Tunable fluorescence conjugated copolymers consisting of tetraphenylethylene and fluorene units: From aggregation‐induced emission enhancement to dual‐channel fluorescence response

Abstract

A series of new conjugated polymers PTPExFy, which consist of tetraphenylethylene (TPE) units and fluorene (F) units, have been designed and synthesized by Suzuki cross‐coupling polymerization. The polymers PTPExFy exhibited aggregation‐induced emission enhancement and dual‐channel fluorescence response (DCFR) when they were aggregated in solution, and these properties are related with their TPE‐to‐F ratio in the polymer backbone. For PTPE and PTPE0.5F0.5, the fluorescence emission was enhanced by aggregation when water was added into their THF solutions. For the copolymers PTPE0.3F0.7, PTPE0.2F0.8, and PTPE0.1F0.9, the DCFRs were observed when they were aggregated by adding water into their solution, which can be attributed to the different responses of fluorene segments and TPE segments to aggregation. The fluorene segments have an aggregation‐caused quenching characteristic, whereas the TPE segments have an aggregation‐induced emission characteristic. According to the fluorescence lifetime and quantum yield data of the polymer solutions, we have discovered that the polymer's natural life time increases as its TPE content increases. In the solid film, PTPE0.3F0.7 and PTPE0.2F0.8 showed better quantum yield than other polymers, due to the combination of the excellent fluorescent property of the fluorene groups and the nonplanar conformation of the TPE groups. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

White light emitting single polymer from aggregation enhanced emission: a strategy through supramolecular assembly

“…The above results are well 50 comparable with the reported polymeric AIEE system. 64 In contrast to the white light emission from the thin film state where as the solution state showed blue emission for FC 2.5. The above emission effects can be attributed to low percentage composition of FCP monomer in FCP 2.5 copolymer.…”

Diphenylphosphoryl‐Triazole‐Tethered, AIEE‐Type Conjugated Polymer as Optical Probe for Silver Ion in Relatively High‐Water‐Fraction Medium

“…Alterations of PL spectra can be clearly observed with the increase of water fraction, that is, the general tendency of increase at ≈ 500 nm and decrease at ≈ 420 nm, suggesting the energy transfer from high-energy fl uorene-carbazole band to relatively low-energy fl uorene-TPE segment. [ 29,38,39 ] The emission intensity in THF/H 2 O = 1:9 is ≈ 4.2-folds higher than that in pure THF; this is a typical refl ection of AIEE effect. Since water is nonsolvent for P3 , the changes of P3 's fl uorescence intensity can be assigned to the formation of intermolecular aggregate between polymer chains in solvent mixtures with high water contents, thus activating AIEE effect by restricting intramolecular rotation of TPE and blocking its nonradiative pathways.…”

“…Emission of P3 peaks at ≈420 nm in pure THF, which can be assigned to the emission of fl uorene-carbazole conjugated segments. Another emission band at ≈ 500 nm, which origins from the emission of fl uorene-TPE segments, [ 29,38,39 ] appears when the water faction ratio exceeds 10% in mixing solvents. Alterations of PL spectra can be clearly observed with the increase of water fraction, that is, the general tendency of increase at ≈ 500 nm and decrease at ≈ 420 nm, suggesting the energy transfer from high-energy fl uorene-carbazole band to relatively low-energy fl uorene-TPE segment.…”

The Impact of Aggregation on the Photophysics of Spiro‐Bridged Heterotriangulenes

“…[21] In aggregates of FTP and FTPO, in which numerous fluorene-fluorene contacts are present, fluorescence from the fluorenes is suppressed similarly to previous experimental findings for polymers comprising fluorene moieties. [54] Information about the nature of the aggregates in the dispersions was gathered by means of dynamic and static light scattering (DLS and SLS). We recorded the static scattering intensity of the samples,ameasure for the number and size of particles,a safunction of the water content ( Figure 6, black dots).…”