| Autor: |
Oswald, Iain D.H., Allan, David R., Motherwell, W.D. Samuel, Parsons, Simon |
| Předmět: |
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| Zdroj: |
Acta Crystallographica: Section B (Wiley-Blackwell); Feb2005, Vol. 61 Issue 1, p69-79, 11p, 7 Diagrams, 2 Charts |
| Abstrakt: |
2-Fluorophenol, 3-fluorophenol and 3-chlorophenol were recrystallized from frozen solids at 260, 263 and 283 K. All compounds were also crystallized by the application of high pressure (0.36, 0.12 and 0.10 GPa). While 3-fluorophenol and 3-chlorophenol yielded the same phases under both conditions, different polymorphs were obtained for 2-fluorophenol. 4-Chlorophenol was crystallized both from the melt and from benzene to yield two different ambient-pressure polymorphs; crystallization from the melt at 0.02 GPa yielded the same phase as from benzene at ambient pressure. 3-Fluorophenol is unusual in forming a hydrogen-bonded chain along a 21 screw axis. Such behaviour is usually only observed for small alcohols, but here it appears to be stabilized by intermolecular C-H…F hydrogen-bond formation. 3-Chlorophenol is a more typical large alcohol and emulates a fourfold screw axis with two independent molecules positioned about a 21 axis, although there are significant distortions from this ideal geometry. The two phases of 4-chlorophenol consist of chains or rings connected by C-C1…H interactions. The lowtemperature and high-pressure polymorphs of 2-fluorophenol consist of chains of molecules connected through OH…OH hydrogen bonds; while inter-chain C-H…F interactions are significant at high pressure, there are none in the lowtemperature form. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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