Tetracyanido(difluorido)phosphates M(+) [PF2 (CN)4 ](.)

Area of Science:

• Inorganic Chemistry
• Materials Science

Background:

• Hexafluorophosphate (PF6-) salts are common precursors in inorganic synthesis.
• Organosilicon compounds like trimethylsilyl cyanide (Me3SiCN) are versatile reagents.

Purpose of the Study:

• To develop a synthetic route for a new class of phosphorus-containing anions.
• To characterize the structure and properties of novel salts and ionic liquids incorporating this anion.

Main Methods:

• Systematic optimization of reaction conditions (temperature, pressure, stoichiometry).
• Synthesis and isolation of various metal and organic salts of the target anion.
• X-ray crystallography for structural determination of synthesized salts.
• Nuclear Magnetic Resonance (NMR) spectroscopy (31P and 19F) for structural confirmation in solution.
• Preparation and characterization of an ionic liquid derived from the new anion.

Main Results:

• Successful synthesis and isolation of salts containing the unprecedented [PF2(CN)4](-) ion in good yields.
• Crystal structure determination revealed the exclusive formation of the cis isomer.
• Solution NMR data corroborated the cis isomer formation.
• A room temperature ionic liquid, EMIm[PF2(CN)4], was prepared with notably low viscosity.

Conclusions:

• A novel synthetic pathway to the [PF2(CN)4](-) anion has been established.
• The synthesized salts and ionic liquids represent a new family of compounds with potential applications.
• The low viscosity of the EMIm[PF2(CN)4] ionic liquid suggests utility in various chemical processes.