Enhancing Effects of Electron-Withdrawing Groups and Metallic Ions on Halogen Bonding in the YC6F4X路路路C2H8N2 (X = Cl, Br, I; Y = F, CN, NO2<

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• 作者：Na Han ; Yanli Zeng ; Xiaoyan Li ; Shijun Zheng ; Lingpeng Meng
• 刊名：Journal of Physical Chemistry A
• 出版年：2013
• 出版时间：December 5, 2013
• 年：2013
• 卷：117
• 期：48
• 页码：12959-12968
• 全文大小：533K
• 年卷期：v.117,no.48(December 5, 2013)
• ISSN：1520-5215

文摘

Halogen-bonding interactions are highly directional intermolecular interactions that are often important in crystal engineering. In this work, the second-order M酶ller鈥揚lesset perturbation theory (MP2) calculations and the quantum theory of 鈥渁toms in molecules鈥?(QTAIM) and noncovalent interaction (NCI) studies were carried out on a series of X路路路N halogen bonds between substituted haloperfluoroarenes C₆F₄XY (X = Cl, Br, I; Y = F, CN, NO₂) as bond donors and 1,2-diaminoethane as bond acceptor. Our research supports earlier work that electron-withdrawing substituents produce an enhancement effect on the size of the 蟽-hole and the maximum positive electrostatic potentials (V_S,max), which further strengthens the halogen bonding. The metallic ion M⁺ (M⁺ = Li⁺, Na⁺) has the ability to enhance the size of both the 蟽-hole and V_S,max value with the formation of [MNCC₆F₄X]⁺, resulting in more electronic charge transfer away from the halogen atom X and an increase in the strength of the halogen bond. It is found that the values of V_S,max at the 蟽-holes are linear in relation to the halogen-bonded interaction energies and the halogen-bonding interaction distance, indicating that the electrostatic interaction plays a key role in the halogen-bonding interactions. The values of V_S,max at the 蟽-holes are also linear in relation to the electron density 蟻_b, its Laplacian ²蟻_b, and 鈭?i>G_b/V_b of XB, indicating that the topological properties (蟻_b, ²蟻_b) and energy properties (G_b, V_b) at the BCPs are correlated with the electrostatic potentials.