烷基链长对四苯基乙烯衍生物聚集行为和光学性质的影响

摘要

Two tetraphenylethene derivatives, i.e.1,1,2,2-tetra(4-(hexyloxy)phenyl)ethene (THPE) and 1,1,2,2-tetrakis(4-(decyloxy) phenyl)ethene (TDPE) containing alkyl chains with different lengths were prepared.The optical properties of THPE and TDPE in THF/water mixtures with different water contents were investigated by UV-Vis and fluorescence spectroscopy.The structures of the aggregates of THPE and TDPE formed in THF/water mixtures were observed by SEM.Level-off tails in the UV-Vis spectra of THPE and TDPE in THF/water mixtures can be seen as water contents reach the critical points.However, the critical points for the two derivatives differ, as level-off tails were seen in the UV-Vis spectra of THPE and TDPE when water contents reached 50% and 40%, respectively.THPE and TDPE both are AIE active and their fluorescence quantum yields increase with the increasing of water contents.However, the initial points of the rapid growth of their fluorescence quantum yields are different.The fluorescence quantum yields of THPE and TDPE began to quickly increase when their water contents reached 40% and 30%, respectively.THPE and TDPE both can self-assemble into ordered aggregates.THPE can self-assemble into ordered nanorods under 70% water content, and TDPE can self-assemble into ordered nanorods and microplates under only 50% water content.These data indicate that TDPE with longer alkyl chains can aggregate more easily.New AIE materials with high fluorescence quantum yields and structure-controlled aggregates can be expected to be prepared by tuning the lengths of alkyl chains.%制备了带有不同烷基链长的四苯基乙烯衍生物1,1,2,2-四(4-正己氧基苯基)乙烯(THPE)和1,1,2,2-四(4-正癸氧基苯基)乙烯(TDPE),并采用紫外吸收光谱、荧光光谱研究THPE和TDPE在四氢呋喃(THF)/H2O混合溶剂中的光物理性质,通过扫描电镜观察THPE和TDPE在THF/H2O中形成的聚集体的形态结构.结果表明,THPE和TDPE在THF/H2O中的紫外吸收光谱都出现拖尾现象,然而开始出现拖尾时溶剂中的水含量不同,THPE和TDPE分别在水含量为50%和40%的THF/H2O中开始出现拖尾现象;THPE和TDPE都具有聚集诱导发光(AIE)性能,它们的荧光量子产率随着水含量的增加而增大,但是荧光量子产率快速增长的起始点不同,THPE和TDPE的荧光量子产率分别在水含量达到40%和30%后开始快速增长;THPE和TDPE在THF/H2O中都能形成形状规则的聚集体,不同的是THPE在水含量为70%时才形成有序的纳米棒,而TDPE则在水含量为50%时即能形成纳米棒和微米片.这表明,带有长烷基链的TDPE更容易聚集,通过调节烷基链长度,有望制备出发光效率高、聚集体结构可控的AIE材料.