Pyridine-tetrathiafulvalene-terminated poly(N,N-dimethylacrylamide)s for specific and selective complexation and detection of Pb2+ ions

Abstract

Pyridine (Py) and tetrathiafulvalene (TTF) moieties are strategically linked to the α-chain-ends of poly(N,N-dimethyacrylamide)s (PDMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization and post-RAFT polymerization modification. Blue LED light-initiated RAFT polymerization, using a carboxylic acid-functionalized RAFT agent, enables the synthesis of carboxylic acid end-terminated PDMAs with precise molecular weights control and narrow molecular weight distributions (Ð ≤ 1.23). This irradiation process operates efficiently at 20 °C without external initiator and solvent, achieving near-total N,N-dimethyacrylamide conversion (ρ = 92%). The high fidelity of the carboxylic acid end-terminated PDMAs allows their quantitative post-polymerization modification (f = 93%) in the presence of alcohol-functionalized Py-TTF dyad. The resulting Py-TTF end-functionalized PDMAs exhibit complexing and electroactive properties. Thoroughly characterization via colorimetric tests, UV–Vis analyses and cyclic voltammetry measurements reveal their specific and selective complexation and detection ability, particularly for Pb²⁺ ions.

Graphical abstract

Blue light-induced RAFT polymerization of N,N-dimethylacrylamide (DMA) in bulk proceeds without solvent, without exogenous initiator, at room temperature with near-total conversions, and enables the preparation of pyridine-tetrathiafulvalene-terminated PDMAs for specific and selective complexation and detection of Pb²⁺ ions in organic and aqueous solution.