Single-Electron Transfer in Frustrated Lewis Pair Chemistry

Area of Science:

• Organometallic Chemistry
• Main-Group Chemistry
• Supramolecular Chemistry

Background:

• Frustrated Lewis pairs (FLPs) are known for activating small molecules.
• Recent studies suggest single-electron transfer (SET) may be involved in FLP chemistry, leading to radical formation.

Purpose of the Study:

• To investigate radical formation in FLP systems reacting with H2, Ph3SnH, and TCQ.
• To determine the mechanism of SET events in FLP chemistry, specifically whether direct SET to B(C6F5)3 occurs.

Main Methods:

• Experimental studies of FLP reactions.
• Computational investigations of reaction mechanisms.
• Analysis of SET pathways in FLP systems.

Main Results:

• Reactions of H2 and Ph3SnH with P/B FLP systems do not involve radical mechanisms.
• Reaction of FLPs with TCQ proceeds via SET, facilitated by Lewis acid coordination to the substrate.
• SET from Lewis base to Lewis acid-substrate adduct may be common in other radical FLP chemistry.

Conclusions:

• The mechanism of radical formation in FLP chemistry is substrate-dependent.
• Lewis acid coordination to the substrate is crucial for SET with TCQ.
• Understanding SET pathways provides design principles for radical main-group chemistry.