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合成25个4,4’-二取代二苯乙烯化合物,测定了这些化合物在环己烷、乙醚、三氯甲烷、乙腈和醇等10多种溶剂中紫外吸收光谱的最大波长,共得到242个实验数据.讨论了取代基效应和溶剂效应对其紫外吸收光谱最大波长能量的影响.研究结果表明:同种溶剂中4,4′-二取代二苯乙烯化合物紫外吸收最大波长的能量主要受其分子内部结构(取代基效应)的影响,即由取代基的激发态参数σCexC和基态的极性参数σp共同决定;不同溶剂中其紫外吸收最大波长的能量由取代基效应和溶剂效应共同决定.提出了定量估算4,4′-二取代二苯乙烯化合物紫外吸收能量方程.并且发现,以溶剂在水/正辛醇中分配系数logP比用溶剂显色参数ET(30)度量溶剂效应更加有效,所得的定量方程相关性更好,物理意义更为明确.用所得方程对文献报道的有关化合物的紫外吸收光谱进行了预测,结果与实验测定值相吻合.
Twenty-five compounds of 4,4’-disubstituted stilbene were synthesized and the maximum wavelength of ultraviolet absorption spectra of these compounds in over 10 solvents such as cyclohexane, ether, chloroform, acetonitrile and alcohol was determined. A total of 242 The influence of substituent effect and solvent effect on the maximum wavelength energy of ultraviolet absorption spectrum is discussed.The results show that the energy of UV absorption maximum wavelength of 4,4’-disubstituted stilbene compound in the same solvent is mainly affected by The effect of the internal structure of the molecule (substituent effect) is determined by both the excited state parameter σCexC of the substituent and the polar parameter σp of the ground state. The energy of the maximum wavelength of ultraviolet absorption in different solvents is determined by both the substituent effect and the solvent effect. A quantitative estimate of the UV absorption energy equation for the 4,4’-disubstituted stilbene compound was proposed and it was found that it is more effective to partition the partition coefficient logP in water / n-octanol than to use the solvent color development parameter ET (30) to measure the solvent effect , The correlation of the quantitative equation obtained is better and the physical meaning is more clear.Using the equation to predict the UV absorption spectra of the related compounds reported in the literature, Value match.