Concave-Bound π-Bowl Gyclopentadienyl Iron Complexes of Sumanene

摘要

Fullerenes and carbon nanotubes are expected to be applied to functional materials depending on their characteristic properties derived from curved π-conjugated systems. In this context, "π-bowls" possessing a partial structure of C_(60), such as corannulene (C_(20)H_(10)) and sumanene (1, C_(21)H_(12)), are considered to be another class of curved π-conjugated materials. In the coordination chemistry of π-bowl compounds, there is an issue on the preference for metal binding to a convex surface versus a concave one. Some metal complexes bound on the convex face have been synthesized and characterized. Recently, our group achieved the first synthesis of the concave-bound η~6-complex, [CpFe(η~6-Sumanene)]PF6 (2a). The NMR spectroscopy and X-ray crystallographic analysis of 2a revealed the concave-selective binding structure in both solution and solid states. It is also the first example for the ferrocene complexes with π-bowls (Figure 1).