中心Ga原子和周边取代基F原子对Corrole荧光性能的影响

The influences of central Ga atom and peripherally substituted F atoms on fluorescence properties of Corrole

采用稳态和时间分辨的光谱技术对比研究了Corrole大环中插入镓(Ga)原子及环周边取代基氟原子(F)数目的增多对Corrole荧光性能的影响.稳态吸收和荧光光谱表明:Corrole环中Ga原子的插入能增强Corrole的B带和Q带吸收,而周边修饰的拉电子取代基F的增多则减小Corrole的B带和Q带吸收.Ga原子的插入大大提高了Corrole的荧光量子产率;周边修饰的拉电子取代基F的增多亦能使Corrole的荧光量子产率有所提高.瞬态发光动力学测量结果表明:环中Ga原子的插入导致了Corrole更短的荧光寿命,周边修饰的拉电子取代基F的增多反而使得Corrole的荧光寿命稍变长.分析表明:在Corrole大环中插入Ga原子既大大提高了Corrole的荧光量子产率又缩短了其荧光寿命,使得相应的辐射跃迁几率提高了10倍左右;周边修饰的拉电子取代基F的增多提高了荧光量子产率且亦增长了Corrole荧光寿命,但最终使得辐射跃迁几率略微有所增加.

The fluorescence properties of four kinds of corroles are investigated by steady-state and transient spectroscopy, which were influenced by the insertion of gallium （Ga） atom into Corrole rings and the increasing of the number of peripherally substituted fluorine atom （F）. The steady-state absorption and fluorescence spectra show that the insertion of Ga atom can make the B and Q bands absorption of Corrole stronger while the increasing of peripherally substituented F atom weakens B and Q bands absorption. The insertion of Ga atom into corrole macrocyclic can greatly improve fluorescence quantum yield, and the same effect has been observed by increasing the number of the peripherally substituted F. The transient spectra show that the insertion of Ga atom can lead to shorter fluorescence lifetime, while the increasing of peripherally substituted F atom results in longer fluorescence lifetime. Therefore, the insertion of Ga atom into corrole macrocyclic can induce higher a 10 times larger radiative transition rate. On the other hand, the increasing of peripherally substituted F atom results in a slight increasinz in radiative transition rate.