[Au(C₆ F₅ )₃ (PPh₂ H)]: A Precursor for the Synthesis of Gold(III) Phosphide Complexes

Area of Science:

• Inorganic Chemistry
• Crystallography
• Organometallic Chemistry

Background:

• The study investigates the covalent radii of coinage metal ions, specifically gold(I) and silver(I).
• Understanding covalent radii is crucial for predicting bonding and structural properties in coordination complexes.
• Previous data on the covalent radius of Au(I) is limited, necessitating experimental determination.

Purpose of the Study:

• To experimentally determine and compare the covalent radii of gold(I) and silver(I) ions.
• To synthesize and characterize novel mixed gold(III)-metal phosphide complexes.
• To establish a relationship between metal identity and structural parameters in isostructural compounds.

Main Methods:

• Synthesis of mixed Au(III)-M phosphide complexes using [Au(C6F5)3(PPh2H)].
• Single-crystal X-ray diffraction analysis of isostructural complexes with M=Au and M=Ag.
• Comparison of structural parameters, specifically metal-ligand bond lengths, to infer covalent radii.

Main Results:

• The covalent radius of Au(I) was found to be approximately 0.07 Å smaller than that of Ag(I).
• Isostructural complexes of the type [N(PPh3)][{Au(C6F5)3(μ-PPh2)}2M] (M=Au, Ag) were successfully synthesized and characterized.
• The synthesis utilized [Au(C6F5)3(PPh2H)], a novel gold complex featuring a secondary phosphane ligand.

Conclusions:

• The experimental data confirms a difference in covalent radii between Au(I) and Ag(I).
• The synthesized mixed-metal phosphides serve as valuable model systems for studying electronic and structural effects in coinage metal compounds.
• This work provides a foundation for further investigations into the chemistry of gold and silver complexes with phosphine ligands.