Theoretical study of host-guest interaction in model endohedral fullerenes with tetrahedral molecules and ions of MH4 hydrides inside the C 60H36, 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 tetrahedral molecules and ions of MH4 hydrides inside the C 60H36, C60H24, C84, and C60 cages . 49(6), 868-880.



cited authors

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

fiu authors

abstract

  • The equilibrium geometrical parameters, dissociation energies, normal vibration frequencies, ionization potentials, electron affinities, and magnetic shielding constants of a series of model endohedral fullerenes with hydride molecules and ions MH4 = BH4-, CH4, NH4+, AlH4-, SiH4, and PH4+ inside the C60H36 (T), C 60H24 (T), C84 (Td), and C 60 cages were calculated by the density functional theory B3LYP method with the 6-31G and 6-31G* basis sets. The effect of the steric and electronic factors (the charge and size of the encapsulated particle and the shape of the cavity, etc.) on the host-guest interaction and its manifestations in the properties of endofullerenes were studied. The encapsulation of neutral MH4 hydrides slightly affects the properties of the cages; however, it is accompanied by the contraction of the guest, large hypsochromic shifts of its stretching vibration frequencies Δν, and a significant increase in the magnetic shielding constants of the guest atoms (Δσ). The encapsulation of MH4± ions leads to redistribution of electron density between the guest and the cage and to considerable shifts of frequencies Δν and constants Δσ of the cage atoms. These shifts increase with an increase in the size and negative charge of the guest and decrease as the cage becomes larger and as the match between the cage and guest shapes becomes better; however, these shifts remain considerable even in the "spacious" clusters MH4@C84 and can easily be monitored by IR and Raman spectroscopy and NMR.

publication date

  • January 1, 2004

start page

  • 868

end page

  • 880

volume

  • 49

issue

  • 6