Correlation of the Rates on Solvolysis of 2,2,2-Trichloroethyl Chloroformate Using the Extended Grunwald-Winstein Equation

Bulletin of the Korean chemical society

Han Joong Koh¹  Suk Jin Kang¹ 

关键词: 2;    2;    2-Trichloroethyl chloroformate;    Extended grunwald-winstein equation;    SN2 Mechanism;    Solvent kinetic isotope effect;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

The solvolysis rate constants of 2,2,2-trichloroethyl chloroformate (Cl3CCH2OCOCl, 3) in 30 different solvents are well correlated with the extended Grunwald-Winstein equation, using the NT solvent nucleophilicity scale and the YCl solvent ionizing scale, with sensitivity values of 1.28 ± 0.06 and 0.46 ± 0.03 for l and m, respectively. The activation enthalpies (ΔH≠) are 10.1 to 12.8 kcal·mol−1 and the activation entropies (ΔS≠) are −27.8 to −36.8 cal·mol−1·K−1, which is consistent with the proposed bimolecular reaction mechanism. The kinetic solvent isotope effect (kMeOH/kMeOD) of 2.39 is also in accord with SN2 mechanism probably assisted by general-base catalysis.

【 授权许可】

Unknown