Well-defined boron-containing polymeric lewis acids.

Area of Science:

• Polymer Chemistry
• Organoboron Chemistry
• Materials Science

Background:

• Polymeric Lewis acids are valuable materials with diverse applications.
• Developing controlled synthesis routes for functional polymers remains a key challenge.

Purpose of the Study:

• To report a general new route to well-defined polymeric Lewis acids.
• To synthesize and characterize novel boron-containing polymers.
• To explore the tunable Lewis acidity of these new polymeric materials.

Main Methods:

• Atom transfer radical polymerization (ATRP) of 4-(trimethylsilyl)styrene to obtain silylated polystyrene (PS-Si).
• Quantitative borylation of PS-Si using BBr3 to yield poly(4-dibromoborylstyrene) (PS-B).
• Reaction of PS-B with nucleophiles, including Cu(C6F5), to generate new polymeric Lewis acids.

Main Results:

• Well-defined silylated polystyrene (PS-Si) with controlled molecular weight and low polydispersity (PDI < 1.15) was synthesized.
• A novel soluble boron-containing polymeric Lewis acid, PS-B, was successfully prepared.
• PS-B demonstrated reactivity with nucleophiles, serving as a precursor to polymers with variable Lewis acidity.
• The first polymeric analogue of tris(pentafluorophenyl)borane, poly[4-bis(pentafluorophenyl)borylstyrene], was synthesized.

Conclusions:

• A general and efficient route to well-defined polymeric Lewis acids via borylation of silylated polymers has been established.
• The synthesized boron-containing polymers exhibit tunable Lewis acidity, offering a platform for new material development.
• This work introduces novel polymeric Lewis acids with potential applications in catalysis and materials science.