Polymorphism of 1,3-X-adamantanes (X = Br, OH, CH3) and the crystal plastic phase formation ability
The polymorphism of 1,3-dimethyladamantane (13DMA), 1,3-adamantanediol (13DOHA) and 1,3-dibromoadamantane (13DBrA) has been studied by X-ray powder diffraction, density measurements and differential scanning calorimetry at normal and high-pressure. 13DMA exhibits a low-temperature ordered monoclinic...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/340831 |
| Acceso en línea: | https://hdl.handle.net/2117/340831 https://dx.doi.org/10.1039/c9ce01910c |
| Access Level: | acceso abierto |
| Palabra clave: | Crystals Cristalls Àrees temàtiques de la UPC::Física::Física de l'estat sòlid::Cristalls |
| Sumario: | The polymorphism of 1,3-dimethyladamantane (13DMA), 1,3-adamantanediol (13DOHA) and 1,3-dibromoadamantane (13DBrA) has been studied by X-ray powder diffraction, density measurements and differential scanning calorimetry at normal and high-pressure. 13DMA exhibits a low-temperature ordered monoclinic phase (space group P21/c, Z = 4, Z' = 1) which transforms at 222.6 ± 0.5 K into a high-temperature hexagonal plastic phase (P63/mmc, Z = 26), stable up to the melting point at 246.8 ± 0.5 K at normal pressure. 13DOHA exhibits a low-temperature hexagonal phase (P63/mcm, Z = 6, Z' = 0.25) which transforms into a face-centered cubic plastic phase (Fm[3 with combining macron]m). 13DBrA exhibits a unique ordered orthorhombic phase (Pnma, Z = 4, Z' = 0.5) which remains till the melting point at 382.1 ± 0.5 K. The stability temperature domain of the plastic phases increases with pressure for both 13DMA and 13DOHA. The ability to form the plastic phase for these compounds as well as a series of adamantanes derivatives is analysed through the globularity and asphericity parameters derived from the Hirshfeld surface analysis. |
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