( 1. 華東理工大學 生物化學研究所， 上海 200237;
2. 中南大學 資源加工與生物工程學院， 長沙 410083)
摘 要: 運用密度泛函理論(DFT) B3LYP方法， 取6-31G*基組， 對苯氧乙酸類浮選抑制劑分子進行了量子化學計算。通過官能團羧基的鍵電荷密度及其比值ρ(O—H)/ρ(C—O)的計算， 比較了各藥劑分子離解成一價負離子的難易。 根據(jù)各分子的前線軌道能量差ΔEHOMO-LUMO和一價負離子的HOMO能級， 對分子的反應(yīng)活性、 一價負離子與礦物表面不同金屬離子作用的強弱進行了比較。從藥劑與礦物表面作用前后的能量變化， 比較了各藥劑的一價負離子與不同礦物表面發(fā)生作用的穩(wěn)定性， 并通過對比礦物與捕收劑作用后的能量變化， 證明苯氧乙酸類抑制劑對方解石的抑制作用是靠抑制劑在礦物表面強烈的化學吸附而形成的。
關(guān)鍵字: 苯氧乙酸; 密度泛函理論; 鍵電荷密度; 量子化學計算
XU Jing2, WANG Dian-zuo2
（ 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
