Exceptionally Long-Lived Photodriven Multi-Electron Storage without Sacrificial Reagents

Area of Science:

• Photochemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Molecular pentads are key components in artificial photosynthesis.
• Efficient multi-electron transfer is essential for solar energy conversion technologies.
• Stabilizing photogenerated intermediates is critical for device longevity.

Purpose of the Study:

• To investigate the photoexcitation of a molecular pentad in the presence of Sc³⁺.
• To understand the mechanism of light-driven electron accumulation on a quinone unit.
• To explore the role of Lewis acid-base interactions in stabilizing photoproducts.

Main Methods:

• Photoexcitation of a molecular pentad in acetonitrile (CH₃ CN).
• Utilizing two Ru(bpy)₃²⁺ complexes for intramolecular electron sensitization.
• Employing Sc³⁺ as a Lewis acid to interact with the quinone dianion.

Main Results:

• Formation of a stable quinone dianion with a millisecond timescale lifetime.
• Intramolecular electron accumulation sensitized by Ru(bpy)₃²⁺ complexes.
• Demonstration of Lewis acid-base interactions enhancing photoproduct stability.

Conclusions:

• Sc³⁺ significantly stabilizes the quinone dianion through Lewis acid-base interactions.
• Intramolecular multi-electron transfer is achievable without sacrificial reagents.
• The findings are relevant for developing efficient solar energy conversion systems.