Metal coordination of phosphoniocarbynes

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Inorganic Synthesis

Background:

• Exploration of polynuclear metal complexes with unique bridging ligands is crucial for advancing catalysis and materials science.
• Phosphoniocarbyne ligands offer versatile coordination modes, enabling the construction of novel metal frameworks.
• Tungsten-based complexes with pyrazolylborate ligands (Tp*) are known for their stability and tunable electronic properties.

Purpose of the Study:

• To synthesize and characterize novel heterobi- and tetrametallic phosphoniocarbyne bridged complexes.
• To investigate the reactivity of these complexes with different metal precursors.
• To explore the structural and bonding aspects of the resulting tungstaplatinacyclopropene core.

Main Methods:

• Reaction of a mononuclear terminal phosphoniocarbyne tungsten complex with gold, copper, and platinum precursors.
• Utilized tetrahydrothiophene (THT) and dimethyl sulfide (SMe2) as auxiliary ligands.
• Employed 1,5-cyclooctadiene (COD) and norbornene (nbe) as ancillary ligands.
• Characterization of products using spectroscopic methods and computational analysis.

Main Results:

• Successful synthesis of heterobi- and tetrametallic complexes: [WAu(μ-CPMe2Ph)Cl(CO)2(Tp*)]+, [W2Cu2(μ-CPMe2Ph)2(μ-Cl)2(CO)4(Tp*)2]2+, and [WPt(μ-CPMe2Ph)(COD)(CO)2(Tp*)]+.
• The COD ligand in the platinum complex is labile and can be replaced by isonitriles, yielding [WPt(μ-CPMe2Ph)(CNR)2(CO)2(Tp*)]+.
• The tungstaplatinacyclopropene core structure and bonding were computationally investigated.

Conclusions:

• Demonstrated the feasibility of constructing complex multinuclear phosphoniocarbyne bridged systems.
• Highlighted the reactivity of the COD ligand in platinum complexes for further functionalization.
• Provided insights into the electronic structure and bonding of the key tungstaplatinacyclopropene motif.