沉淀剂对含有氨侧基的聚苯撑乙炔发光性能的影响

Effect of Precipitant on the Luminescent Property of Poly(phenylene ethynylene) with p-Aminophenyl-ethynyl as Side-group

通过单体4-[(2,5-二溴苯)乙炔基]苯胺和1,4-二乙炔基-2,5-二戊氧基苯之间的Sonogashira偶合反应合成了带有p-氨基苯乙炔基共轭侧基的聚对苯撑乙炔(PAnPE).该共轭聚合物的THF溶液(2×10-5mol·L-1)在473和519nm处呈现两个比较强的荧光发射峰.通过调节在聚合物PAnPE-THF溶液中所加入三种沉淀剂(甲醇、乙酸、稀盐酸溶液)的体积比例,来改变PAnPE分子链的聚集态结构,进而研究对其发光性能的影响规律.实验结果表明:由于沉淀剂与聚合物PAnPE分子链之间相互作用能力与方式的不同,PAnPE两个荧光峰的发射强度因聚合物分子链聚集结构不同而呈现不同的变化规律,这有助于实现在化学传感器中的应用.

The poly（phenylene ethynylene） （PAnPE） with p-aminophenyl-ethynyl as a side-group was synthesized through Pd-catalyzed Sonogashira coupling reaction between 4-[（2,5-dibromophenyl）ethynyl] aniline and 1,4-diethynyl-2,5-bis（pentyloxy） benzene. In THF solution, PAnPE exhibits two strong fluorescence emission peaks at 473 and 519 nm. The fluorescence properties of PAnPE are discussed when adjusting the kind and content of the precipitants, including methanol, acetic acid and dilute hydrochloric acid, which can influence the aggregation state of PAnPE. The experimental results exhibit that the intensity of the two fluorescence peaks of PAnPE display different downtrend due to the different aggregating structure of polymer molecular chain in mixed solvents which was ascribed to the different potency and type of the interaction between the precipitants molecules and PAnPE molecular chains. These results are helpful to achieve its application in chemo-sensors.