Triptycene Based Fluorescent Polymers with Pendant Alkyl Chains: Interaction with Fullerene and Morphology of Thin Films

摘要： We report unique triptycene based alternating copolymers bearing long alkyl chains as pendants. Syntheses utilized 2,6-diethynyltriptycene and appropriate alkyloxyarene monomers polymerized via Sonogashira cross coupling reaction to yield triptycene based poly(phenylene ethynylene)s (TPPEs). Resulting polymers are soluble in organic solvents and were characterized by FT-IR, NMR, GPC, TGA, AFM, SEM, UV-visible and fluorescence spectroscopic techniques. Experimental results suggest polymers are thermally stable and fluorescent. The fluorescence emission was quenched in presence of fullerenes (C60 and C70) suggesting their strong host-guest interactions. The magnitude of binding constant between polymer and these fullerenes was determined to be in the order of 105 M-1.The effect of chain length on the morphology and wettability of polymers on silicon substrates were studied using atomic force microscope. Three distinct dewetting patterns viz., spherical domains, fractal and ring structures, were observed with variation in the pendant chain length. This ability to control the thin film morphology of polymers may have potential technological applications, which includes but is not limited to sensors, fluorescent coatings and organic electronics.