Two Metal Centers Bridging Two C₆₀ Cages as a Wide Passage for Efficient Interfullerene Electronic Interaction

The reaction of Ir4(CO)8(PMe3)4 with excess C60 in refluxing 1,2-dichlorobenzene, followed by treatment by CNR (R = CH2C6H5) at 70 °C, affords a fullerene−metal sandwich complex Ir4(CO)3(μ4-CH)(PMe3)2(μ-PMe2)(CNR)(μ-η2,η2-C60)(μ4-η,η1,η,η2-C60) (1), which exhibits an interesting structural feature of two metal atoms bridging the two C60 centers as well as the first example of a μ4-η1,η1,η2,η2-C60 bonding mode. Compound 1 has been characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction study. A cyclic voltammetry study reveals strong electronic communication between the two C60 centers in 1, which is due to the presence of a wide channel of two metal centers between the two C60 cages for efficient electronic interaction.