Tweezer Dyads for H-Bond Assisted Cooperativity in Tandem Uncaging Systems

Area of Science:

• Photochemistry
• Organic Synthesis
• Biomedical Engineering

Background:

• Tandem uncaging systems enhance photosensitivity for two-photon (2P) photorelease.
• Current methods suffer from complex multi-step synthesis, limiting accessibility.

Purpose of the Study:

• To design efficient and accessible tandem uncaging systems.
• To improve two-photon (2P) photorelease efficiency through optimized molecular design.

Main Methods:

• Utilized click chemistry for convenient building block assembly.
• Incorporated H-bonding to induce proximity between antenna and photolabile protecting groups (PPGs).
• Investigated photoinduced electron transfer (PeT) as a cooperative mechanism.

Main Results:

• Developed a tweezer-shaped platform for stepwise clicking of antenna and PPGs.
• Identified optimal redox potentials in the mDEAC dyad for efficient PeT and reduced charge recombination.
• Achieved enhanced uncaging quantum yield (Φu=0.38) and high 2P photo-sensitivity (240 GM at 710 nm).

Conclusions:

• Efficient tandem uncaging systems can be constructed using click chemistry and H-bonding.
• Optimized molecular design, particularly redox potentials, is crucial for high performance.
• The developed system offers significant advantages for 2P photorelease applications in the near-infrared window.