硝基苯化合物对聚对苯撑乙炔基咔唑荧光淬灭性能研究

以2,5-二甲氧基对苯二乙炔和3,6-二碘-9-戊基咔唑为单体,采用Sonogashira偶合反应合成了含有咔唑基团的聚对苯撑乙炔基咔唑(P).硝基苯衍生物对该聚合物的荧光淬灭实验结果表明,当对位取代基团不同时,取代基的推电子能力越强对聚合物P的淬灭效率越高;对相同取代基的淬灭剂而言,邻、对位取代时的淬灭效率明显高于间位取代化合物.淬灭剂是与P通过形成电荷转移络合物而使处于激发态的P分子链发生能量转移的,淬灭剂对P荧光的淬灭效率随其浓度的增大而非线性升高.

Fluorescence Quenching Properties of Nitrobenzene Derivative toPoly

Poly(2,5-dipentyloxyphenylene ethynylene carbazyl)(P) was synthesized with 2,5-dimethoxy-1,4-diethynylbenzene and 3,6-diiodo-9-pentylcarbazole by Pd-catalyzed Sonogashira coupling reaction.The fluorescence quenched properties of P was influenced obviously by the structure and relative position of the substituting groups of nitrobenzene derivates.For the para-substituting nitrobenzene,the fluorescence quenching efficiency of quenchers increased with the increase of electron repulsion capability of the para-substituting group.And the fluorescence quenching efficiency reduced according to the sequence of o-NA,p-NA and m-NA under the same conditions due to the different electron withdrawing conjugated effect and inductive effect between amino-and nitro-group in nitroaniline isomers.Further study exhibits that the fluorescence quenching efficiency increases nonlinearly with the concentration of the quenchers.