An Alternative Copolymer of Carbazole and Thieno[3,4b]‐Pyrazine: Synthesis and Mercury Detection
2008; Wiley; Volume: 18; Issue: 18 Linguagem: Inglês
10.1002/adfm.200800567
ISSN1616-3028
AutoresYingping Zou, Meixiu Wan, Guangyi Sang, Mingfu Ye, Yongfang Li,
Tópico(s)Conducting polymers and applications
ResumoAbstract A donor‐ π ‐acceptor (D‐ π ‐A) alternative copolymer of carbazole and thieno[3,4b]‐pyrazine [P(CZ‐TPZ)] is synthesized through a Wittig–Horner reaction. In dilute THF solution, the absorption spectrum of P(CZ‐TPZ) shows two absorption peaks at 306 and 452 nm, respectively, and the PL spectrum of the polymer solution displays a PL peak maximum at 543 nm. The polymer possesses relatively high sensitivity and selectivity for Hg 2+ detection. Upon addition of Hg 2+ into its THF solution (containing 0.3% CH 3 CN), P(CZ‐TPZ) exhibits a new absorption peak at 560∼600 nm and its emission was quenched dramatically. The Hg 2+ detection shows high selectivity in comparison with the other cations of Na + , K + , Mg 2+ , Ba 2+ , Al 3+ , Cu 2+ , Cd 2+ , Pb 2+ , Ni 2+ , Mn 2+ , and Co 2+ . The Hg 2+ detection limit of the polymer solution by emission quenching is found to be 1 × 10 −7 mol L −1 . P(CZ‐TPZ) also shows a selective chromogenic behavior toward Hg 2+ with color change of the solution from yellow to blue dark which can be detected with the naked eye, the detection limit reaches 1 × 10 −6 mol L −1 with a 1 × 10 −4 mol L −1 polymer solution. The absorption and PL spectral change can be resumed after adding thiourea, therefore the sensing ability of the polymer is re‐usable with the treatment of thiourea. The results indicate that P(CZ‐TPZ) is a promising chemosensor for the Hg 2+ detection.
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