A New Disubstituted Polyacetylene Bearing Pyridine Moieties: Convenient Synthesis and Sensitive Chemosensor toward Sulfide Anion with High Selectivity

To develop sensitive and selective S 2– chemosensors, a new disubstituted polyacetylene ( P2 ) bearing pyridine moieties in the side chains was prepared conveniently through a postfunctional method, the strong green fluorescence of which could be completely quenched by Cu 2+ ions at the concentration as low as 2.0 × 10 –6 mol/L in diluted solutions. Based on the displacement strategy, by utilizing the much higher stability constant of the complex of S 2– and Cu 2+, the quenched fluorescence of the solution of P2 by Cu 2+ ions could recover upon the addition of trace S 2– anions, with the detection limit down to 5.0 × 10 –7 mol/L. Moreover, no interference were observed from other anions, including SO 3 2–, HSO 3 –, SO 4 2–, ClO 4 –, I –, Br –, Cl –, F –, IO 3 –, HPO 4 2–, PO 4 3–, C 2 O 4 2–, S 2 O 3 2–, CO 3 2–, AcO –, CN –, and P 2 O 7 4–, making P2 a novel, sensitive, and selective sulfide probe.