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过程工程学报 ›› 2021, Vol. 21 ›› Issue (2): 144-152.DOI: 10.12034/j.issn.1009-606X.220076

• 反应与分离 • 上一篇    下一篇

硫杂冠醚对Ag(I)和Tl(I)的萃取

程衔锟1， 熊延杭1， 侯 雪1， 田 欢1， 田勇攀1， 徐 亮1,2， 赵 卓1*   

  1. 1. 安徽工业大学冶金工程学院，安徽 马鞍山 243000 2. 上海大学省部共建高品质特殊钢冶金与制备国家重点实验室，上海 200444
  • 收稿日期:2020-03-06 修回日期:2020-04-16 出版日期:2021-02-22 发布日期:2021-03-01
  • 通讯作者: 赵卓 zhaozhuo1018@163.com
  • 基金资助:
    MgCl26H2O-Mg(OH)2-MgO技术路线制备高纯镁砂过程基础研究;MgCl26H2O-Mg(OH)2-MgO技术路线制备高纯镁砂过程基础研究;安徽省高校优秀青年人才支持计划(重点)

Extraction of Ag(I) and Tl(I) by thiacrown ether

Xiankun CHENG1, Yanhang XIONG1, Xue HOU1, Huan TIAN1, Yongpan TIAN1, Liang XU1,2, Zhuo ZHAO1*   

  1. 1. School of Metallurgical Engineering, Anhui University of Technology, Ma′anshan, Anhui 243000, China 2. State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200444, China
  • Received:2020-03-06 Revised:2020-04-16 Online:2021-02-22 Published:2021-03-01

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摘要： 基于冠醚的配位化学及软硬酸碱理论，设计并合成了五种硫杂冠醚，系统研究了其对Ag(I)和Tl(I)两种软酸离子的络合能力。模拟计算结果表明，五种冠醚与Ag(I)和Tl(I)络合后构型均发生了转变，且结构优化后的五种冠醚与Ag(I)络合过程的ΔG和ΔU均较负，表现出了一定的配位能力，而与Tl(I)络合过程的ΔG和ΔU均接近于0，配位能力相对较差。五种冠醚对Ag(I)和Tl(I)的萃取实验结果表明，五种冠醚对Ag(I)的络合常数分别为3.97, 6.58, 20.61, 9.76, 13.40，对Tl(I)的络合常数分别为4.24, 4.65, 5.80, 4.77, 4.33；在复杂体系中，冠醚2, 3, 4, 5对Ag(I)均具有较高的萃取率及选择性识别能力，而冠醚1对Ag(I)表现出较差的选择性识别能力。五种冠醚对Tl(I)几乎不具有选择性萃取能力。

关键词: 配位化学, 硫杂冠醚, 选择性识别, 萃取, 结构模拟

Abstract: Based on the coordination chemistry of crown ether and soft and hard acid-base theory (HSAB) of crown ether, five kinds of thiacrown ethers were designed and synthesized. And their complexation abilities to two soft acid ions-Ag(I) and Tl(I) were systematically investigated. Firstly, the five crown ethers and their complexes with Ag(I) and Tl(I) complexes were optimized by Gaussian 16 software. On this basis, the Gibbs free energy change (ΔG), enthalpy change (ΔH), internal energy change (ΔU) and other thermodynamic parameters of the complexation process of five sulfur crown ethers with Ag(I) and Tl(I) at 298.15 K were calculated. The simulation results showed that the five thiacrown ethers had changed after being complexed with Ag(I) and Tl(I), and the ΔG and ΔU of the five crown ethers after structural optimization were negative in the complexation process with Ag(I), showing a certain coordination ability. However, during the complexation with Tl(I), ΔG and ΔU were close to 0, and the coordination ability was relatively poor. On the basis of simulation calculation, the extraction ability of five crown ethers on Ag(I) and Tl(I) was investigated by solvent extraction. The experimental results showed that the complex constants of five thiacrown ethers for Ag(I) were 3.97, 6.58, 20.61, 9.76, 13.40, respectively in the single system. In the multi-system, thiacrown ethers 2, 3, 4, and 5 had higher extraction rate and selective recognition ability for Ag(I), while thiacrown ether 1 exhibited poor selective recognition ability for Ag(I), this may be due to the small cavity of thiacrown ether 1. However, the five thiacrown ethers had almost no selectivity for Tl(I), this may be related to the coordination properties of Tl(I). Finally, combined with the simulation results and extraction experiments, the extraction mechanism of five crown ethers on Ag(I) and Tl(I) was analyzed in detail.

Key words: coordination chemistry, thiacrown, selective recognition, extraction, structural simulation