Crystallographic observation of 'induced fit' in a cryptophane host-guest model system.
Nat Commun 2010;
1:148. [PMID:
21266998 PMCID:
PMC3105606 DOI:
10.1038/ncomms1151]
[Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 11/30/2010] [Indexed: 12/19/2022] Open
Abstract
Cryptophane-A, comprised of two cyclotriguaiacylenes joined by three ethylene linkers, is a prototypal organic host molecule that binds reversibly to neutral small molecules via London forces. Of note are trifunctionalized, water-soluble cryptophane-A derivatives, which exhibit exceptional affinity for xenon in aqueous solution. In this paper, we report high-resolution X-ray structures of cryptophane-A and trifunctionalized derivatives in crown–crown and crown–saddle conformations, as well as in complexes with water, methanol, xenon or chloroform. Cryptophane internal volume varied by more than 20% across this series, which exemplifies 'induced fit' in a model host–guest system.
Cryptophane-A is a prototypical organic host molecule that binds reversibly to neutral guest molecules. Taratula et al. report X-ray structures of cryptophane-A complexed with a range of host molecules to show that the cryptophane host–guest system exhibits ‘induced fit’.
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