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

The problem of existence of η⁴-π-complexes of transition metal atoms with Ñ₆₀ fullerene and its simplest bowl-shaped hydrocarbon precursor, corannulene (Ñ₂₀H₁₀), is discussed in the framework of the HF/3-21G and DFT/TZ2P methods. The molecular structures of corannulene and Ñ₆₀ 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. [ABSTRACT FROM AUTHOR]