Novel BODIPY-Based Photobase Generators for Photoinduced Polymerization

Area of Science:

• Organic Chemistry
• Polymer Science
• Photochemistry

Background:

• Photobase generators (PBGs) offer spatiotemporal control of base release for initiating polymerization.
• Existing PBGs have limitations including short absorption wavelengths and inefficient base release, hindering photopolymerization efficiency.
• There is a need for visible-light-triggered PBGs capable of releasing strong bases efficiently.

Purpose of the Study:

• To develop novel BODIPY-based visible-light-sensitive photobase generators (PBGs).
• To enable efficient light-induced activation of thiol-ene Michael addition reactions and polymerization.
• To improve the efficiency of base release and polymerization rates using the heavy atom effect.

Main Methods:

• Design and synthesis of two novel BODIPY-based PBGs.
• Conjugation of BODIPY light-sensitive protecting groups with tetramethylguanidine (TMG), a strong base.
• Exploitation of the heavy atom effect to enhance TMG release and polymerization kinetics.

Main Results:

• The novel BODIPY-based PBGs demonstrate efficient visible-light-triggered release of TMG.
• These PBGs exhibit extraordinary activity in thiol-ene Michael addition-based polymerization.
• Successful application in surface coating and polymer network formation with various thiol and vinyl monomers.

Conclusions:

• The developed BODIPY-based PBGs are highly effective visible-light-sensitive initiators for anionic polymerization.
• The heavy atom effect significantly enhances the efficiency of base release and polymerization.
• These PBGs offer a promising platform for advanced photopolymerization applications, including surface modification and material fabrication.