Reductive Catenation of Phosphine Antimony Complexes.

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Materials Science

Background:

• Triarylphosphines are versatile ligands in coordination chemistry.
• Fluoroantimony(III) triflates are reactive precursors for antimony compounds.
• Reductive elimination and catenation are key reaction pathways in inorganic synthesis.

Purpose of the Study:

• To synthesize novel cationic antimony compounds.
• To explore the reactivity of triarylphosphines with fluoroantimony(III) triflates.
• To demonstrate a new reductive catenation method.

Main Methods:

• Reaction of triarylphosphines with fluoroantimony(III) triflates.
• Isolation and characterization of phosphine antimony(III) complexes.
• Observation of spontaneous reductive elimination and subsequent catenation.

Main Results:

• Formation of phosphine antimony(III) complexes.
• Spontaneous reductive elimination of fluorophosphonium cations.
• Catenation of phosphine antimony(I) complexes to form cationic bicyclic antimony compounds, [(R3P)4Sb6](4+).
• The compounds feature a bicyclo[3.1.0]hexastibine framework stabilized by phosphine ligands.
• An unprecedented 14-electron redox process was observed.

Conclusions:

• The study reports the first examples of cationic antimony bicyclic compounds.
• The reductive catenation method is shown to be general for synthesizing such structures.
• The findings expand the scope of antimony cluster chemistry and redox processes.