14-冠-4冠醚衍生物与Li(I)的络合过程理论研究

Theoretical research for the 14-crown-4 crown ether derivatives with Li(I)

臂式冠醚由于其侧臂基团可以不同程度改变冠醚的供电子能力、冠醚环的构象、亲水性等,从而使其与金属离子的络合性能发生变化。以二苯并14-冠-4冠醚(DB14C4)为基础,选取羟基(-OH)、氨基(-NH 2)、羟甲基(-CH 2OH)、氨甲基(-CH 2NH 2)四种侧臂基团,基于密度泛函理论(DFT),在水溶剂模型下,研究了不同侧臂基团对DB14C4与Li(I)络合过程的影响.从结构优化、前线轨道(HOMO、LUMO)及静电势(ESP)、独立梯度函数(IGM)方面进行了分析.结果表明,羟甲基的引入可改善冠醚的配位能力,为高选择性冠醚的设计提供理论支持.

The lariat crown ether s chelate capacity with metal ions can be varied with the change of the electron donating ability of the crown ether,the flexibility of the ring,the hydrophilicity,etc.Based on DB14C4,this thesis selects four kinds of lariat groups-OH,-NH 2,-CH 2OH and-CH 2NH 2.Besides,based on Density Functional Theory(DFT),this thesis studies the effects of different lariat groups on the complexation between DB14C4 and Li(I)in aqueous phase.From the aspects of structural optimization,frontier orbit(HOMO,LUMO),electrostatic potential(ESP)and independent gradient model(IGM).It is found that the coordination ability of crown ether is improved after the modification of-CH 2OH group.Besides,crown ether structures with selective complexing ability can be designed targetedly.