Zwitterionic Heavier Pnictinidenes in Redox Catalysis

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Main Group Chemistry

Background:

• Zwitterionic compounds offer unique electronic properties.
• Heavier pnictogens (Sb, Bi) are crucial in catalysis.
• N-heterocyclic carbene ligands are versatile in stabilizing reactive species.

Purpose of the Study:

• To synthesize and characterize novel zwitterionic heavier pnictogen species.
• To investigate the electronic properties and reactivity of these compounds.
• To explore their potential as redox catalysts.

Main Methods:

• Synthesis of zwitterionic pnictogen species using bis(N-heterocyclic carbene)borate ligands.
• Isolation and characterization of antimony (Sb) and bismuth (Bi) compounds in multiple oxidation states.
• Computational analysis (e.g., DFT) to understand electronic structure and reactivity.
• Testing catalytic activity in hydrodefluorination and dehydrogenative thiolation reactions.

Main Results:

• Successful isolation of stable zwitterionic Sb and Bi species in various oxidation states.
• Computational studies revealed cationic character and unique electronic properties, enhancing nucleophilicity and stability.
• Demonstrated participation in oxidative addition and reductive elimination.
• Exhibited redox catalytic activity in hydrodefluorination, acting as a cationic pnictinidene catalyst.
• Reported a novel dehydrogenative thiolation of silanes.

Conclusions:

• This work expands the chemistry of low-valent pnictogens.
• Introduced a new class of zwitterionic heavier pnictogen compounds with tunable electronic properties.
• Established a novel platform for main group redox catalysis, showcasing reactivity beyond traditional ligand constraints.