Two thieno[3,4b]pyrazine‐containing copolymers: synthesis,characterization, and application in mercury ions detection

Two alternative copolymers of thieno3,4b]pyrazine (TPZ) and triphenylamine (TPA) or phenylene (Ph), P(TPA‐TPZ) and P(Ph‐TPZ), were synthesized by Wittig–Horner polycondensation and characterized by ¹H NMR, elemental analysis, GPC, TGA, cyclic voltammetry, UV–Vis absorption, and photoluminescence (PL) spectroscopy. The polymers are soluble in common organic solvents and possess good thermal stability. Both of them shows strong solvatochromism phenomenon when dissolved in different solvents. The fluorescence of the copolymer solutions is efficiently quenched upon the addition of Hg²⁺, indicating that the two copolymers could be good Hg²⁺ detectors. More interestingly, the copolymers show high selectivity for the Hg²⁺ detection and P(TPA‐TPZ) shows higher sensitivity and selectivity toward the Hg²⁺ detection than P(Ph‐TPZ) does in the presence of other competing metal ions. The results imply that the conjugated polymers (CPs) containing the thieno3,4b]pyrazine moiety are promising materials for chemosensors. Copyright © 2009 John Wiley & Sons, Ltd.