Two new dendronized nonlinear optical (NLO) polyfluorenes were synthesized with high azochromophore loading density by the introduction of high generation chromophore dendrons on the side chains. Thanks to the advantages of Sharpless' click chemistry reaction, the dendrons were conveniently bonded to the backbone of polyfluorene with the conversion of 100%, although they were really very bulky. The new-formed triazole rings in the dendrons acted as suitable isolation groups to minimize the strong dipole-dipole interactions among the polar chromophore moieties to improveNLO effects, according to the results obtained from UV-vis spectra and order parameters. All the polymers were well characterized and exhibited good solubility, high thermal ability, wide optical window, and largeNLOeffects (up to 106.0 pm/V). In addition, the testedNLOresults of these dendronzied polymers demonstrated a deviation from the dipolar frustration that typically limits the NLO effect in conventional chromophore/polymer composite materials, indicating that the frequently observed asymptotic dependence of electro-optic activity on chromophore density may be overcome through rational design.

By modifying the synthetic procedure, the previous reported impossible approach was successfully utilized to construct new azo-chromophore-containing hyperbranched polymers (HP1 and HP2) from AB2 monomers through click chemistry reactions with the aid of copper(I) catalysis. The two polymers were soluble in organic solvents and well characterized. Thanks to the advantages of the hyperbranched polymeric structure, the two polymers demonstrated good NLO properties, making them promising candidates for the practical applications.

To develop sensitive and selective CN-chemosensors, a new imidazole-functionalized polyfluorene (P1) was designed and obtained conveniently, the fluorescence of which could be completely quenched by Cu2+ ions at the concentration as low as 0.20 ppm in diluted solutions. By utilizing the much higher stability constant of the complex of CN-and Cu2+, the quenched fluorescence of the solution of P1 by Cu2+ ions could recover upon the addition of trace CN-anions, with the detection limit down to 0.31 ppm, making P1 a novel, sensitive and selective cyanide probe.

A novel series of indole-based conjugated oligomers were synthesized by Wittig-Horner-Emmons olefination from the aryl-bridged bisindole aldehydes and the corresponding bisphosphonates. The introduction of indole into the light-emitting materials made these oligmers exhibit favorable properties. They were thermally stable, and the UV-vis spectra of the oligomers could be modulated by the arylenevinylene units; their PL and EL spectra also showed similar properties that can be further modulated. The highest luminance achieved in a device with the configuration ITO/PEDOT:PSS/oligomer/Ba/Al was 2536 cd/m2 at 7.5 V for oligomer P6, and the highest external EL quantum efficiency of 0.39% and luminous efficiency of 0.97 cd/A were attained by oligomer P1.