水溶液中取代乙酸的量化研究

The Quantum Study of Substited Acetic Acids in aqueous solution

本文应用量子化学理论，超分子方法和ＣＮＤＯ／２计算方法，结合回归分析研究水溶液中取代乙酸的酸性与分子的电子结构关系。从而从量化角度解释水溶液中取代乙酸的酸性及其变化规律。结果表明：水溶液中取代乙酸的氢原子电荷ＱＨ与ｐＫａ有很好的相关关系。羧酸的酸性可用ＱＨ来衡量。羧基氢原子与水分子形成氢键是影响水溶液中羧酸酸性变化的主要因素。

This paper Uses CNDO/2 and supermolecules approach to study the relationship between electronic structures and the acidity of substited acetic acids in aqueous solution. The result indicate that there is a good correlation between pKa and atomic charge Q H of carboxyl hydrogen in aqueous solution, the hydrogen bond between carboxyl hydrogen and water reflects the acidities of substited Acetic Acids in aqueous solution.