High-pressure melting equilibrium of chiral compounds: A practical study on chlorinated mandelic acids under carbon dioxide atmosphere
| Autor: | Sabine Kareth, Edit Székely, Alina Hanu, János Béri, Márton Kőrösi |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Atmospheric pressure Process Chemistry and Technology Analytical chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Mandelic acid 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Differential scanning calorimetry chemistry Carbon dioxide Melting point Chemical Engineering (miscellaneous) Enantiomer 0210 nano-technology Waste Management and Disposal Eutectic system Phase diagram |
| Zdroj: | Journal of CO2 Utilization. 37:173-179 |
| ISSN: | 2212-9820 |
| DOI: | 10.1016/j.jcou.2019.11.026 |
| Popis: | Chiral molecules pose great research potential related to their wide applications in various industries due to the different biological effects of enantiomers. Chiral temperature-composition (melting) phase diagrams are widely available for atmospheric pressure, and those are frequently applied to predict the maximal efficiency of enantioseparation. However, self-disproportionation of enantiomers has already been observed in gas antisolvent fractionation as well. Here, we present the first chiral temperature-composition phase diagrams under carbon dioxide pressure. Chiral temperature-composition phase diagrams of 2-, 3- and 4-chloromandelic acids were determined experimentally. High pressure differential scanning calorimetry and the visual first and last melting point method were used simultaneously to determine the temperature-composition phase diagrams of the compounds. Results were compared to the atmospheric phase diagrams. At 16 and 20 MPa pressures modest melting point depressions of 10−18 °C were observed for any enantiomeric compositions, while the eutectic composition remained practically unaffected. The Schroder–van Laar and Prigogine–Defay equations, widely accepted for the prediction of atmospheric temperature-composition phase diagrams of enantiomeric mixtures, were proved to be applicable also in the presence of a soluble pressurized gas. |
| Databáze: | OpenAIRE |
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