Triphenylamine-based fluorescent conjugated copolymers with pendant terpyridyl ligands as chemosensors for metal ions

Two well-defined triphenylamine-based fluorescent conjugated copolymers with pendant terpyridyl ligands were synthesized through Suzuki coupling polymerization and were further characterized by ¹H-NMR, ¹³C-NMR, gel permeation chromatography, Infrared, and UV-vis spectra. Polymer P-1, terpyridine-bearing poly(triphenylamlne-alt-fluorene) with a high fluorescence quantum yield (62%) shows much higher sensitivities toward Fe ³⁺, Ni²⁴⁺, and Cu^2- as compared with the other metal ions investigated. Especially, Fe³⁺ can lead to an almost complete fluorescence quenching of poly-mer P-1. Whereas, the analogous polymer P-2, in which Nethylcarbazole repeat units replace the fluorene units in P-1, shows a very poor selectivity, It demonstrates that polymers with a same receptor may show different sensitivity to analytes owing to their different type of backbones.