Cyclopentadienyl type η5-π-complexes of C60 fullerene derivatives with indium and thallium: simulation of molecular and electronic structure by the MNDO/PM3 methodof C60 fullerene derivatives with indium and thallium: simulation of molecular and electronic structure by the MNDO/PM3 method

The results of MNDO/PM3 calculations of η⁵-π-C₆₀R₅M complexes (R=H and Ph; M=Tl and In) are reported. Local energy minima and geometric parameters as well as the heats of formation and ionization potentials were determined for all systems in question. The nature of chemical M—pent bonding (pent is the pentagonal face) is discussed. The results of calculations are compared with experimental data that confirm our predictions about the possibility of existence of stable cyclopentadienyl type η⁵-π-complexes of C₆₀ fullerence derivatives. The stability of the C₆₀In₁₂ complex with theI _h symmetry, in which the In atoms are coordinated to each of 12 pentagonal faces of C₆₀ fullerene, was estimated. The energy of the In—pent bond (62.4 kcal mol⁻¹) is close to that in C₆₀H₅In (64.5 kcal mol⁻¹). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1935–1940, November, 1997.