含手性碳偶氮苯化合物的合成及其光异构化反应

Synthesis and Photoisomerization of Azobenzene Compound Containing Chiral Carbon

以对氨基苯甲酸为原料,经重氮偶合、取代和酯化等一系列反应,合成一种新型含手性碳的偶氮苯化合物——4-(羧酸-2-甲基丁酯酯基)-(4'-辛氧基)偶氮苯(MBCO-Azo).利用红外光谱(FT-IR)和核磁共振氢谱(1H-NMR)对其结构进行了鉴定.通过紫外可见吸收光谱(UV-Vis)研究MBCO-Azo在甲醇溶液中的光异构化反应.结果表明:在360 nm紫外光照射下,MBCO-Azo发生由反式到顺式异构化反应,随后在440 nm可见光照射下发生由顺式到反式异构化反应.在光异构化中MBCO-Azo最大吸收波长变化较宽,可达到24 nm.由于手性单元的引入,MBCO-Azo由反式到顺式的光异构化速率略大于4-(羧基)-(4'-辛氧基)偶氮苯(CO-Azo),而顺式到反式的回复速率则略小.

A novel azobenzene compound containing chiral carbon,4-（2-methyl butylcarboxylate）-（4′-octyloxy）azobenzene（MBCO-Azo）was synthesized by diazo coupling,substitution and esterification reaction.The structures of compounds were characterized by FT-IR and 1H-NMR.The photoisomerization of MBCO-Azo was investigated using UV-Vis spectroscopy.The results indicate that MBCO-Azo in MeOH can undergo trans→cis isomerization irradiated with 360 nm UV-light,and cis→trans isomerization irradiated subsequently with 440 nm visible light.The change of the maximum absorption wavelength of MBCO-Azo became widely.The ratio of trans→cis isomerization of MBCO-Azo was slightly faster than that of 4-（carboxy）-（4′-octyloxy）azobenzene（CO-Azo）,while the ratio of cis→trans isomerization of MBCO-Azo was slight slower than that of CO-Azo due to the introduction of chiral carbon.