Open AccessThe low‐temperature and high‐pressure crystal structures of cyclobutanol (C 4 H 7 OH)
Author(s) -
McGregor Pamela A.,
Allan David R.,
Parsons Simon,
Pulham Colin R.
Publication year - 2005
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
eISSN - 1600-5740
pISSN - 0108-7681
DOI - 10.1107/s0108768105019191
Subject(s) - alkyl , crystal structure , crystallography , crystal (programming language) , notation , molecule , space group , materials science , high pressure , diffraction , chemistry , x ray crystallography , physics , thermodynamics , organic chemistry , mathematics , computer science , optics , arithmetic , programming language
The low‐temperature and high‐pressure crystal structures of cyclobutanol (C 4 H 7 OH) have been determined using single‐crystal X‐ray diffraction techniques. At temperatures below 220 K, cyclobutanol crystallizes in the Aba 2 space group ( Z ′ = 2) and its crystal structure is composed of pseudo‐threefold hydrogen‐bonded molecular catemers [assigned as in graph‐set notation], which lie parallel to the crystallographic a axis. At a pressure of 1.3 GPa, the crystal symmetry changes to Pna 2 1 ( Z ′ = 1) and the molecular catemers [expressed as C (2) in graph‐set notation] adopt a pseudo‐twofold arrangement. This structural behaviour is in agreement with our previous observations for phenol and its halogenated derivatives 2‐chlorophenol and 4‐fluorophenol, where pressure was found to favour a molecular packing more closely associated with small alkyl groups rather than that of relatively bulky alkyl groups. In addition, an examination of the molecular coordination environment in the low‐temperature and high‐pressure structures of cyclobutanol reveals that the change in structure on application of pressure appears to be driven by the molecules assuming a packing arrangement which more closely resembles that adopted in hard‐sphere structures.