中文摘要：

用Knoevenagel方法，合成了MEH-CN—PPV，通过对其^1H-核磁共振（^1H-NMR）谱的研究，在MEH-CN-PPV的^1H-NMR谱中发现烯键的Z／E两种构型的信号，通过积分面积初步估算E构型占15％，Z构型占85％。并且合成了模型化合物——齐聚物（E，E）-1，4-二（1-氰基-2-苯乙烯基）-2-（2-乙基己氧基）-5-甲氧基苯，其发生异构时，^1H-NMR谱的变化与MEH—CN—PPV的Z／E两种构型在^1H-NMR谱中的信号吻合。

英文摘要：

CN-PPV is one of the important series of PPV and its derivatives, demonstrating very high quantum efficiency of over 4% in a two-layers device, ITO/PPV/CN-PPV/Al. It is widely known that the defects in thepolymer backbone can affect the properties of the device. The main structural defects in PPV-type polymers involve the ＂tetrahedral＂ structural segments and the E-double bone configurations. conjugated In order to achieve a better understanding to the structure of MEH-CN-PPV, the model compound （8a） （Z,Z-confignration） was synthesized. The Z/E-isomerization of the vinylene moiety with cyano group happened easily under the influence of visible and UV light. （8a） dissolved in chloroform was irradiated in daylight for 2 days under purging nitrogen. Its NMR spectrum become more complex, which showed the occurrence of the Z/E-isomerization. Through a careful separation for this mixture by column chromatography （silica gel, cyclohexane/ dichloromethane 2：5） in the dark, two new compounds （8b） （a green solid） and （8c） （yellow oil） were obtained. According to the ^1H-NMR spectra, the configuration of （8b） was E,E and that of （8c） was Z,E. In the ^1H-NMR spectrum of the copolymer MEH-CN-PPV, the main signals were similar to （8a）, which indicated that the configuration of the copolymer MEH-CN-PPV was mainly Z. Some feeble signals at 6.47×10^-6 and 3.32×10^-6 were similar to the signals of the protons on the vinylene bond and OCH related with the Econfigu＇ration in （8b） and （8c）. Hence these signals can prove the presence of the E-configuration in MEHCN-PPV backbone. The ratio between the signal （d） and the signal （a） was 0.09. The contents of the Z/Econfiguration could be estimated： for Z-configration was 85% and 15% for E-configration.