“温度-压力-溶剂”对Al(H_2O)_6^(3+)动态水交换反应影响的密度泛函理论研究  

Influences of temperature,pressure and solvent on the waterexchange reactions of Al(H_2O)_6^(3+) by density functional theory

作　　者：张婧[1] 董绍楠 侯晓霞[1] 袁晓涵 毕树平[1] ZHANG Jing;DONG Shaonan;HOU Xiaoxia;YUAN Xiaohan;BI Shuping(School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China)

机构地区：[1]南京大学化学化工学院,南京210023

出　　处：《环境化学》2018年第6期1179-1185,共7页Environmental Chemistry

基　　金：国家自然科学基金(21177054)资助~~

摘　　要：采用密度泛函理论(DFT)对不同温度、压力和溶剂条件下的Al(H_2O)_6^(3+)水交换反应进行了研究,系统地开展了以下工作:(1)采用超分子-极化连续模型在B3LYP/6-311+G(d,p)基组水平下优化得到Al(H_2O)_6^(3+)水交换反应的路径,在优化构型的基础上计算得到5组温度(278—358 K)条件下相应的水交换反应速率常数kex,结果表明温度升高促进了Al(H_2O)_6^(3+)水交换反应的进行;(2)计算得到5组压力(0.4—1.2 atm)条件下Al(H_2O)_6^(3+)水交换反应的kex,研究表明在该地表水中常压范围内的压力变化对kex没有影响;(3)在极化连续模型下进行单点能计算时分别选择水、乙腈、乙醇、苯和四氯化碳等5种不同的主体溶剂,计算不同溶剂中Al(H_2O)_6^(3+)水交换反应的kex,结果表明非极性溶剂中反应的活化Gibbs自由能较低,水交换速率加快.本文为不同环境条件下Al(H_2O)_6^(3+)水交换反应的研究提供了有用参考.Influences of temperature,pressure and solvent on the water-exchange reaction of Al（H2O）6^3＋ were investigated using density functional theory（DFT）.Systematic studies were conducted in this work：（1） The water-exchange reaction of Al（H2O）6^3＋ was simulated at B3LYP/6-311＋G（d,p） level with gas phase-supermolecule-polarizable continuum model（GP-SM-PCM）.Based on the optimized structures,the water-exchange rate constants kexat five different temperatures（278—358 K） were calculated,and results indicated that the increase of temperature accelerated the water-exchange rates of Al（H2O）6^3＋;（2） The kexunder five different pressures（0.4—1.2 atm）were computed as well,and the results demonstrated that the pressure had no influence on the kex within the normal atmospheric pressure in the surface water;（3） Five solvents were considered when calculating single-point energies with polarizable continuum model（PCM）.They were water,acetonitrile,ethanol,benzene and carbon tetrachloride（CCl4）,respectively.The corresponding kex values implied that the water-exchange rates of Al（H2O）6^3＋ in the nonpolar solvents were faster thanthose in the polar solvents.This work provides a useful reference for the investigation on the waterexchange reaction of Al（H2O）6^3＋ under different environmental conditions.

关 键 词：Al(H2O)^63+水交换反应 密度泛函理论 温度 压力 溶剂 

分 类 号：O641.1[理学—物理化学]