Sandwich complexes of Si, Ge, Sn, and Pb with cyclopentadienyl type derivatives of corannulene and fullerene C60: stability estimates and molecular and electronic structure prediction by the MNDO/PM3 method

Abstract

The ability of cyclopentadienyl type derivatives of corannulene C20H10 and fullereneIh-C60 to form η5-π-complexes and the problem of their existence is discussed. MNDO/PM3 calculations of half-sandwich complexes η5-π-MC20H15, η5-π-MC20H15+, η5-π-MC60H5, η5-π-MC60H5 and sandwich complexes 2η5-π-M(C20H15)2, 2η5-π-M(C20H15)2, 2η5-π-M(C60H5)2 (M=Si, Ge, Sn, Pb) were performed. For all systems studied, local minima were found on corresponding potential energy surfaces and the heats of formation, geometric parameters, and distributions of effective atomic charges were calculated. Sandwich complexes are most likely to exist with M=Si and Ge. The energy and geometric characteristics of η5-π-complexes of corannulene were compared with those of η5-π-complexes of fullereneIh-C60. It was concluded that the results of quantum-chemical calculations of sandwich type corannulene derivatives can be used for simulation of the geometry and electronic structure of analogous complexes of fullereneIh-C60.