CYCLOPENTADIENYL TYPE ETA(5)-PI-COMPLEXES OF C-60 FULLERENE DERIVATIVES WITH INDIUM AND THALLIUM - SIMULATION OF MOLECULAR AND ELECTRONIC-STRUCTURE BY THE MNDO PM3 METHOD/

The results of MNDO/PM3 calculations of eta(5)-pi-C60R5M complexes (R = H and Ph; M = TI and In) are reported. Local energy minima and geome tric parameters as well as the heats of formation and ionization poten tials were determined for all systems in question. The nature of chemi cal M-pent bonding (pent is the pentagonal face) is discussed. The res ults of calculations are compared with experimental data that confirm our predictions about the possibility of existence of stable cyclopent adienyl type eta(5)-pi-complexes of C-60 fullerene derivatives. The st ability of the C60In12 complex with the I-h symmetry, in which the In atoms are coordinated to each of 12 pentagonal faces of C-60 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)).