Through space charge-transfer emission in lambda (Λ)-shaped triarylboranes and the use in fluorescent sensing for fluoride and cyanide ions
Through space charge-transfer emission in lambda (Λ)-shaped triarylboranes and the use in fluorescent sensing for fluoride and cyanide ions
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DOI：
10.1039/c5ra07912h
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发表时间：
2015-01-01
期刊：
影响因子：
3.9
通讯作者：
Hao, Yue
中科院分区：
文献类型：
--
作者：
Xi, He;Liu, Yang;Hao, Yue
设计并合成了一类新的lamda型三芳基硼烷2-(4-（N， N-二甲氨基）-8-基硼基-6H， 12h -5,11-甲二苯并[b， f][1,5]重氮辛（TBBN）和2-(4-（N， N-二苯氨基）-8-基硼基-6H， 12h -5,11-甲二苯并[b， f][1,5]重氮辛（TBBN2），它们通过刚性的lambda型Troger's碱连接剂结合了不同的供电子氨基和一个接受电子的基硼基。这些化合物显示出扭曲结构和有效的分子内变化转移转变。发色团的扭曲非平面排列一方面抑制了聚集态的荧光猝灭，另一方面产生了通过空间的给体-受体电荷转移。因此，观察到双荧光途径，即从氨基到二聚基硼基的空间电荷转移，以及位于氨基上的pi*-pi跃迁，在每个分子中共存。通过添加氟化物或氰化物离子，可以选择性地开启或关闭双重排放。因此，染料可以用作“开关”探针。TBBN和TBBN2与氟化物或氰化物离子的络合引起了显著的蓝移（约72-140 nm）和荧光颜色变化，使它们成为氟化物和氰化物离子的视觉比色和比例传感器。
A new class of Lambda-shaped triarylboranes 2-(4-(N, N-dimethylamino)-8-dimesitylboryl-6H, 12H-5,11-methanodibenzo [b, f][1,5] diazocine (TBBN) and 2-(4-(N, N-diphenylamino)-8-dimesitylboryl- 6H, 12H-5,11- methanodibenzo[b, f][1,5] diazocine (TBBN2), incorporating different electron-donating amino groups and an electron-accepting dimesitylboryl group through a rigid Lambda-shaped Troger's base linker were designed and synthesized. The compounds display twisted structures and effective intramolecular change-transfer transitions. The twisted nonplanar arrangement of the chromophores on the one hand suppresses the fluorescence quenching in the aggregated states, and on the other hand produces a through-space donor-acceptor charge transfer. As a result, dual fluorescent pathways, namely through-space charge transfer from the amino group to the dimesitylboryl group, and the pi*-pi transitions located on the amino groups, are observed to coexist in each molecule. The dual emissions can be selectively switched on or off by addition of fluoride or cyanide ions. Thus the dyes can be used as "switch-on" probes. The complexation of TBBN and TBBN2 with fluoride or cyanide ions induces dramatic blue shifts (about 72-140 nm) and color changes in the fluorescence, making them potential visually colorimetric and ratiometric sensors for fluoride and cyanide ions.