The quest for a molecular capsule assembled via halogen bonds
CrystEngComm, 2012,14, 6366-6368
C. B. Aakeröy, A. Rajbanshi, P. Metrangolo, G. Resnati, M. F. Parisi, J. Desper, T. Pilati
Fig. 2 Space filling representation of the closed dimeric capsule 2(E)·B(A) (see ESI? for numbering scheme) held together by four IN XBs between one cavitand 2 and one calix B. Colour code: Grey, carbon; white, hydrogen; red, oxygen; blue, nitrogen; yellow, fluorine; violet, iodine.
Fig. 2 Space filling representation of the closed dimeric capsule 2(E)·B(A) (see ESI? for numbering scheme) held together by four IN XBs between one cavitand 2 and one calix B. Colour code: Grey, carbon; white, hydrogen; red, oxygen; blue, nitrogen; yellow, fluorine; violet, iodine.
ABSTRACT
A halogen-bonded capsule is obtained via directed assembly of a rigid tetra(3-pyridyl) cavitand and a flexible tetra(4-iodotetrafluorophenyl)calix[4] arene. The pyridyl nitrogen atoms from one cavitand molecule interact with the iodine atoms of a single calixarene molecule through short and directional I⋯N halogen bonds. The flexibility of the ethylenedioxy moieties on the calixarene platform results in positional flexibility of the iodotetrafluorobenzene sites which, coupled with a supramolecular chelating effect, allow for an effective partner-induced geometric fitting between four nitrogen atoms on the cavitand and four iodine atoms on the calixarene.