【作者】 王欢；

【导师】 郑炎松；

【作者基本信息】 华中科技大学 ， 有机化学， 2013， 硕士

【摘要】 分子开关作为化学分子的应用，激发了越来越广泛的兴趣，其中光致分子开关由于其分子种类多样、控制条件简便的优点得到了持续关注。腙类化合物在紫外光照和加热条件下可以产生顺反异构，在光致分子开关方面有一定应用潜能。本文合成了系列萘甲醛腙类化合物，对其紫外光、加热和超声处理诱导的异构性质进行了研究。（1）通过2-羟基/甲氧基-萘甲醛与羧酸酰肼的反应合成了5种腙类分子开关，利用¹H-NMR、¹³C-NMR、FT-IR等测试手段对其结构进行了表征。（2）这5种腙类衍生物在一般室温条件下为E型结构，利用紫外光照诱导发生E→Z异构，荧光强度发生大幅降低，最高达到77%。荧光强度变化的速度和幅度与分子结构存在紧密关系：易于生成分子内氢键，含有吸电子取代基，共轭性差的分子在紫外光照条件下荧光降低速度慢且幅度小。采用超声处理和加热方法诱导Z→E构型转变，荧光强度随之恢复，并且经交替的紫外光照和加热/超声处理后，荧光强度发生周期性循环变化。（3）结合1H-NMR、COSY以及荧光发射光谱证实异构化的发生，并推测和证明异构化前后分子构型分别为平面型和折叠型。通过比较不同化合物的光致异构化性质（光响应效率、荧光强度变化幅度等），挑选出性质最佳的化合物7e进行了更深入的系统探究：紫外光照不同时间后，核磁共振及荧光信号的变化；经紫外光照后，再进行不同时间的超声/加热处理，核磁共振及荧光信号的变化情况。实验结果表明化合物7e具有优异的光致异构化性能：对紫外光敏感、响应迅速，转化率高，异构体稳定性强，同时能够由加热及超声诱导发生Z→E异构化。特别是超声诱导的异构化响应速度快、转化率高，而利用超声波作为C=N异构化的响应条件也是第一次被发现和利用的。更多还原

【Abstract】 Molecular switch is an application of chemical molecule, which has aroused moreand more interests. Light induced molecular switch has been paid attention to persistently,because of its various species and simple control approaches. Hydrazone derivates haveE/Z isomerization induced by ultraviolet irradiation and heating and could be used asmolecular switch to some extent. A series of2-hydroxy/methoxy-naphthaldehyde-hydrazone derivates were synthesized, and isomerization characteristicsinduced by ultraviolet irradiation、heating and ultrasound approach were investigated.（1） Synthesized five2-hydroxy/methoxy-naphthaldehyde-hydrazone derivates, anddetected the molecular structures by¹H-NMR、¹³C-NMR、FT-IR.（2） These six hydrazone derivates possess E configuration in room temperature andcould convert to Z-isomer by ultraviolet irradiation. Fluorescence intensity decreased in theconversion process and it can decrease77%at most. The rate and ratio of decrease hadrelationship with the molecular structures: molecules with intramolecular H bond、electron-withdrawing groups and poor conjugation had worst conversion rate and ratio. TheZ-isomer could convert to E-isomer induced by heating and ultrasound approach and thefluorescence intensity recovered at the same time. Fluorescence intensity changedperiodically by interval ultraviolet irradiation、heating/ultrasound approach.（3） The isomerization was confirmed by the results of1H-NMR、 COSY andfluorescence spectra, and deduced the structures of these derivates before and after the useof inducing approach as planar and distortion. Made comparison of the series ofphotoisomerization characteristics and selected the best one7e to make further research:the changes of NMR and fluorescence spectra as a function of irradiation time orheating/ultrasound time after uv irradiation for30min. It showed that7e had outstandingisomerization characteristics: high reversing ratio、uv responding rate、 fluorescence intensity and stability，while Z→E isomerization can be induced by heating and ultrasoundapproach, and the latter was used to induce C=N double bond isomerization for the firsttime to our best knowledge.更多还原