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本文对三甲基乙烯在25℃和不同浓度的盐酸(0.1—2.5M),高氯酸(0.1—2.5M),硫酸(0.25—2.5M)水溶液中,进行反应速度的测定。结合在硝酸水溶液中(浓度0.1—4M)已测定的数据,求得下列表示速度的方程式: 盐酸 logk/C_(H_8O)+=(?).930+0.401C_(HCl) 高氯酸 logk/C_(H_8O)+(?).930+0.402C_(HClO_4) 硫酸 logk/C_(H_8O)+=(?).983+0.390C_(H_2SO_4) 硝酸 logk/C_(H_8O)+=(?).930+0.222C_(HNO_3) 在上列四种酸溶液中,三甲基乙烯的反应均为一级。如酸浓度以克当量计算,则四种酸催化速度的次序为:HClO_4(?)HCl>HNO_3>H_2SO_4。又在不同温度范围(15—42.5℃)及一定酸浓度下,测定反应的速度,以求算活化焓及活化熵值: △H~≠:HCl 22.1;HClO_4 21.5;H_2SO_4 21.4;HNO_3 22.5千卡/克分子△S~≠:HCl +0.9;HClO_4 —1.4;H_2SO_4 —13;HNO_3+1.3 e.u. 本文试用Hammett酸度函数H_0及Bunnett参数w来探讨反应机理,结果表明Zucker-Hammett假说及Bunnett方法对本反应的机理不能符合,Taft π-复合物机理亦有其矛盾之处。本文作者应用自由水的概念推导出的动力学公式为log k+H_0—m log C_(H_2O)=log k_0++log f_sf_(BH~+)/f_Bf_≠,并提出相应的反应机理。从(logk+H_0—mlog C_(H_2O))～C_酸图,又可说明在HCl,HClO_4,H_2SO_4水溶液中氢离子主要为四面体结构H_9O_+4~+,而在HNO_3水溶液中为泋离子H_3O~+形式。
In this paper, the reaction rate of trimethyl ethylene in 25 ℃ and different concentrations of hydrochloric acid (0.1-2.5M), perchloric acid (0.1-2.5M), sulfuric acid (0.25-2.5M) aqueous solution was measured. Combined with the measured data in an aqueous solution of nitric acid (at a concentration of 0.1 to 4 M), the following equation is expressed as a function of velocity: hydrochloric acid logk / C_ (H_8O) + = (?) 930 + 0.401C HCl perchloric acid logk / (H_8O) + (?) 930 + 0.402C_ (HClO_4) sulfuric acid logk / C_ (H_8O) + = (?) 983 +0.390C H_2SO_4 Nitric acid logk / C_ (H_8O) + = 0.222C_ (HNO_3) In the above four kinds of acid solution, the reaction of trimethyl ethylene is first class. If the acid concentration is calculated in terms of gram equivalents, the order of the four acid catalysis rates is: HClO_4 (?) HCl> HNO_3> H_2SO_4. The reaction rate was determined at different temperature ranges (15-42.5 ° C) and a certain acid concentration to calculate the enthalpy of activation and the entropy of activation: ΔH ~ ≠: HCl 22.1; HClO_4 21.5; H_2SO_4 21.4; HNO_3 22.5 kcal / Molecule △ S ~ ≠: HCl +0.9; HClO_4-1.4; H_2SO_4 -13; HNO_3 + 1.3 eu In this paper, Hammett acidity function H_0 and Bunnett parameter w to explore the reaction mechanism, the results show that the Zucker-Hammett hypothesis and the Bunnett method of the reaction The mechanism of Taft π-complex also has its contradictions. The kinetic formula derived from the concept of free water by the author is log k + H_0-m log C_ (H_2O) = log k_0 ++ log f_sf_ (BH ~ +) / f_Bf_ ≠, and the corresponding reaction mechanism is proposed. From the (logk + H_0-mlog C_ (H_2O)) ~ C_ acid diagram, it can be shown that the hydrogen ions in the HCl, HClO_4 and H_2SO_4 aqueous solutions are mainly tetrahedron structure H_9O_ + 4 ~ +, while in HNO_3 aqueous solution, H_3O ~ + form.