Liu Yan-Zhi, Yuan Kun, Liu Liu, Yuan Zhao, Zhu Yuan-Cheng
College of Chemical Engineering and Technology, Tianshui Normal University , Tianshui 741001, China.
Institute for Chemical Physics & Department of Chemistry, School of Mechanical Engineering, Xi'an Jiaotong University , Xi'an 710049, China.
J Phys Chem A. 2017 Feb 2;121(4):892-900. doi: 10.1021/acs.jpca.6b12342. Epub 2017 Jan 23.
Anion recognitions between common anions and a novel pincer-like receptor (N,N'-bis(5-fluorobenzoyloxyethyl)urea, BFUR) were theoretically explored, particularly on geometric features of the BFUR@X (X = F, Cl, Br, I, CO, NO, and SO) systems at a molecular level in this work. Complex structures show that two N-H groups as a claw and two -CF rings on BFUR as a pair of tweezers simultaneously interact with captured anions through cooperative double-dentate hydrogen bond and double-side anion-π interactions. The binding energies and thermodynamic information indicate that the recognitions of the seven anions by BFUR in vacuum are enthalpy-driven and entropy-opposed, which occur spontaneously. Although the binding energy ΔE between F and BFUR is relatively high (289.30 kJ·mol), ΔE, ΔG, and ΔH of the recognition for CO and SO are much larger than the cases of F, Cl, Br, I, and NO, suggesting that BFUR is an ideal selective anion receptor for CO and SO. Additionally, energy decomposition analysis based on localized molecular orbital energy decomposition analysis (LMO-EDA) was performed; electronic properties and behaviors of the present systems were further discussed according to calculations on frontier molecular orbital, UV-vis spectra, total electrostatic potential, and visualized weak interaction regions. The present theoretical exploration of BFUR@X (X = F, Cl, Br, I, CO, NO, and SO) systems is fundamentally crucial to establish an anion recognition structure-property relationship upon combination of different noncovalent interactions, that is, double-dentate hydrogen bond and double-side anion-π interactions.
本文从理论上探究了常见阴离子与一种新型钳状受体（N,N'-双(5-氟苯甲酰氧基乙基)脲，BFUR）之间的阴离子识别作用，尤其在分子水平上研究了BFUR@X（X = F、Cl、Br、I、CO、NO和SO）体系的几何特征。复杂结构表明，BFUR上的两个N-H基团作为爪子，两个-CF环作为一对镊子，通过协同双齿氢键和双侧阴离子-π相互作用同时与捕获的阴离子相互作用。结合能和热力学信息表明，BFUR在真空中对七种阴离子的识别是由焓驱动且熵相反的，是自发发生的。尽管F与BFUR之间的结合能ΔE相对较高（289.30 kJ·mol），但CO和SO识别的ΔE、ΔG和ΔH远大于F、Cl、Br、I和NO的情况，这表明BFUR是CO和SO的理想选择性阴离子受体。此外，基于定域分子轨道能量分解分析（LMO-EDA）进行了能量分解分析；根据前线分子轨道、紫外可见光谱、总静电势和可视化弱相互作用区域的计算，进一步讨论了本体系的电子性质和行为。对BFUR@X（X = F、Cl、Br、I、CO、NO和SO）体系的本理论探索对于在不同非共价相互作用（即双齿氢键和双侧阴离子-π相互作用）结合的基础上建立阴离子识别结构-性质关系至关重要。
