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红外光谱中溶剂效应机理研究(Ⅳ) 溶剂受电子位阻效应常数的确定
Study on the Mechanism of the Solvent Effect of Infrared Spectra (Ⅳ)Determination of the Constants of Electron Acception Space Effect of Solvents
【Abstract】 In the previous paper(Ⅲ), the following equation of solvent effect in organic chemistry was suggested:Where Ei is a physical or chemical property of the substrate in the solvent i and E0 is that in n-hexane. Ai and Di are constants of electron acception and donation effect of the solvent i respectively. VAi and VDi are constants of electron acception and donation space effect of the solvent i respectively, a and d are the sensitivities of E of the substrate vs the change of Ai and Di. Va and Vd are the constants of electron acception and donation space effect of the substrate respectively. In IR spectra E couJd be substituted by the wavenumber (v). Ai and VAi have been estalished for 18 organic solvents (n-C6H14, n-C7H16, cyclohexane, CC14, Ph-Me, ClCH:CCl2, Et2O, CHCl3, C6H6, CH2Cl2,ClCH2 CH2Cl, Ph-NO2, THF, 1,4-dioxane, Et-NO2. MeCO2Et, Me-NO2, Me-CN).In this paper Di and VDi have been established for these solvents. The equation also has been tested by the vC-X (X=Cl, Br) of five alkylhalides (t-BuCl, ) n-C5H11Cl,t-BuBr, Et-Br, EtC(H)BrMe) and YC=O of three carboxyl compounds (t-BuCOMe,Me2CO, MHB) and seven organotin compounds [(Ph2MeSiCH2)3SnO2C-C6H4-X-p (X=H-, CH3-, CH3O-, NO2-, F-, Cl-, I-)].The relationship (u = ρ·σ + vo) between vC=O of organotin compounds and Hammett constants (σ) of the substituted groups in different solvents was studied and a relationship bewteen ρ and Ai, VAi ) Di, VDi of the slovents was found.
【Key words】 Solvent effect; Ralationship analysis; Infrared spectra; Hammett equation;
- 【文献出处】 物理化学学报 ,Acta Physico-chimica Sinica , 编辑部邮箱 ,1995年09期
- 【分类号】O621
- 【被引频次】2
- 【下载频次】117