verevkin |
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| Rok vydání: | 2011 |
| Předmět: |
Pyrimidine
chemistry.chemical_element Crystal structure Nitrogen Medicinal chemistry Surfaces Coatings and Films chemistry.chemical_compound 1 8-Diazabicyclo[5.4.0]undec-7-ene chemistry Pyridine Vaporization Materials Chemistry Organic chemistry 1 5-Diazabicyclo[4.3.0]non-5-ene Gas chromatography Physical and Theoretical Chemistry |
| Zdroj: | The journal of physical chemistry. B. 115(27) |
| ISSN: | 1520-5207 |
| Popis: | The vaporization enthalpies of a series of heterocyclic compounds some suspected of showing evidence of a higher degree of self-association in comparison to many other nitrogen heterocycles have been measured both by correlation gas chromatography (CGC) and for comparison by transpiration. The compounds share some structural similarities. They include 2- and 4-(N,N-dimethylamino)pyridine, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,2,4-triazolo[1,5-a]pyrimidine and imidazo[1,2-a]pyridine. The vaporization enthalpies of the first three of the compounds are well reproduced by a standard series of reference compounds, mainly pyridine derivatives. The latter two compounds and 4-(N,N-dimethylamino)pyridine exhibit vaporization enthalpies approximately 7 kJ·mol(-1) larger. Their values are reproduced by using standards previously shown to exhibit stronger but similar self-association properties. The crystal structure of 1,2,4-triazolo[1,5-a]pyrimidine has been determined in an effort to understand the nature of the self-association. The molecule crystallizes in planar stacks slightly offset with a stacking distance of 3.24 Å. |
| Databáze: | OpenAIRE |
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