Encapsulation of Formaldehyde and Hydrogen Cyanide in an Open-Cage Fullerene

摘要

Reaction of C63NO2(Ph)(2)(Py) (1) with o-phenylenediamine and pyridine produces a mixture of C63H4NO2(Ph)(2)(Py)(N2C6H4) (2) and H2O@2. Compound 2 is a new open-cage fullerene containing a 20-membered heterocyclic orifice, which has been fully characterized by NMR spectroscopy, high-resolution mass spectrometry, and X-ray crystallography. The elliptical orifice of 2 spans 7.45 angstrom along the major axis and 5.62 angstrom along the minor axis, which is large enough to trap water and small organic molecules. Thus, heating a mixture of 2 and H2O@2 with hydrogen cyanide and formaldehyde in chlorobenzene affords HCN@2 and H2CO@2, respectively. The H-1 NMR spectroscopy reveals substantial upfield shifts for the endohedral species (delta = -1.30 to -11.30 ppm), owing to the strong shielding effect of the fullerene cage.