Synthesis and isomerization of conjugated oligomers containing azoimidazole unit
Synthesis and isomerization of conjugated oligomers containing azoimidazole unit
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含偶氮咪唑单元的共轭低聚物的合成与异构化
DOI：
10.1002/pola.24958
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
T. Seki
中科院分区：
文献类型：
--
作者：
Koji Takagi;T. Isomura;Yohei Ito;Masanori Sakaida;Shusaku Nagano;T. Seki
Suzuki （O1-O3）和Stille （O4）偶联聚合得到在1位上有苯基保护基团的2-（苯偶氮）咪唑偶联低聚物。由2,5-二烷基-1,4-苯基交替组成的共轭低聚物O2中的中性咪唑转化为阳离子咪唑盐O2S。根据偶联伙伴的化学结构，共轭低聚物的吸收最大值与模型化合物M的4,5位苯环的吸收最大值有红移或蓝移。阳离子共轭低聚物O2S的最大吸收波长较中性共轭低聚物O2有蓝移。在436 nm的光照射下，观察了偶氮咪唑在共轭低聚物中的反式到顺式的光异构化过程，顺式结构的转化程度与材料的最大吸收波长大致相关。膜态的反-顺光异构反应缓慢。另一方面，证实了偶氮咪唑单元的顺反热异构化，吸光度恢复到光异构化前的初始状态。阳离子共轭低聚物O2S的反-顺光异构化需要较大的能量，长时间的光照射会使偶氮咪唑单元分解。©2011 Wiley期刊公司高分子材料学报，2011。
The Suzuki (for O1–O3) and Stille (for O4) coupling polymerization of 2-(phenylazo)imidazole bearing the benzyl protecting group at the 1-position gave conjugated oligomers. The transformation from the neutral imidazole in the conjugated oligomer O2, consisted of the alternating 2,5-didecyl-1,4-phenylene unit, to the cationic imidazolium salt O2S was performed. Depending on the chemical structure of coupling partners, the absorption maximum of conjugated oligomers showed red shift or blue shift from that of the model compound M with the benzene ring at the 4,5-positions. The absorption maximum wavelength of the cationic conjugated oligomer O2S showed a blue shift from that of the neutral conjugated oligomer O2. The trans-to-cis photoisomerization of the azoimidazole unit in conjugated oligomers was observed by irradiating the light at 436 nm, and the conversion degree to the cis structure had a rough correlation with the maximum absorption wavelength of materials. The trans-to-cis photoisomerization in the film state was sluggish. On the other hand, the cis-to-trans thermal isomerization of the azoimidazole unit was confirmed and the absorbance returned to the initial state before the photoisomerization. The trans-to-cis photoisomerization of the cationic conjugated oligomer O2S required large energy, and the prolonged light irradiation might decompose the azoimidazole unit. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.
合成含有外二氟亚甲基部分的脱氧糖二核苷酸，作为研究异常糖生物合成中涉及的酶的机制探针。
DOI：
10.1021/jo0103672
发表时间：
2001
期刊：
The Journal of organic chemistry
影响因子：
--
作者：
Zhao,Z;Liu,H
通讯作者：
Liu,H