Copolymer of Fluorene and Triphenylamine Moieties: Direct and Post‐Functionalization Strategy, Structural Characterization, and Chemosensoring Behavior

To prepare a copolymer of fluorene and triphenylamine bearing imidazole groups in the side chain, two synthetic approaches have been designed: the direct copolymerization of the corresponding monomers, and the post‐functionalization of a precursor polymer. Unexpectedly, the direct copolymeriztion strategy was better. The chemosensing behavior of P2 was carefully studied, the fluorescence of which could be quenched by Cu2+ ions at concentrations as low as 8 × 10−6 mol · L−1 in dilute solutions. By utilizing the much higher stability constant of the complex of CN− and Cu2+, the quenched fluorescence of the solution of P2 by Cu2+ ions could be recovered upon the addition of a trace amount of CN− anions, with a detection limit as low as 1.8 × 10−5 mol · L−1 (0.47 ppm), making P2 a new sensitive cyanide probe. magnified image