Effects of substituent and solvent on the UV absorption energy of 4,4'-disubstituted stilbenes  

作　　者：CAO ChenZhong CHEN GuanFan WU YaXin 

机构地区：[1]Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education,Hunan Provincial University Key Laboratory of QSAR/QSPR,School of Chemistry and Chemical Engineering,Hunan University of Science and Technology,Xiangtan 411201,China

出　　处：《Science China Chemistry》2011年第11期1735-1744,共10页中国科学(化学英文版)

基　　金：financially supported by the National Natural Science Foundation of China (21072053 & 20772028) ;the Scientific Research Fund of Hunan Provincial Education Department (10K025)

摘　　要：Twenty five samples of 4,4'-disubstituted stilbene derivatives were synthesized, and their UV absorption max wavelengths were determined in over 10 kinds of solvents including cyclohexane, ether, chloroform, acetonitrile and ethanol, in which 242 experimental data were recorded. The effects of substituents and solvents on the energy of their UV absorption max wavelengths were discussed. The research results showed: the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was mainly affected by their intramolecular structure (substituent effect) in a given solvent, that is, the energy is dominated by both of excited-state substituent parameter o-~c and polar substituent constant crp. While their energy was dominated by the substituent effect and solvent effect in different kinds of solvents. An equation quantifying the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was developed. In addition, it is found that the n-octanol/water partition coefficient (logP) is more effective than the solvatochromic dye (ET(30)) in scaling the solvent effect. The equation employed the parameter logP has a better correlation and more specific physical meaning. Further, the energies of UV absorption max wavelengths of some reported compounds were predicted by the obtained equation, which are in agreement with their experimental values.Twenty five samples of 4,4'-disubstituted stilbene derivatives were synthesized, and their UV absorption max wavelengths were determined in over 10 kinds of solvents including cyclohexane, ether, chloroform, acetonitrile and ethanol, in which 242 experimental data were recorded. The effects of substituents and solvents on the energy of their UV absorption max wavelengths were discussed. The research results showed: the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was mainly affected by their intramolecular structure (substituent effect) in a given solvent, that is, the energy is dominated by both of excited-state substituent parameter ? CexC and polar substituent constant ?p. While their energy was dominated by the substituent effect and solvent effect in different kinds of solvents. An equation quanti- fying the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was developed. In addition, it is found that the n-octanol/water partition coefficient (logP) is more effective than the solvatochromic dye (ET(30)) in scaling the solvent effect. The equation employed the parameter logP has a better correlation and more specific physical meaning. Further, the energies of UV absorption max wavelengths of some reported compounds were predicted by the obtained equation, which are in agreement with their experimental values.

关 键 词：4 4'-disubstituted stilbene UV absorption energy excited-state substituent parameter solvent effect 

分 类 号：O621.25[理学—有机化学]