Theoretical study of host-guest interaction in model endohedral fullerenes with CH4 and He4 into the C60H36, C60H24, C84, and C60 cages Article

Charkin, OP, Klimenko, NM, Charkin, DO et al. (2004). Theoretical study of host-guest interaction in model endohedral fullerenes with CH4 and He4 into the C60H36, C60H24, C84, and C60 cages . 49(5), 723-733.



cited authors

  • Charkin, OP; Klimenko, NM; Charkin, DO; Mebel, AM

fiu authors

abstract

  • The equilibrium geometrical parameters, dissociation energies, vibrational frequencies, and magnetic shielding constants of a series of model endohedral fullerene complexes with the CH4 molecule or four He atoms inside the C60H36 (T), C60H24 (T), C 84 (Td), and C60 cages were calculated at the 6-31G and 6-31G* DFT B3LYP levels. The effect of the size and shape of the encapsulated particle and the cavity on the host-guest interaction and its manifestations in the properties of endofullerenes were studied. The calculations predict that the encapsulation of CH4 or He4 slightly affects the properties of the cages but is accompanied by the contraction of the guest, large hypsochromic shifts of its stretching vibration frequencies (ν(CH) ≈ 50-150 cm-1), and an increase in the magnetic shielding constants of the guest atoms (Δσ(C) ≈ 5 ppm, Δσ(H) ≈ 7 ppm, Δσ(He) ≈ 8 ppm). The shifts Δν and Δσ decrease with an increase in the size of a cage as the match between the cage and guest shapes becomes better; however, these shifts remain considerable even in the "spacious" cluster CH 4@C84 and can easily be monitored by IR and Raman spectroscopy and NMR. Copyright © 2004 by MAIK "Nauka/ Interperiodica" (Russia).

publication date

  • January 1, 2004

start page

  • 723

end page

  • 733

volume

  • 49

issue

  • 5