Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Spain.
ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.
Chemphyschem. 2020 Sep 15;21(18):2112-2126. doi: 10.1002/cphc.202000434. Epub 2020 Aug 17.
For many years, non-covalently bonded complexes of nucleobases have attracted considerable interest. However, there is a lack of information about the nature of hydrogen bonding between nucleobases when the bonding is affected by metal coordination to one of the nucleobases, and how the individual hydrogen bonds and aromaticity of nucleobases respond to the presence of the metal cation. Here we report a DFT computational study of nucleobase pairs interacting with alkali metal cations. The metal cations contribute to the stabilization of the base pairs to varying degrees depending on their position. The energy decomposition analysis revealed that the nature of bonding between nucleobases does not change much upon metal coordination. The effect of the cations on individual hydrogen bonds were described by changes in VDD charges on frontier atoms, H-bond length, bond energy from NBO analysis, and the delocalization index from QTAIM calculations. The aromaticity changes were determined by a HOMA index.
多年来，碱基的非共价键复合物一直引起人们的极大兴趣。然而，当键合受到金属与其中一个碱基的配位的影响时，关于碱基之间氢键的性质以及碱基的氢键和芳香性如何响应金属阳离子的存在，我们知之甚少。在这里，我们报告了一个 DFT 计算研究，研究了与碱金属阳离子相互作用的碱基对。金属阳离子根据其位置对碱基对的稳定化程度不同。能量分解分析表明，金属配位后碱基之间的键合性质变化不大。通过前线原子的 VDD 电荷、氢键长度、NBO 分析的键能以及 QTAIM 计算的离域指数的变化，描述了阳离子对单个氢键的影响。芳香性的变化由 HOMA 指数确定。
