Crystal structures and phase relationships of 2 polymorphs of 1,4-Diazabicyclo[3.2.2]nonane-4-Carboxylic Acid 4-Bromophenyl Ester Fumarate, A selective a-7 nicotinic receptor partial agonist
Two polymorphs of the 1:1 fumarate salt of 1,4-diazabicyclo[3.2.2]nonane-4-carboxylic acid 4-bromophenyl ester, developed for the treatment of cognitive symptoms of schizophrenia and Alzheimer disease, have been characterized. The 2 crystal structures have been solved, and their phase relationships...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| 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:2117/103613 |
| Acceso en línea: | https://hdl.handle.net/2117/103613 https://dx.doi.org/10.1016/j.xphs.2015.10.015 |
| Access Level: | acceso abierto |
| Palabra clave: | Crystals Thermodynamics polymorphism thermodynamics physical stability solid state phase transition topological phase diagram Clapeyron equation crystal structure high pressure thermal analysis Termodinàmica Cristalls Àrees temàtiques de la UPC::Física::Física de l'estat sòlid |
| Sumario: | Two polymorphs of the 1:1 fumarate salt of 1,4-diazabicyclo[3.2.2]nonane-4-carboxylic acid 4-bromophenyl ester, developed for the treatment of cognitive symptoms of schizophrenia and Alzheimer disease, have been characterized. The 2 crystal structures have been solved, and their phase relationships have been established. The space group of form I is P21/c with a unit-cell volume of 1811.6 (5) Å3 with Z = 4. The crystals of form I were 2-component nonmerohedral twins. The space group of form II is P21/n with a unit-cell volume of 1818.6 (3) Å3 with Z = 4. Relative stabilities have been inferred from experimental and topological P-T diagrams exhibiting an overall enantiotropic relationship between forms I and II although the solid–solid transition has never been observed. The slope of the I-II equilibrium in the P-T diagram is negative, form II is the stable phase below the solid–solid transition temperature of 371 K, and form I exhibits a stable melting equilibrium. The I-II transition temperature has been obtained from the intersection of the sublimation curves of the 2 solid forms. |
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