具有聚集诱导发光性能的并吡咯衍生物的多晶性和酸响应行为研究

Properties of Polymorphism and Acid Response of Pyrrolopyrrole-based Derivative with Aggregation-induced Emission Behavior

本工作合成了具有A-D-A结构的并吡咯衍生物4',4''-(2,5-二苯基吡咯并[3,2-b]吡咯-1,4-二基)双([1,1'-联苯]-4-腈)(DPPDC),该化合物具有聚集诱导发光(AIE)特性,在四氢呋喃/水体系中,当水含量为99%(体积含量)时,DPPDC的荧光强度比在纯四氢呋喃体系中增强了11倍.通过不良溶剂缓慢扩散到溶液体系的方法,培养得到四种DPPDC单晶,体现出DPPDC具有良好的多晶性.四种晶体发光颜色各不相同,分别为蓝色、天蓝色、青绿色和绿色,波长变化范围为29 nm.此外由于并吡咯结构富含电子特性,它能与三氟乙酸相互作用,从而影响其荧光发射,发光颜色从黄色变为橙红色,故该化合物可作为酸响应的荧光检测试剂.

A new A-D-A type pyrrolopyrrole-based derivative 4＇,4″-（2,5-diphenyl-pyrrolo[3,2-b]pyrrole-l,4-diyl）bis （[ 1, 1＇-biphenyl]-4-carbonitrile） （DPPDC） was synthesized via Suzuki coupling reaction between 1,4-bis（4-bromophenyl）-2,5-diphenyl-1,4-dihydropyrrolo[3,2-b]pyrrole and 4-cyanophenylboronic acid. The fluorescent emission intensities of DPPDC in pure THF solution and lower fraction of water （~H20~〈 60%） mixtures were weak at around 550 nm. When ~H2O was 99% in THF/H20 mixtures, the emission was enhanced and blue-shifted at around 505 nm. The maximal fluorescent emission intensity of DPPDC was 11 times higher than that of in pure THF solution, indicating DPPDC exhibiting AlE property. It was also found that four different kinds of crystal structures of DPPDC was cultivated from CHC12-Hexane, CHC13-Hexane and CHC13/Acetone-Hexane systems via solvent slow diffusion method. Four crystals respec- tively emitted blue, azure, green and turquoise at 467, 483,496 and 493 nm, which manifested the polymorphism-dependent fluorescent emission property of DPPDC. Additionally, trifluoroacetic acid （TFA） could make the emitting color change from yellow to orange-red with as-prepared paper containing DPPDC due to the acid-base interaction. The obvious emitting color change of DPPDC can be used as a visual sensor to detect acid gas.