Experimental and Theoretical Study of the Structures and Enthalpies of Formation of the Synthetic Reagents 1,3-Thiazolidine-2-thione and 1,3-Oxazolidine-2-thione
| Autor: | María Victoria Roux, Manuel Temprado, Archana R. Parameswar, Concepción Foces-Foces, Alexei V. Demchenko, Pilar Jiménez, Joel F. Liebman, Rafael Notario, Carol A. Deakyne, James S. Chickos, Alicia K. Ludden |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry A. 113:10772-10778 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp9034216 |
| Popis: | This paper reports an experimental and a theoretical study of the structures and standard (p(o) = 0.1 MPa) molar enthalpies of formation of the synthetic reagents 1,3-thiazolidine-2-thione [CAS 96-53-7] and 1,3-oxazolidine-2-thione [CAS 5840-81-3]. The enthalpies of combustion and sublimation were measured by rotary bomb combustion calorimetry, and the Knudsen effusion technique and gas-phase enthalpies of formation values at T = 298.15 K of (97.1 +/- 4.0) and -(74.4 +/- 4.6) kJ.mol(-1) for 1,3-thiazolidine-2-thione and 1,3-oxazolidine-2-thione, respectively, were determined. G3-calculated enthalpies of formation are in reasonable agreement with the experimental values. In the solid state, 1,3-thiazolidine-2-thione exists in two polymorphic forms (monoclinic and triclinic) and 1,3-oxazolidine-2-thione exits in the triclinic form. The isostructural nature of these compounds and comparison of their molecular and crystal structures have been analyzed. The experimental X-ray powder diffractograms have been compared with the calculated patterns from their structures for identification of the polymorphic samples used in this study. A comparison of our results with literature thermochemical and structural data for related compounds is also reported. |
| Databáze: | OpenAIRE |
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