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Solvent–guest control of two extremely similar tetrahydrofuran inclusion structures
Author(s) -
Gao Jiabin,
Bhadbhade Mohan M.,
Bishop Roger
Publication year - 2014
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520613031727
Subject(s) - tetrahydrofuran , inclusion (mineral) , solvent , control (management) , chemistry , organic chemistry , computer science , artificial intelligence , mineralogy
Racemic 2,4,6,8‐tetracarbomethoxybicyclo[3.3.0]octa‐2,6‐diene‐3,7‐diol, C 16 H 18 O 10 (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.