Hou Hui, Zeng Xingye, Liu Xiaoping
College of Chemistry, Beijing Normal University, Beijing, China.
J Mol Model. 2009 Feb;15(2):105-11. doi: 10.1007/s00894-008-0379-8. Epub 2008 Nov 13.
The molecular and electronic structures for 12- to 16-crown-4 (named 12C4, 13C4, 14C4, 15C4, 16C4, respectively) and 2,3,5,6,8,9-hexahydrobenzo[b][1,4,7,10] tetraoxacyclododecine (B12C4) 3,5,6,7,9,10-hexahydro-2H-benzo[e][1,4,7,10]tetraoxacyclotridecine (B13C4) and their complexes with alkali metal cations Li+ and Na+ have been explored using the density functional theory (DFT) with B3LYP/ 6-31G* method. The nucleophilicity of crown-4 ethers has been investigated by the Fukui function. Their selectivity trend shows that of all the crown-4 ethers, 14C4 shows the highest cation selectivity for Li+ over Na+, has been achieved on the basis of thermodynamic analysis. In addition, Li+/crown-4 series are more stable than Na+/crown-4 series in the gas phase. The calculated results are in good agreement with the experimental observation.
采用密度泛函理论（DFT）的B3LYP/6 - 31G*方法，对12至16元环-4（分别命名为12C4、13C4、14C4、15C4、16C4）以及2,3,5,6,8,9 - 六氢苯并[b][1,4,7,10]四氧杂环十二烯（B12C4）、3,5,6,7,9,10 - 六氢-2H - 苯并[e][1,4,7,10]四氧杂环十三烯（B13C4）及其与碱金属阳离子Li⁺和Na⁺的配合物的分子和电子结构进行了研究。利用福井函数研究了冠-4醚的亲核性。它们的选择性趋势表明，在所有冠-4醚中，14C4对Li⁺相对于Na⁺表现出最高的阳离子选择性，这是基于热力学分析得出的。此外，在气相中，Li⁺/冠-4系列比Na⁺/冠-4系列更稳定。计算结果与实验观察结果吻合良好。
