基于密度泛函理论揭示Cu^(2+)配位作用对头孢拉定水解反应的影响机制  

Effects of Cu^(2+)complexation on the structure and hydrolysis of cephradine using density functional theory

作　　者：张海勤[1] 谢宏彬[1] 陈景文[1] 张树深[1] 

机构地区：[1]工业生态与环境工程教育部重点实验室大连理工大学环境学院,大连116024

出　　处：《环境化学》2015年第9期1594-1600,共7页Environmental Chemistry

基　　金：国家重点基础研究发展计划(2013CB430403);国家自然科学基金(21137001;21325729)资助

摘　　要：基于密度泛函理论(DFT,Density functional theory),计算了水中Cu2+与抗生素头孢拉定的配位作用,发现Cu2+与头孢拉定可形成1∶1配合物,该配合物存在两种形态:Cu2+与头孢拉定分子支链氨基氮原子和羰基氧原子配位,同时结合一个水分子;Cu2+与羧基氧原子和内酰胺氧原子配位,同时结合两个水分子.结果表明,Cu2+的配位作用能增大头孢拉定水解反应位点正电荷量,降低水解前线分子轨道能级差和活化能,从而促进头孢拉定水解,该结果得到了实验证实.因此,DFT可用于预测Mn+配位作用对药物和个人护理用品(PPCPs,Pharmaceutical and personal care products)等有机污染物水解的影响,对于PPCPs类有机污染物的生态风险评价具有重要意义.Density functional theory （ DFT） was employed to investigate the complexation effects of Cu2＋ on hydrolysis of cephradine. We found that two complex species were formed, with the binding sites being a ） the amino and carbonyl group, and b ） the carboxyl group and carbonyl group, respectively. This complexation changed the bond length of lactam, increased the positive charge of the hydrolysis site, and reduced both the energy gap of the frontier molecular orbitals for hydrolysis and the activation energy of base-catalyzed hydrolysis. Thus, the complexation of Cu2＋ can catalyze the hydrolysis of cephradine. The prediction was confirmed by experimental results. Thus, the DFT calculation can be employed to predict the effects of metal complexation on the hydrolysis of organic pollutants, which are important in the ecological risk assessment of organic chemicals.

关 键 词：配位作用 CU2+ 头孢拉定 密度泛函理论 水解 

分 类 号：X131.2[环境科学与工程—环境科学]