Fullerene C60 as a ?5- and ?6-ligand in sandwich-type ?-complexes with transition metals

Coordination chemistry on carbon surfaces

“…Early theoretical calculations have shown that metal coordination to fullerenes in a 6 fashion is much less stable than other hapticities [448][449][450]. The binding energies and stability of 6 -M C 60 complexes have been predicted to be less strong and weaker than the respective benzene complexes [444,445]. Nevertheless, C 60 Cr C 60 has a moderately stable species [491].…”

“…This methodology allows one to obtain a plethora of metal transition compounds, including the formation of dinuclear metal complexes since there are two cyclopentadiene (Cp) parts on the top and bottom of the C 60 [443]. Similarly, 3 , 4 and 6 coordination modes have been predicted to be possible only if the structure of the fullerene is modified [444][445][446][447].…”

“…The formation of stable 5 complexes of fullerene is highly improbable due the delocalization of the -electron density. The metal-C 60 interaction in Cp M C 60 complexes (M = Fe, Ru and Os) is calculated to be weaker than the M Cp bonds in ferrocene, ruthenocene, and osmocene [445]. Subsequently, calculations of complexes C 60 R 5 M (R = H, Ph) predicts that the addition of substituents in the ␣-position of the five membered ring allows the existence of stable 5 complexes [446].…”

Coordination Modes and Different Hapticities for Fullerene Organometallic Complexes

“…However Stankevich and his group [43,57] indicate that a perturbation of the system, consistent with the addition of R groups to the surface of the C 60 in six α positions with respect to a common six-member ring is able to stabilize the coordination of a metal atom in η 6 manner. A similar calculation was performed by Rogers and Marynick [41] considering an C 60 Cr(CO) 3 complex, where they concluded that the binding energy is lower than in the case of an analogous compound containing only a benzene ring instead of the fullerene, but they concluded that the complex should be stable.…”

Corannulene derivatives as models for calculations of fullerene derivatives

“…[3][4][5] Quantum-chemical calculations demonstrated 5 that if rls-~-complexes of futlerene with MCp + moieties (where M is a transition-metal atom) occur, they should be less stable than the analogous classical M(Cp)2 sandwich systems. [3][4][5] Quantum-chemical calculations demonstrated 5 that if rls-~-complexes of futlerene with MCp + moieties (where M is a transition-metal atom) occur, they should be less stable than the analogous classical M(Cp)2 sandwich systems.…”