Precise cooperative sulfur placement leads to semi-crystallinity and selective depolymerisability in CS₂/oxetane...

Area of Science:

• Polymer Chemistry
• Organometallic Catalysis
• Main-Group Chemistry

Background:

• Carbon disulfide (CS₂) offers a route to sulfur-rich polymers but faces challenges in controlled polymerization.
• Existing methods for CS₂ copolymerization with oxetanes suffer from low selectivity and byproduct formation.
• Understanding main-group element influence on polymer properties is crucial for material design.

Purpose of the Study:

• To develop a selective catalytic system for the ring-opening copolymerization of CS₂ and oxetanes.
• To investigate the impact of sulfur incorporation on polymer properties and degradability.
• To achieve high sequence selectivity in the synthesis of poly(dithiocarbonates).

Main Methods:

• Cooperative catalysis using a Cr(III)/K system for CS₂ and oxetane copolymerization.
• Analysis of polymer microstructure to determine linkage selectivity.
• Investigation of polymer depolymerization and recyclability.

Main Results:

• The Cr(III)/K catalyst achieved high linkage selectivity, producing poly(dithiocarbonates) with minimal byproducts.
• Sulfur incorporation shifted the polymerization equilibrium, facilitating depolymerization.
• The synthesized polymers exhibited sequence selectivity, enabling the formation of semi-crystalline materials.
• Chemoselective depolymerization yielded cyclic dithiocarbonates, useful as monomers.

Conclusions:

• Cooperative catalysis provides a powerful strategy for synthesizing novel main-group rich polymers.
• Selective polymerization is key to accessing degradable, high-performance sulfur-containing polymers.
• This approach opens avenues for creating advanced materials with tailored chemical and physical properties.