From Polyhalides to Polypseudohalides: Chemistry Based on Cyanogen Bromide

Area of Science:

• Inorganic Chemistry
• Supramolecular Chemistry

Background:

• Pseudohalogens mimic halogen chemistry, but polypseudohalogen research is limited.
• Bromocyanogen (BrCN) exhibits a strong σ-hole, facilitating halogen bonding.

Purpose of the Study:

• To synthesize and characterize novel polypseudohalogen compounds.
• To explore the potential of these compounds as room-temperature ionic liquids (RTILs).

Main Methods:

• Single-crystal X-ray diffraction for structural determination.
• Raman spectroscopy and quantum-chemical calculations for anion characterization.
• NMR spectroscopy (¹³C and ¹⁵N) for solution behavior and RTIL studies.

Main Results:

• Successful synthesis and characterization of [Br(BrCN)]− and [Br(BrCN)3]− anions.
• Structural analysis revealed a linear [Br(BrCN)]− and a distorted pyramidal [Br(BrCN)3]− anion.
• Polypseudohalogen-based RTILs demonstrated the ability to dissolve elemental gold.

Conclusions:

• Novel polypseudohalogen anions were synthesized and structurally elucidated.
• These compounds can form room-temperature ionic liquids with potential applications in gold dissolution and metal recycling.