Outlaw Victor K, Zhou Jiawang, Bragg Arthur E, Townsend Craig A
Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
Department of Chemistry, The Johns Hopkins University, Remsen Hall, 3400 N. Charles Street, Baltimore, MD 21218, USA.
RSC Adv. 2016 Jul 8;6(66):61249-61253. doi: 10.1039/C6RA10605F. Epub 2016 Jun 3.
6-Amino-8-cyanobenzo[1, 2-]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.
6-氨基-8-氰基苯并[1,2-]中氮茚，一类新型的光致发光材料，表现出可逆的pH依赖光学性质，其特征是质子化时荧光发射出现罕见且显著的蓝移。酸滴定和核磁共振光谱实验表明，观察到的光物理变化并非预期的N-质子化，而是C-质子化和芳香性的丧失所致。由吲哚-2-甲醛进行的高效合成使得该核心的各种取代版本易于获得，以调节光学和pH效应。
