On the coordination chemistry of corannulene, the smallest “buckybowl”

A variety of methods, conventional and non-conventional, are used in attempts to prepare the compounds (η6-corannulene)M(CO)3 (M = Cr, Mo, W), all unsuccessful. Conventional methods are also utilized in attempts to prepare the compound [CpFe(η6-corannulene)]PF6, but these result in mixtures of cationic CpFe(arene) complexes containing partially hydrogenated corannulene; similar results have been reported for other polyaromatic hydrocarbons. DFT calculations on the compound (η6-corannulene)Cr(CO)3 suggest that the (η6-corannulene)-Cr linkage is only a few kcal/mol weaker than the corresponding bond in (η6-benzene)Cr(CO)3, implying that failures in syntheses arise from kinetic, not thermodynamic problems.

An extensive series of attempts to synthesize the compounds (η6-corannulene)M(CO)3 (M = Cr, Mo, W), utilizing virtually every standard and non-standard procedure known for the synthesis of compounds of the type (η6-arene)M(CO)3, have all failed miserably. DFT calculations suggest that the η6-corannulene–Cr bond of (η6-corannulene)Cr(CO)3 is only marginally weaker than the correspond arene–metal bond in the very stable (η6-benzene)Cr(CO)3, and it seems that the reasons for synthetic failures are kinetic in nature.Figure optionsDownload as PowerPoint slide