Synthesis and Structure of Pd_4(μ-P~tBu_2)_2(μ -CS_2)(PPh_3)_2I_2, a Neutral Palladium(I) Derivative with a Hexacoordinate Carbon and a CS_2 Molecule Bridging Four Palladium Centers

摘要

The dinuclear CS_2 complex [Pd_2(μ-P~tBu_2)_(μ,η~2;η~2-CS_2)(PPh_3)_2]BF_4, (2)BF_4, reacts with Me_4NI to yield the neutral tetranuclear Pd(I) derivative Pd_4(μ-P~tBu_2)_2(μ_4-CS_2)(PPh_3)_2I_2 (4), which has been characterized by single- crystal X-ray diffraction. Its unusual molecular structure with a formally heaxcoordinate carbon atom, as well as that of (2)~+ with a planar tetracoordinate carbon can be explained on the basis of fragment MO considerations and EHMO model calculations.