Non-coordinated and Hydrogen Bonded Phenolate Anions as One-Electron Reducing Agents.

Area of Science:

• Organic Chemistry
• Inorganic Chemistry
• Electrochemistry

Background:

• Phenolate anions are crucial intermediates in various chemical reactions.
• Understanding their coordination behavior and redox properties is essential for designing new synthetic methodologies.
• Powerful bases are needed for the selective deprotonation of alcohols to form non-coordinated anions.

Purpose of the Study:

• To synthesize non-coordinated electron-rich phenolate anions.
• To investigate the impact of hydrogen bonding on their redox potentials.
• To explore their utility as reducing agents and in the activation of sulfur hexafluoride.

Main Methods:

• Deprotonation of alcohols using a perethyl tetraphosphazene base (Schwesinger base).
• Selective preparation of anionic phenol-phenolate and phenolate hydrates.
• Electrochemical analysis to determine redox potentials.
• Synthesis and characterization of a tetracyanoethylene radical anion salt.
• Reactions with sulfur hexafluoride.

Main Results:

• Successfully synthesized non-coordinated phenolate anions.
• Demonstrated that hydrogen bonding decreases redox potentials.
• Phenolate anions exhibit redox potentials comparable to zinc metal, acting as organic zinc mimics.
• Utilized phenolates as reducing agents for radical anion generation.
• Achieved activation of sulfur hexafluoride, forming either fluoride or pentafluorosulfanide salts.

Conclusions:

• The use of phosphazene bases enables the selective synthesis of non-coordinated phenolate anions.
• Hydrogen bonding significantly influences the electrochemical properties of these anions.
• Phenolate anions show promise as versatile reagents in organic synthesis and materials science.