Acta Cryst. (2014). B70, 126-131 [ doi:10.1107/S2052520613031727 ]
Abstract: Racemic 2,4,6,8-tetracarbomethoxybicyclo[3.3.0]octa-2,6-diene-3,7-diol, C16H18O10 (1), was known previously to yield two solvent-free polymorphs and also a clathrate inclusion crystal form. Crystallization of (1) yields two inclusion compounds containing tetrahydrofuran (THF): (1)4·THF is obtained from a mixture of THF and methanol, whereas (1)2·THF is obtained from pure THF. The X-ray crystal structures reveal that the two compounds are extremely similar and that their host arrangements are essentially identical. They differ, however, in the proportion, orientation and host-guest interaction of the included THF molecules. The disordered guest molecules in (1)4·THF are oriented along the guest channel direction, whereas in (1)2·THF they lie across the channel. This unusual solvent-guest control of inclusion structures has implications relating to the formation of polymorphic structures and other competing crystal forms.
CCDC references: 958231 and 958232
Keywords: solvent-guest; inclusion compounds; clathrate crystal; polymorphism.
Portable Document Format (PDF) file (35.3 kbytes)
To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.
The download button will force most browsers to prompt for a file name to store the data on your hard disk.
Where possible, images are represented by thumbnails.