( 1. 华东理工大学 生物化学研究所， 上海 200237;
2. 中南大学 资源加工与生物工程学院， 长沙 410083)
摘 要: 运用密度泛函理论(DFT) B3LYP方法， 取6-31G*基组， 对苯氧乙酸类浮选抑制剂分子进行了量子化学计算。通过官能团羧基的键电荷密度及其比值ρ(O—H)/ρ(C—O)的计算， 比较了各药剂分子离解成一价负离子的难易。 根据各分子的前线轨道能量差ΔEHOMO-LUMO和一价负离子的HOMO能级， 对分子的反应活性、 一价负离子与矿物表面不同金属离子作用的强弱进行了比较。从药剂与矿物表面作用前后的能量变化， 比较了各药剂的一价负离子与不同矿物表面发生作用的稳定性， 并通过对比矿物与捕收剂作用后的能量变化， 证明苯氧乙酸类抑制剂对方解石的抑制作用是靠抑制剂在矿物表面强烈的化学吸附而形成的。
关键字: 苯氧乙酸; 密度泛函理论; 键电荷密度; 量子化学计算
（ 1. Research Institute of Biochemistry,
East China University of Science and Technology, Shanghai 200237, China;
2. School of Resources Processing and Bioengineering,
Central South University, Changsha 410083, China）
Abstract: Quantum chemistry of phenoxy acetic acids depressants was studied at B3LYP/6-31G* level by density functional theory(DFT). The ratio of bond charge density(ρ(O—H)/ρ(C—O)) for dissociating carboxylic group in each reagent was put out as the judgment for dissociation extent. Frontier orbital energy calculation of the reagents and their corresponding univalence anions approved the traditional theory that molecules in lower ΔEHOMO-LUMO has greater reactivity, and that univalence anion in lower HOMO energy causes greater reactivity with active metal ion on the mineral surface. Energy variation between the univalence anion and the mineral surface reveals that such reagents make intensive adsorption on the surface of calcite and diaspore.
Key words: phenoxy acetic acid; density functional theory; bond charge density; quantum chemistry calculation
