Planar PtPd₃ Complexes Stabilized by Three Bridging Silylene Ligands

Area of Science:

• Organometallic Chemistry
• Materials Science
• Catalysis

Background:

• Exploration of heterobimetallic complexes is crucial for developing novel materials and catalysts.
• Silylene ligands play a significant role in stabilizing unique metal cluster structures.
• Understanding metal-silicon bonding is key to predicting reactivity and electronic properties.

Purpose of the Study:

• To synthesize and characterize a novel heterobimetallic platinum-palladium complex supported by diphenylsilylene ligands.
• To investigate the structural and electronic properties of the synthesized complex and its derivatives.
• To explore the reactivity of the complex with silylating agents and its adducts with copper and silver halides.

Main Methods:

• Synthesis of a heterobimetallic PtPd3 complex, [Pt{Pd(dmpe)}3(μ3-SiPh2)3], from mononuclear Pt and Pd precursors.
• Reaction of the complex with PhSiH3 and Ph2SiH2 to form tetranuclear and octanuclear complexes.
• Formation and characterization of CuI and AgI adducts, followed by kinetic studies of halide elimination.

Main Results:

• Successful synthesis of the heterobimetallic PtPd3 complex and its comparison to a tetrapalladium analogue.
• Formation of new tetranuclear and octanuclear complexes with silyl and hydride ligands.
• Characterization of M-Si bond lengths and 29Si NMR chemical shifts, indicating intermediate bonding characteristics.
• Adducts with CuI and AgI were formed and shown to regenerate tetrametallic complexes upon heating or diphosphine addition.
• Kinetics experiments revealed faster AgI elimination from its adduct compared to CuI elimination.

Conclusions:

• The synthesized heterobimetallic PtPd3 complex exhibits unique structural and electronic properties.
• The complex serves as a precursor to novel multinuclear platinum-palladium-silicon clusters.
• The reactivity of its halide adducts suggests potential applications in catalysis or materials synthesis.