An Open-Cage Fullerene That Mimics the C60H10(5,5)-Carbon Nanotube Endcap to Host Acetylene and Hydrogen Cyanide Molecules.
Treatment of the open-cage fullerene C63H4NO2(Ph)2(Py)(N2C6H4) (1) with methanol at 150 °C results in an orifice-enlargement reaction to give C69H8NO(CO2Me)(Ph)(Py)(N2C6H4) (2). The overall yield from C60to isolated 2 is 6.1 % (four steps). Compound 2 contains a 24-membered elliptic orifice that spans 8.45 Å along the major axis and 6.37 Å along the minor axis. The skeleton of 2 resembles the hypothetic C60H10(5,5)-carbon nanotube endcap. The cup-shaped structure of 2 is able to include water, hydrogen cyanide, and acetylene, forming H2O@2, HCN@2, and C2H2@2, respectively. The molecular structures of H2O@2 and HCN@2 have been determined by X-ray crystallography. The1H NMR spectra reveal substantial upfield shifts for the endohedral species, such as δ=-10.30 (for H2O), -2.74 and -14.26 (for C2H2), and -1.22 ppm (for HCN), owing to the strong shielding effects of the fullerene cage.
Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan.
Chi-Shian
CS
Chen
Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan. wenyann@mail.nsysu.edu.tw.
Wen-Yann
WY
Yeh
cage compounds; fullerenes; host-guest systems; nanotubes; structure elucidation