具有聚集诱导发光特性的磷光聚合物的合成及性能研究

Synthesis and Properties of Phosphorescent Polymers with Aggregation-induced Emission

通过钯催化的Suzuki偶联反应将四苯基乙烯单元、铱配合物及9,9-二辛基芴单元共聚,得到了一系列具有聚集诱导发光(AIE)特性的磷光聚合物.通过改变铱配合物在聚合物中的含量,研究了聚合物的热稳定性、光物理性能以及聚集诱导发光特性.聚合物具有良好的热稳定性,热分解温度(T_d)都在300°C以上,玻璃化转变温度(T_g)在100°C左右.改变聚合物中铱配合物的浓度,磷光聚合物的发射峰位置基本保持不变,最大发射峰在505 nm左右.在THF/水的混合溶剂中,随着水含量从0%增加到90%,磷光聚合物的荧光强度和量子效率都表现出先增大后减小的趋势,说明磷光聚合物具有聚集诱导发光(AIE)特性,是非典型的AIE材料.

A series of phosphorescent polymers with aggregation-induced emission(AIE)feature were synthesized by palladium-catalyzed Suzuki polycondensation of tetraphenylethene(TPE),iridium complex and 9,9-dioctylfluorene.All the obtained polymers are soluble in common organic solvents,such as chloroform,dichloromethane and tetrahydrofuran(THF),at room temperature,but insoluble in water.Their thermal and photophysical properties,as well as AIE performance of the resulting phosphorescent polymers are investigated with different feed ratios of iridium complex varing from 0.5%to 4%.These polymers display good thermal properties with a high thermal degradation temperature(>300℃)and glass transition temperature(≈100℃).Polymer PFTPE displays the maximum photoluminescent(PL)emission at 440 nm.Relative to PFTPE,all the phosphorescent polymers prepared with iridium complex feed ratios in the range of 0.5%.4%emit green light with an emission peak at about 505 nm.AIE performances of these phosphorescent polymers are examined by studying the PL emission behaviour of their diluted mixture in THF/water under different water fractions(fw).The aggregates are prepared by adding different fractions(fw=0%to 90%)of ultra-pure water into THF solution.Both PL intensity and quantum yield(ФPL)of PFTPE-Fir0.5 and PFTPE-Fir1 exhibit an upward trend with the increasing fw from 0%to 80%.However,when fw further increases from 80%to 90%,PL intensity andФPL show downward trend.The maximum values ofФPL are 37.3%for PFTPE-FIr0.5 and 38.6%for PFTPE-FIr1,respectively.Similarly,PL intensity andФPL of PFTPE-FIr2 and PFTPE-FIr4 display the same behaviour as PFTPE-FIr0.5 and PFTPE-FIr1.And PFTPE-FIr2 and PFTPE-FIr4 reach the maximumФPL value of 37.2%and 39.9%,respectively,at fw of 30%.This indicates that these phosphorescent polymers have AIE feature,suggesting that they are potential materials for fabrication of organic light-emitting diodes and fluorescent sensors.