On the possibility of existence of η4-π-complexes of corannulene (C20H10) and Ñ60 fullerene derivatives

Abstract

The problem of existence of η4-π-complexes of transition metal atoms with N60 fullerene and its simplest bowl-shaped hydrocarbon precursor, corannulene (N20H10), is discussed in the framework of the HF/3-21G and DFT/TZ2P methods. The molecular structures of corannulene and N60 fullerene derivatives, namely, C20H14, C20H16, C60H4, and C60H6 were simulated. These molecules can form stable η4-π-complexes C20H14Fe(CO)3, C20H16Fe(CO)3, C60H4Fe(CO)3, and C60H6Fe(CO)3 in which the Fe atom interacts with C atoms of a fulvene-like or butadiene-like conjugated fragment of the hydrocarbon ligands. The energies of the η4-π-bonds in the complexes under study were compared with the corresponding bond energies in the classical complexes C4H6Fe(CO)3 and C5H6Fe(CO)3. The geometric parameters of C4H6Fe(CO)3 and C5H6Fe(CO)3 obtained from DFT calculations are close to the experimental values. Stabilities of the η4-π-complexes studied and their η5-π-analogs were compared.