alpha,omega-Alkanediyldiammonium dications sealed within calix[5]arene capsules with a hydrophobic bayonet-mount fastening

作者：Brancatelli Giovanna; Gattuso Giuseppe; Geremia Silvano; Manganaro Nadia; Notti Anna; Pappalardo Sebastiano; Parisi Melchiorre F; Pisagatti Ilenia

来源：CrystEngComm, 2015, 17(41): 7915-7921.

DOI：10.1039/c5ce01558h

A combined XRD and H-1 NMR study revealed that two molecules of tetrakis-(tert-butyloxycarbonylmethoxy)-calix[5]arene carboxylic acid are able to efficiently encapsulate alpha,omega-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.

• 出版日期2015