SCHEDULED MAINTENANCE
α,ω-Alkanediyldiammonium dications sealed within calix[5]arene capsules with a hydrophobic bayonet-mount fastening†
Abstract
A combined XRD and 1H NMR study revealed that two molecules of tetrakis-(tert-butyloxycarbonylmethoxy)-calix[5]arene carboxylic acid are able to efficiently encapsulate α,ω-diaminoalkanes of suitable length as a result of proton-transfer-mediated recognition. In the case of 1,10-diaminodecane and 1,11-diaminoundecane, rim-to-rim attractive van der Waals interactions drive the formation of capsular complexes with a packing coefficient close to 70%. The two calixarene bowls in these capsules are seen in an eclipsed conformation. On the other hand, when the longer 1,12-diaminododecane guest is used, a quasi-capsular complex is formed in which the capsule seal is lost and the two calixarenes are arranged in a staggered conformation as a result of a reciprocal rotation of the two facing macrocyclic cavities. A comparison with similar capsular complexes confirms that a hydrophobic ‘bayonet-mount’ fastening is mandatory for the encapsulation of suitably sized guests.
![Graphical abstract: α,ω-Alkanediyldiammonium dications sealed within calix[5]arene capsules with a hydrophobic bayonet-mount fastening](/en/Image/Get?imageInfo.ImageType=GA&imageInfo.ImageIdentifier.ManuscriptID=C5CE01558H&imageInfo.ImageIdentifier.Year=2015)
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