镍、锌、钴(Ⅱ)-N-(对位取代苯基)亚氨基二乙酸的量热

Calorimetric Study of Ni(Ⅱ), Co(Ⅱ), Zn(Ⅱ)-N-(para-substituted Phenyl) Iminodiacetic Acid

使用改进的RD－1型热导式量热计测定了镍（Ⅱ）-、钴（Ⅱ）-、锌（Ⅱ）－N－（对位取代苯基）亚氨基二乙酸等三个二元配位体系的生成热．这些配合物的生成热不仅与配体的质子化热之间存在着线性关系，而且它们的大小按金属离子来说是完全符合Irving－Williams序列的，并利用配体的多环水化结构解释了N－（取代苯基）亚氨基二乙酸根质子化热呈正值（吸热）的实验事实。

The formation heats of binary complex compounds formed from N-(para substituted phenyl) iminodiacetic acid (p-RPhIDA) with Ni(Ⅱ), Co(Ⅱ) and Zn(Ⅱ) have been determined by means of a model RD-1 conduction automatic calorimeter at 25.0±0.2 ℃ in the presence of KNO3 (0.1 mol·L-1). It was found that linear enthalpy relation ships not only did exist between the formation heats of the binary complex compounds (Ni(Ⅱ )-, Co(Ⅱ)-, Zn(Ⅱ)-p-RPhIDA) and the protonation heats of p-RPhIDA but the order of maghitude of these formation heats is in agreement with Irving-Williams order for the metal ions. The experimental fact of positive (endothermic) protonation heats of p-RPHIDA has been explained by means of polyring hydration structure of N-(para substituted phenyl) iminodiacetate.