Synthesis and Characterization of Bis-Triruthenium Cluster Derivatives of an All Equatorial [60]Fullerene Tetramalonate

Exohedral metal-C₆₀ complexes exhibit unique physicochemical properties as a result of the metal cluster centers.¹ This is important in the study of the reactivity and electrochemical properties of exohedral metal-C₆₀ complexes, as it might result in the development of new nanomaterials.²

Kräutler et al. developed the orthogonal transposition method to synthesize C₆₀ tetrakis-adducts with all addends located on the equatorial belt and the trans-1 positions available for further functionalizations.³ The presence of the tetrakis[di(ethoxycarbonyl)methano] groups should limit the number of possible bis-adduct regioisomers observed. We report that tetrakis[di(ethoxycarbonyl)-methano]-C₆₀ reacts with triruthenium clusters to form the first anti-isomer C₆₀-metal cluster complex : anti-[Ru₃(CO)₉]₂{μ₃-η²,η²,η²-C₆₀[C(COOC₂H₅)₂]₄}. The two triruthenium groups are found in either an anti or a syn orientation, as determined by NMR. Only the anti form was characterized by X-ray crystallography, see structure below.

References

1. K. Lee, H. Song and J. T. Park, Acc. Chem. Res. 2003, 36, 78.

2.  Y.-J. Cho, T. K. Ahn, H. Song, K. S. Kim, C. Y. Lee, W. S. Seo, K. Lee,  S. K. Kim, D. Kim and J. T. Park, J. Am. Chem. Soc. 2005, 127, 2380.

3. R. Schwenninger, T. Müller and B. Kräutler, J. Am. Chem. Soc. 1997, 119, 9317.