Diarylamino groups as photostable auxofluors in 2-benzoxazolylfluorene, 2,5-diphenyloxazoles, 1,3,5-hexatrienes, 1,4-distyrylbenzenes, and 2,7-distyrylfluorenes
Diarylamino groups as photostable auxofluors in 2-benzoxazolylfluorene, 2,5-diphenyloxazoles, 1,3,5-hexatrienes, 1,4-distyrylbenzenes, and 2,7-distyrylfluorenes
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DOI：
10.1021/jo020333
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发表时间：
2003-02-07
影响因子：
3.6
通讯作者：
Moyna, G
中科院分区：
文献类型：
--
作者：
Kauffman, JM;Moyna, G
在寻找最佳波长移位器中，确定了五种荧光剂的结构与光谱性质的关系，该波长移位器可用作加速器高能粒子检测系统的一部分。在寻找用作塑料纤维中的移波器的光稳定荧光剂的过程中，发现感兴趣的波长，吸收最大值410 +/-10 nm和荧光发射最大值480 20 nm，沿着其它性质，例如高溶解度和短荧光衰减时间，可以从由芳环和乙烯基组成的荧光体中仅通过使用氨基作为助色剂来获得波长的红移。由于伯，单烷基，和二烷基氨基没有足够的光稳定性，一些带有二芳基氨基的荧光团进行了研究。荧光素的合成利用了Buchwald胺化反应，这是Emmons-Horner反应的改进版本，以及其他常见的反应。氟的类型如下：2-苯并恶唑基-7-（4-二芳基氨基）芴7，2-（4-氰基苯基）-5-（4-氨基苯基）恶唑1,4和20，1，3，5-己三烯24 a-d和26 a-c，1，4-二苯乙烯基苯31 d-g和32 a-e，和2，7-二苯乙烯基芴40 a、d-e。不对称的荧光体7、14和20不如最好的己三烯、二苯乙烯基苯和二苯乙烯基芴那样明亮，它们都是对称的。在1，6-二芳基-1，3，5-己三烯24 a-d具有高荧光量子产率（Phi（f））的情况下，1，1，6，6-四芳基-1，3，5-己三烯26 a-c具有较低的c和Phi（f）。在1，4-二苯乙烯基苯31 d-g具有高Phi（f）的情况下，1，4-双（2-苯基苯乙烯基）苯32a-e具有Phi（f）= 0。二芳基氨基基团作为助荧光剂赋予更高的光化学稳定性比二烷基氨基类似的荧光团。1，4-二苯乙烯基苯31 d，e和2，7-二苯乙烯基芴40 d，e具有最理想的总体性能，包括2ns的快速衰减时间。计算机模拟相当好地预测了吸收和发射波长，但对预测亮度，稳定性，Phi（f）或衰变时间几乎没有帮助。
The relationship of structure to optical spectral properties was determined for five types of fluors in a search for an optimum-wavelength shifter to be used as part of the detection systems for high-energy particles from accelerators. In a search for photostable fluors to serve as waveshifters in plastic fibers it was found that the wavelengths of interest, absorption max 410 +/- 10 nm and fluorescence emission max 480 20 nm, along with other properties, such as high solubility and short fluorescence decay time, could be obtained from fluorophors composed of aromatic rings and vinyl groups only by using amino groups as auxochromes to give bathochromic shifts of wavelengths. Since primary, monoalkyl, and dialkylamino groups were not sufficiently photostable, a number of fluorophores bearing diarylamino groups were investigated. Syntheses of the fluors made use of the Buchwald amination, an improved version of the Emmons-Horner reaction, and other common reactions. The fluor types were the following: a 2-benzoxazolyl-7-(4-diarylamino)fluorene 7, 2-(4-cyanophenyl)-5-(4-aminophenyl)oxazoles 14 and 20, 1,3,5-hexatrienes 24a-d and 26a-c, 1,4-distyrylbenzenes 31d-g and 32a-e, and 2,7-distyrylfluorenes 40a,d-e. The unsymmetrical fluors 7, 14, and 20 were not as bright as the best hexatrienes, distyrylbenzenes, and distyrylfluorenes, which were all symmetrical. Where the 1,6-diaryl-1,3,5-hexatrienes 24a-d had high fluorescence quantum yield (Phi(f)), the 1,1,6,6-tetraryl-1,3,5-hexatrienes 26a-c had both lower c and Phi(f). Where the 1,4-distyrylbenzenes 31d-g had high Phi(f), the 1,4-bis(2-phenylstyryl)benzenes 32a-e had Phi(f) = 0. Diarylamino groups as auxofluors conferred higher photochemical stability than dialkylamino groups on similar fluorophores. The 1,4-distyrylbenzenes 31d,e and the 2,7-distyrylfluorenes 40d,e had the most desirable properties overall, which included fast decay times of 2 ns. Computer simulations predicted absorption and emission wavelengths fairly well, but were of little help for the prediction of brightness, stability, Phi(f), or decay time.