Unusual Blue-Shifted Acid-Responsive Photoluminescence Behavior in 6-Amino-8-cyanobenzo[1,2-b]indolizines.
Unusual Blue-Shifted Acid-Responsive Photoluminescence Behavior in 6-Amino-8-cyanobenzo[1,2-b]indolizines.
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DOI：
10.1039/c6ra10605f
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发表时间：
2016-07-08
期刊：
影响因子：
3.9
通讯作者：
Townsend CA
中科院分区：
文献类型：
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作者：
Outlaw VK;Zhou J;Bragg AE;Townsend CA
6-氨基-8-氰苯并[1,2 -b]吲哚嗪是一类新型的光致发光材料，具有可逆的ph依赖光学性质，其特征是质子化时荧光发射出现罕见的显著蓝移。酸滴定和核磁共振光谱实验表明，与预期的n -质子化相反，c -质子化和芳香性的丧失是导致观察到的光物理变化的原因。吲哚-2-羧醛的高效合成使得该核的各种取代版本易于调节光学和pH效应。
6-Amino-8-cyanobenzo[1, 2-b]indolizines, a new class of photoluminescent materials, exhibit reversible pH-dependent optical properties characterized by an uncommon and dramatic blue shift in fluorescence emission when protonated. Acid titration and NMR spectroscopy experiments reveal that, rather than the anticipated N-protonation, C-protonation and loss of aromaticity is responsible for the observed photophysical changes. Efficient synthesis from indole-2-carboxaldehydes makes variously substituted versions of this nucleus readily available to tune optical and pH effects.