Department of Chemistry, Payame Noor University, PO Box 19395-3697 Tehran, Iran.
Acta Crystallogr C Struct Chem. 2020 Oct 1;76(Pt 10):982-991. doi: 10.1107/S2053229620012589. Epub 2020 Sep 28.
The present work utilizes density functional theory (DFT) calculations to study the influence of cation-π interactions on the electronic properties of the complexes formed by Altretamine [2,4,6-tris(dimethylamino)-1,3,5-triazine], an anticancer drug, with mono- and divalent (Li, Na, K, Be, Mg and Ca) metal cations. The structures were optimized with the M06-2X method and the 6-311++G(d,p) basis set in the gas phase and in solution. The theory of `Atoms in Molecules' (AIM) was applied to study the nature of the interactions by calculating the electron density ρ(r) and its Laplacian at the bond critical points. The charge-transfer process during complexation was evaluated using natural bond orbital (NBO) analysis. The results of DFT calculations demonstrate that the strongest/weakest interactions belong to Be/K complexes. There are good correlations between the achieved densities and the amounts of charge transfer with the interaction energies. Finally, the stability and reactivity of the cation-π interactions can be determined by quantum chemical computation based on the molecular orbital (MO) theory.
本工作利用密度泛函理论（DFT）计算研究了阳离子-π 相互作用对抗癌药物氨柔比星[2,4,6-三（二甲氨基）-1,3,5-三嗪]与一价和二价（Li、Na、K、Be、Mg 和 Ca）金属阳离子形成的配合物电子性质的影响。采用 M06-2X 方法和 6-311++G(d,p)基组在气相和溶液中对结构进行了优化。通过计算键临界点处的电子密度 ρ(r)及其拉普拉斯值，应用分子中的原子（AIM）理论研究了相互作用的性质。通过自然键轨道（NBO）分析评估了配合物过程中的电荷转移。DFT 计算结果表明，最强/最弱相互作用属于 Be/K 配合物。所得密度与电荷转移量之间存在良好的相关性，与相互作用能相关。最后，可以基于分子轨道（MO）理论通过量子化学计算来确定阳离子-π 相互作用的稳定性和反应性。
