Introduction of a (Ph3P)2Pt group into the rim of an open-cage fullerene by breaking a carbon-carbon bond.

Treatment of an open-cage fullerene, designated as MMK-9, with (Ph3P)4Pt in toluene solution at room temperature allows a (PPh3)2Pt unit to be incorporated into the rim of the cage so that it becomes an integral part of the carbon cage skeleton. The structure of the adduct has been determined by single crystal X-ray diffraction and reveals that the platinum atom has planar PtC2P2 coordination, rather than the usual η2-bonding to an intact C-C double bond of the fullerene.