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

A novel transition-metal-free alkyne–thiol click polymerization with 100% atom economy is reported. Using tBuOLi as a catalyst at 80 °C, the polymerization efficiently yields poly(vinyl sulfide)s (PVSs) with molecular weights up to 11,800 g/mol and yields up to 91%. These sulfur-rich polymers exhibit high thermal stability (Td up to 293 °C) and high refractive indices (1.8375–1.6383) across the visible range. By integrating abundant sulfur coordination sites with aggregation-induced emission (AIE) properties, the PVS aggregates serve as high-performance fluorescent chemosensors. The sensor enables exclusive, sensitive trace detection of Pd2+ and Au3+ with remarkable anti-interference capability and pH robustness (pH 1–7). Notably, an ultrafast response (1–2 min) for Pd2+ is achieved, with limits of detection (LOD) reaching 7.11 × 10−7 M for Pd2+ and 1.06 × 10−6 M for Au3+, and corresponding limits of quantification (LOQ) reaching 2.37 × 10−6 M and 3.53 × 10−6 M, respectively. This methodology offers a sustainable route to heteroatom-rich macromolecules for next-generation optical engineering and environmental monitoring.