Boosting Photoredox Catalysis Using a Two-Dimensional Electride as a Persistent Electron Donor.

Area of Science:

• Solid-state chemistry
• Photocatalysis
• Organic synthesis

Background:

• Electrides are solid-state electron donors with potential in organic synthesis.
• Their instability in organic solvents limits efficient electron transfer and application.
• Controlling electron donation from electrides remains a significant challenge.

Purpose of the Study:

• To develop an efficient reductive transformation strategy using electrides.
• To overcome the limitations of electride decomposition in organic solvents.
• To utilize the superior electron-donating ability of electrides in photocatalysis.

Main Methods:

• Combining a stable two-dimensional [Gd2C]2+·2e- electride with cyclometalated Pt(II) complex photocatalysts.
• Utilizing moderate alcoholysis in 2,2,2-trifluoroethanol for controlled electron release from the electride.
• Adsorbing Pt(II) complexes onto the electride surface for rapid electron capture upon photoexcitation.
• Employing the photoredox catalysis principle for reductive generation of benzyl radicals.

Main Results:

• Achieved persistent electron donation from the [Gd2C]2+·2e- electride via controlled alcoholysis.
• Demonstrated rapid electron capture by Pt(II) complexes (10^7 s^-1) upon photoexcitation.
• Showcased the stability of the one-electron-reduced Pt complex for substrate electron delivery.
• Suppressed charge recombination due to irreversible electride disruption after electron transfer.

Conclusions:

• Developed an efficient photoredox catalysis system combining stable electrides and Pt(II) complexes.
• Successfully demonstrated controlled electron transfer from electrides for organic synthesis.
• The system enables the reductive generation of benzyl radicals from benzyl halides, useful for dehalogenation and homocoupling reactions.