Carbazole-Containing Conjugated Copolymers as Colorimetric/Fluorimetric Sensor for Iodide Anion

A series of conjugated poly(p-phenylene carbazole) copolymers, poly(N-hexyl-3,6-carbazole-alt-2,5-bisdodecyloxyphenylene) [P1], poly(N-ethylhexyl-3,6-carbazole-alt-2,5-bisdodecyloxyphenylene) [P2], and poly(N-dodecyl-3,6-carbazole-alt-2,5-bisdodecyloxyphenylene) [P3] were prepared by using palladium-catalyzed Suzuki coupling reactions. All copolymers were characterized by means of FT-IR, GPC, 1H and 13C NMR, UV−vis, fluorescence spectroscopy, and X-ray powder diffraction patterns. All copolymers were soluble in common organic solvents, exhibited good thermal stability up to 390 °C, and showed UV−vis absorbance and fluorescence maxima around 328 and 394 nm, respectively. The polymers P1−P3 differed in N-alkyl substitution, i.e., n-hexyl (for P1), n-ethylhexyl (for P2), and n-dodecyl (for P3) groups. In addition, a third monomer, 2,5-substituted pyridine for poly(N-ethylhexyl-3,6-carbazole-co-2,5-didodecyloxy phenylene-co-2,5-pyridine) (P4) and dialkylated fluorene for poly(N-ethylhexyl-3,6-carbazole-co-2,5...