New bead type and high symmetrical diallyl-POSS based emissive conjugated polyfluorene

A new bead type and diallyl-POSS based polyfluorene (P2) with high symmetrical structure was synthesized via Heck coupling reaction between oligomeric alkynyl fluorene (P1) and diallyl polyhedral oligomeric silsesquioxanes (diallyl-POSS). The molecular weight and the conjugated length of P1 and P2 were well controlled to acquire good solubility and excellent optical property. The bead-type POSS based polymer was characterized by gel permeation chromatography (GPC), FT-IR, 1H NMR and photoluminescence (PL) spectra. High Resolution Transmission Electron Microscopy (HRTEM) micrographs showed that diallyl-POSS were uniformly nano-dispersed in the polymer matrix. Compared with P1, the POSS based polyfluorene P2 exhibited not only a higher thermal stability, but also an improved photophysical property in solution and solid states. The incorporation of diallyl-POSS resulted effectively in inhibiting the strong stacking/dipole-dipole interaction between fluorescent groups in the polyfluorene. The experimental results indicate that the bi-functional POSS based light-emitting polymers with high symmetrical structure can have great potential in optical materials and devices, such as OPV or PLED, etc.

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