HYPERCOORDINATE CARBON IN BIS(TRIMETHYLSILYL)TRIS[(TRIPHENYLPHOSPHINE)AURIO(I)]METHANIUM TETRAFLUOROBORATE

[Bis(trimethylsilyl)methyl](triphenylphosphine)gold(I) has been synthesized according to literature methods and its crystal structure determined. Treatment of this compound with [(Ph3P)Au]3O+BF4-in dichloromethane gives small amounts of the compound (Me3Si)2C[Au(PPh3)2]2 together with the novel trinuclear complex {Me3Si)2C[Au(PPh3)]3}+BF4-. The structure of the cation features the pentacoordinate carbon atom in a distorted-trigonal-bipyramidal environment with two silicon atoms in equatorial positions. Short axial/equatorial Au...Au contacts indicate peripheral metal-metal bonding.