Bidentate selenium-based chalcogen bond catalyzed cationic polymerization of p-methoxystyrene

Area of Science:

• Polymer Chemistry
• Catalysis
• Organoselenium Chemistry

Background:

• Living cationic polymerization is crucial for synthesizing well-defined polymers.
• Selenium-based catalysts for non-covalent bond catalysis in polymerization are underexplored.
• Developing robust and environmentally tolerant catalysts remains a key challenge.

Purpose of the Study:

• To investigate the efficacy of a bidentate selenium bond catalyst in living cationic polymerization.
• To achieve controlled polymerization of p-methoxystyrene (pMOS) under ambient conditions.
• To elucidate the catalytic mechanism involving reversible activation of dormant covalent bonds.

Main Methods:

• Utilized a novel bidentate selenium compound as a Lewis acid catalyst.
• Performed cationic polymerization of p-methoxystyrene (pMOS) at room temperature.
• Conducted secondary monomer feeding experiments and Density Functional Theory (DFT) analysis.

Main Results:

• Achieved controlled cationic polymerization of pMOS yielding polymers with predictable molecular weights up to 23.3 kDa.
• Obtained polymers with narrow molecular weight distributions, indicating a living polymerization process.
• Demonstrated catalyst's water tolerance and effectiveness under environmental conditions.

Conclusions:

• The bidentate selenium bond catalyst effectively mediates living cationic polymerization of pMOS.
• The catalyst operates via reversible activation of dormant C-OH bonds, enabling controlled polymer growth.
• This work expands the scope of selenium-based catalysts in advanced polymerization techniques.