SYNTHESIS AND SOLUTION PHOTOPHYSICS PROPERTIES OF A meta-LINKED ANIONIC POLY(PYRIDINYLENE ETHYNYLENE) CONJUGATED POLYELECTROLYTE
间位聚亚吡啶基亚乙炔基共轭聚电解质的合成与溶液光物理性质

The monomer 1,4-diiodo-2,5-di(propyloxysulfonate)benzene and 2,6-diethynylpyridine were synthesized and a meta-linked anionic poly(pyridinylene ethynylene) conjugated polyelectrolyte m-PPYPE-SO3Na was synthesized via Pd-catalyzed Heck-Sonogashira coupling reaction.Monomers and the polymer were characterized by Fourier transformed infrared spectroscopy and proton nuclear magnetic resonance spectroscopy.The conjugated polyelectrolyte m-PPYPE-SO3Na was characterized by UV-Vis and photoluminescence spectroscopy and the solution photophysics properties of the polymer were investigated.The fluorescence spectra of the conjugated polyelectrolyte in different solvent and under different polymer concentrations showed concentration- and solvent-dependency of the conjugated polyelectrolyte,respectively,which could be attributed to the aggregation of the conjugated polyelectrolyte in water solution.The emission peak of the aggregation disappeared approximately when the concentration of the polymer was about 1×10-6 mol/L,and this fact shows that the extent of the polymer aggregation was very low.It was found that surfactant affected the aggregation of the polyelectrolyte.The introduction of polymer-type surfactant poly(vinyl pyrrolidone) (PVP) into the water solution of m-PPYPE-SO3Na increased the fluorescence intensity of the polymer solution.The interaction of PVP with m-PPYPE-SO3Na in aqueous solution broke the aggregation of the conjugated polyelectrolyte.The solution photophysics properties suggests that the conjugated polyelectrolyte has potential to be a kind of water soluble fluorescence probe.