作者:M. Hojo、M. Utaka、Z. Yoshida
DOI:10.1016/s0040-4020(01)91636-9
日期:1971.1
The effect of the Me2S+ group on the ionization of benzoic acid has been re-examined in comparison with that of the Me3N+ group. The thermodynamic pKa values of o-, m-, p-Me2S+ and o-, m-, p-Me3N+ substituted benzoic acids have been determined in 65 vol% aq. dimethyl sulfoxide, 50 vol% aq. ethanol, and in water potentiometrically. The result of this work, σp-Me2S+ ⪢ σm-Me2S+ is contrary to that previously
与Me 3 N +基团相比,已经重新检验了Me 2 S +基团对苯甲酸电离的影响。在65%(体积)的水溶液中测定了o-,m-,p -Me 2 S +和o-,m-,p -Me 3 N +取代的苯甲酸的热力学p K a值。二甲基亚砜,水溶液,体积百分比为50。乙醇和水中电位计。这项工作的结果,σp -Me 2 S + ⪢σ米-Me 2小号+是相反的,以前由他人,σ发现p -Me 2小号+ <σ米-Me 2小号+。发现以下关系而不管存在所使用的溶剂的:σ米-Me 2小号+ =σ米-Me 3 Ñ + + 0·06,和σ p -Me 2小号+ =σ p -Me 3 Ñ + + 0 Me 2 S +的共轭作用发现该基团从间位或对位增强酸,而从“邻位”变为弱酸。