Donor-π-Acceptor Type Unsymmetrical Triarylborane-Based Fluorophores: Synthesis, Fluorescence Properties, and Photostability
Donor-π-Acceptor Type Unsymmetrical Triarylborane-Based Fluorophores: Synthesis, Fluorescence Properties, and Photostability
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DOI：
10.1021/acs.joc.8b01015
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发表时间：
2018-08-03
影响因子：
3.6
通讯作者：
Yamaguchi, Shigehiro
中科院分区：
文献类型：
--
作者：
Ito, Masato;Ito, Emi;Yamaguchi, Shigehiro
采用两步法合成了含三个不同芳基的三配位有机硼化合物。在第一次芳基取代为芳基硼酸酯发生后，中间体物质，即双（二芳基硼酸酯）物质，作为空气和水分稳定的固体被分离，这允许第二次芳基取代以选择性方式进行。随后，合成了一系列具有空间体积大的芳基、三芳胺和对位官能化苯环的不对称三芳基硼烷。这些三芳基硼烷不仅表现出显着的溶剂依赖性的荧光，如预期的供体它受体（D-pi-A）系统，他们也伴随着深刻的持久性对光照射，特别是对于那些轴承1，3，5-三叔丁基苯基环。研究结果表明，充分的电子和空间位阻修饰是构建光稳定的D-pi-A型三芳基硼烷荧光团的关键。
A two-step synthesis to prepare tricoordinate organoboron compounds bearing three different aryl groups has been developed. After the first aryl substitution to an aryl boronic ester took place, the intermediate species, that is, bis(diarylborinate) species, was isolated as an air- and moisture-stable solid, which allowed the second aryl substitution to carry out in a selective manner. Subsequently, a series of unsymmetrical triarylboranes possessing a sterically bulky aryl group, triarylamine moiety, and para-functionalized phenyl ring was synthesized. Not only did these triarylboranes exhibit remarkable solvent-dependent fluorescence as expected for donor it acceptor (D-pi-A) systems, they were also accompanied by profound persistence against photoirradiation especially for that bearing a 1,3,5-tri-tert-butylphenyl ring. This survey exemplifies that sufficient electronic and steric modification is key to construct photostable D-pi-A type triarylborane-based fluorophores.