Substituent effects. 14. Anomalous dissociation constants in water-organic solvent mixtures: Benzylammonium ions and related systems
作者:A. J. Hoefnagel、R. H. de Vos、B. M. Wepster
DOI:10.1002/recl.19921110103
日期:——
Thermodynamic dissociation constants in various water-organic solvent mixtures are given for benzylammonium, benzyldialkylammonium, and (2-phenylethyl)ammonium ions. Deviations from the Hammett equation (Eqn. 1) are similar to those observed for carboxylic acids, but of opposite sign. The extended Hammett equation (Eqn. 3), containing the hydrophobic constant, π, yields good correlations. Derived secondary
给出了对于苄基铵,苄基二烷基铵和(2-苯乙基)铵离子的各种水-有机溶剂混合物中的热力学解离常数。与Hammett方程(方程式1)的偏差与对羧酸观察到的偏差相似,但符号相反。包含疏水常数π的扩展Hammett方程(等式3)产生了良好的相关性。举例说明了派生的次级正常sigma值。