Three- and four-membered ring compounds with functional groups and bulky substituents have proved to be a rewarding new source of inclusion hosts. These hosts form clathrates with a variety of uncharged organic molecules ranging from protic dipolar to apolar compounds (168 different inclusion species). Formation and selectivity depend in a systematic manner on structural parameters of the host, such as the nature, number, and position of functional groups, the substituents, and ring size. X-ray structure analyses of two inclusion compounds [1-t-BuOH (1:1): P212121; = 9.782 (1), b = 11.376 (1), c = 17.603 (1) Å;Z = 4. 17·MeCN (1:1): Pbcn; a = 12.314(1), b= 16.074 (1), c= 12.938 (1) Å; Z = 4] and of a free host molecule [1: P21; a = 7.339 (2), b = 11.657 (4), c = 9.149 (3) Å; β = 110.07°; Z = 2] are reported, revealing the building principles of the new clathrate family. The structures exhibit linear chains of inter-/intramolecular H bridges between carboxylic groups in the free host 1 and H-bridge aggregation of host and guest molecules in infinite helical chains for the 1·t-BuOH (1:1) inclusion. In 17·MeCN (1:1), the guest molecules are tightly enclosed by the host framework without further specific interactions.
ASJC Scopus subject areas
- Colloid and Surface Chemistry