Oswald, I D H and Allan, D R and Motherwell, W D S and Parsons, S (2005) Structures of the monofluoro- and monochlorophenols at low temperature and high pressure. Acta Crystallographica Section B: Structural Science, 61 (Part 1). pp. 69-79. ISSN 0108-7681Full text not available in this repository. (Request a copy from the Strathclyde author)
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 2(1) 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 2(1) axis, although there are significant distortions from this ideal geometry. The two phases of 4-chlorophenol consist of chains or rings connected by C - Cl ... H interactions. The low-temperature 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 low-temperature form.
|Keywords:||X-ray diffraction, crystal structures, database, phenols, polymorphism, hydrogen bonding, high pressure, low temperature, Pharmacy and materia medica, Biochemistry, Genetics and Molecular Biology(all)|
|Subjects:||Medicine > Pharmacy and materia medica|
|Department:||Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences|
|Depositing user:||Pure Administrator|
|Date Deposited:||01 Jul 2011 15:00|
|Last modified:||27 Apr 2016 16:49|