| 硅杂原子提升冠醚对锂离子络合能力的机理理论研究 |
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| 引用本文： | 梁苏卓成,姬国勋,孙新利,王波,张仕通,代星.硅杂原子提升冠醚对锂离子络合能力的机理理论研究[J].化工学报,2021,72(6):3149-3159. |
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| 作者姓名： | 梁苏卓成 姬国勋 孙新利 王波 张仕通 代星 |
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| 作者单位： | 1.西安高科技研究所，陕西 西安 710025;2.苏州大学放射医学与辐射防护国家重点实验室，放射医学及交叉学科研究院，江苏省高校放射医学协同创新中心，江苏 苏州 215123;3.东北电力大学理学院，吉林省 吉林市 132012 |
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| 基金项目： | 国家自然科学基金项目(22076219);吉林省优秀青年人才基金项目(20180520172JH) |
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| 摘 要： | 将Si引入冠醚有希望大幅度提升其对阳离子的络合能力，但其中的调控机理尚不清晰。基于量子化学密度泛函理论计算，以12-冠-4、1，1-2甲基-1-硅杂12-冠-4、1，1，2，2-4甲基-1，2-2硅杂12-冠-4、1，1，2，2，4，4，5，5-8甲基-1，2，4，5-4硅杂12-冠-4和1，1，2，2，7，7，8，8-8甲基-1，2，7，8-4硅杂12-冠-4络合Li+为计算模型，探究了冠醚与Li+之间的相互作用机理。结果表明，由于O—Li+配位键的键长增加，掺杂Si的数量为2和4的Si杂12-冠-4对Li+的共价相互作用略弱，但静电相互作用和色散相互作用更强、Pauli排斥作用更小，最终导致所有Si杂12-冠-4对Li+的络合能力都比12-冠-4更强。上述有利因素源于Si—O键中Si的电子显著向O极化，同时，Si杂12-冠-4中—SiMe2—SiMe2—和—CH2—SiMe2—单元远离Li+，有效避免了Si—Li+之间的静电排斥。揭示的冠醚-Li+相互作用机理将为未来设计与合成杂原子冠醚提供理论指导。
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| 关 键 词： | 冠醚 锂离子 硅 杂原子 吸附 吸附剂 计算化学 |
| 收稿时间： | 2021-01-08 |
Theoretical study on mechanism of silicon heteroatoms to improve the complexation ability of crown ethers to lithium ions |
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| LIANG-SU Zhuocheng,JI Guoxun,SUN Xinli,WANG Bo,ZHANG Shitong,DAI Xing.Theoretical study on mechanism of silicon heteroatoms to improve the complexation ability of crown ethers to lithium ions[J].Journal of Chemical Industry and Engineering(China),2021,72(6):3149-3159. |
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| Authors: | LIANG-SU Zhuocheng JI Guoxun SUN Xinli WANG Bo ZHANG Shitong DAI Xing |
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| Affiliation: | 1.Xi’an Research Institute of Hi-Tech, Xi’an 710025, Shaanxi, China;2.State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, Jiangsu, China;3.College of Science, Northeast Electric Power University, Jilin 132012, Jilin, China |
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| Abstract: | Doping Si atoms into crown ethers has the potential to greatly enhance their complexation ability to metal ions, but the regulation mechanism is still unclear. 12-Crown-4, 1,1-demethyl-1-sila-12-crown-4, 1,1,2,2-tetramethyl-1,2-disila-12-crown-4, 1,1,2,2,4,4,5,5-octamethyl-1,2,4,5-tetrasila-12-crown-4 and 1,1,2,2,7,7,8,8-octamethyl-1,2,7,8-tetrasila-12-crown-4 were selected as the models and the interactions between crown ethers and Li+ were deeply studied by quantum chemical density functional theory calculations. The results show that due to the increase of the O—Li+ coordination bond length, the covalent interactions of the 12-crown-4 with two or four Si atoms are slightly weaker, but the electrostatic interactions and dispersion interactions are stronger, and the Pauli repulsions are smaller, which ultimately lead to the stronger interaction between all the Si hetero12-crown-4 and Li+ than 12-crown-4. The above mentioned favorable factors stem from the fact that the electrons of the weakly electronegative Si in the Si—O bond are significantly polarized toward O, which enhances the advantage of O's negative electrostatic potential. Meanwhile, the complexion of Si hetero12-crown-4 with Li+ causes the —SiMe2—SiMe2— or —CH2—SiMe2— units to be away from Li+, effectively avoiding the Coulombic repulsion between Si—Li+. The crown ether-Li+ interaction mechanism revealed in this work will provide theoretical guidance for the future designing and synthesizing of heteroatom crown ethers with efficient extraction capabilities. |
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| Keywords: | crown ether lithium-ion silicon heteroatom adsorption sorbents computational chemistry |
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