Transition-Metal-Free Click Polymerization Toward Poly(vinyl sulfide)s Endowed with AIE-Driven Noble Metal Sensing

Area of Science:

• Polymer Chemistry
• Materials Science
• Analytical Chemistry

Background:

• Developing sustainable polymerization methods is crucial for advanced materials.
• Metal-free catalysis offers greener alternatives in polymer synthesis.
• Sulfur-rich polymers possess unique optical and thermal properties.

Purpose of the Study:

• To report a novel transition-metal-free alkyne-thiol click polymerization.
• To synthesize poly(vinyl sulfide)s (PVSs) with high molecular weights and yields.
• To explore the potential of PVSs as fluorescent chemosensors for heavy metal detection.

Main Methods:

• Utilized a transition-metal-free alkyne-thiol click polymerization catalyzed by tBuOLi.
• Synthesized PVSs with controlled molecular weights and high yields.
• Investigated the optical properties (refractive index) and thermal stability (Td) of the synthesized PVSs.
• Integrated aggregation-induced emission (AIE) properties for chemosensor applications.

Main Results:

• Achieved 100% atom economy in the polymerization process.
• Synthesized PVSs with molecular weights up to 11,800 g/mol and yields up to 91%.
• PVSs exhibited high thermal stability (Td up to 293 °C) and high refractive indices (1.6383-1.8375).
• PVS aggregates demonstrated sensitive and selective detection of Pd2+ and Au3+ with fast response times (1-2 min for Pd2+).
• Achieved low limits of detection (LOD) for Pd2+ (7.11 × 10-7 M) and Au3+ (1.06 × 10-6 M).

Conclusions:

• The developed polymerization offers a sustainable route to sulfur-rich macromolecules.
• PVSs are promising materials for optical engineering due to their high refractive indices and thermal stability.
• The PVS-based fluorescent chemosensors provide a highly sensitive, selective, and robust platform for environmental monitoring of heavy metals.