Intra-Cavity Inclusion of [CpFe~(II)(arene)] + Guests by Cyclotriveratrylene

摘要

The trimeric, saucer-shaped molecule Cyclotriveratrylene (CTV, 1) forms the skeleton of the cryptophanes, a family of molecules that displays an impressive range of host-guest complexation behavior involving inclusion of neutral and cationic guest molecules within their elliptical cavities. CTV itself has also been known for many years to form inclusion complexes incorporating a range of neutral guest molecules. These solvates are almost invariably of the channel variety, however, in which the CTV units pack in a columnar fashion in the solid state along the crystallographic b axis, while guest species reside only in lattice voids caused by the inefficient packing of. these columns. Two distinct classes of CTV inclusion compounds have been identified based upon variations in the length of the crystallographic b axis and in the solid-state infrared spectra of the compounds. We have recently rationalized their differences on the basis of the hydrogen-bond-accepting properties of included guest species. As a consequence of the columnar packing mode, conventional inclusion complexes of CTV are generally not as interesting as those of some derivatives (for example, CTC = cyclotricatechylene), since they do not exploit the molecular cavity of this host.