类杯芳烃孔穴桥联双芘分子开关化合物

Bridged Di-py-cavitand Compounds as Molecular Switch

利用构型可变的分子开关类杯芳烃孔穴化合物(Cavitand)作为母体,合成了2种具有不同臂长的双芘Cavitand化合物.在室温及中性状态下,2种双芘Cavitand化合物均可检验出分子内激基复合物荧光,其中短臂双芘Cavitand化合物的荧光明显强于长臂Cavitand化合物.经三氟乙酸酸化后,2种双芘化合物的分子内激基复合物荧光消失;而继续使用碱中和至中性,则荧光恢复.这个荧光出现-消失-出现的过程验证了Cavitand母体化合物分子构型闭合-打开-闭合可有效调控分子激基复合物荧光开关过程.此外,通过高斯计算模拟了2种化合物的理论分子构型,发现长臂双芘化合物在Cavitand母体构型处于闭合状态时2个芘基团重叠部分较少是其分子内激基复合物荧光较弱的关键原因.

Two kinds of di-py-cavitand compounds with different arm lengths were synthesized using molecular switch which configurations are variable-class calixarene cavities（Cavitand） as the parent compounds. In the neutral state of room temperature, the two kinds of di-py-cavitand compounds can detect intramoleeular exei- plex fluorescence and the compounds with short arm is obviously more stronger than the long arm one in the fluorescence intensity. However, intramolecular exciplex fluorescence disappears after acidification by trifluoroacetic acid and appears again when continuing to add alkali so as to neutralize to neutral state. The process of fluorescence appearing-disappearing-appearing powerfully verified that the process of closing- opening-closing of the molecular configuration of eavitand parent compounds can efficiently control intramolecular exciplex fluorescence＇ s opening and closing processes. In addition, the molecular configura- tions of di-py-eavitand compounds in theory with different arm length were simulated through Gaussian calcula- tion module, finding that two pyrene groups of di-py-cavitand compound with long arm were less overlaped when the cavitand parent configuration was in the closing state, which is the key cause of the corresponding weak intramolecular exeiplex fluorescence intensity.