高等学校化学学报 ›› 2018, Vol. 39 ›› Issue (4): 749.doi: 10.7503/cjcu20170463

• 物理化学 • 上一篇    下一篇

双层三明治四聚吡咯铀配合物的结构设计和稳定性理论计算

田琳飞1, 张春华2, 曲宁1, 毕艳婷1, 张红星3(), 潘清江1()   

  1. 1. 黑龙江大学功能无机材料化学教育部重点实验室, 化学化工与材料学院, 哈尔滨 150080
    2. 黑龙江省大庆水文局水环境监测分中心, 大庆 163311
    3. 吉林大学理论化学研究所, 长春 130023
  • 收稿日期:2017-07-14 出版日期:2018-04-10 发布日期:2018-03-16
  • 作者简介:联系人简介: 张红星, 男, 博士, 教授, 博士生导师, 主要从事理论与应用量子化学方面的研究. E-mail:zhanghx@jlu.edu.cn;潘清江, 男, 博士, 教授, 主要从事锕系分子科学与光电材料设计方面的研究. E-mail:panqjitc@163.com
  • 基金资助:
    国家自然科学基金(批准号: 21273063, 21573088)和黑龙江省留学回国人员科技项目择优资助

Theoretical Studies of Structural Design and Stability of Double-layered Sandwich-like Tetrapyrrolic Uranium Complexes

TIAN Linfei1, ZHANG Chunhua2, QU Ning1, BI Yanting1, ZHANG Hongxing3,*(), PAN Qingjiang1,*()   

  1. 1. Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education,School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, China
    2. Water Environment Monitoring Branch Center,Daqing Hydrographic Bureau of Heilongjiang Province, Daqing 163311, China
    3. Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
  • Received:2017-07-14 Online:2018-04-10 Published:2018-03-16
  • Contact: ZHANG Hongxing,PAN Qingjiang E-mail:zhanghx@jlu.edu.cn;panqjitc@163.com
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.21273063, 21573088) and the Scientific Foundation of Heilongjiang Province for the Returned Overseas Chinese Scholars, China

摘要:

为探索四聚吡咯配体和低价铀离子相互作用, 以实验合成单层三明治结构配合物PcUPc(Pc=酞菁)为基础, 设计双层三明治型PzUmPzUmPz(m=Ⅲ, Ⅳ, Pz=氮杂卟啉), 采用相对论密度泛函理论考察了其几何结构、 异构体相对稳定性以及成键和轨道性质. 得到se(staggered-eclipsed)和es(eclipsed-staggered) 2种类型稳定空间异构体, 并进一步优化其所有可能的电子自旋态异构体. 计算结果表明, 这些低价铀配合物均具有五重态基态. 分子中的原子量子理论(quantum theory of atoms in molecule, QTAIM)在U-N键临界点处的电子/能量密度拓扑分析显示U-N键为弱极性共价键. 四价配合物拥有4个U(5f)性质高能占据轨道, 与2个U4+的5f单电子数相一致; 而三价配合物有很大配体参与作用. 2个铀原子和中间Pz配体质心近似成线性, 这与配合物具有稳定的σ(U-U)成键轨道密切相关.

关键词: 三明治型四聚吡咯低价铀配合物, 异构体稳定性, 分子中的原子量子理论(QTAIM), 电子结构, 相对论密度泛函理论

Abstract:

To explore the interaction between tetrapyrrolic ligand and low-valent uranium ion, double-layered Sandwich-like complexes PzUmPzUmPz(labeled as $U^{m}_{2}$ Pz3; m=Ⅲ and Ⅳ, Pz=porphyrazine) were designed according to the single-layered PcUPc(Pc=phthalocyanine) that was experimentally synthesized. Relativistic density functional theory(RDFT) was used to examine structures, stability and chemical bonding. It is shown that complexes $U^{m}_{2}$Pz3 have the quintet ground state. Steric configurations are found to have a little effect on isomeric stability, while electron-spin states play more important role. Topological analyses of electron density suggest weakly polarized covalent character for U-N bonds. Tetravalent diuranium complex possesses four U(5f)-character high-lying occupied orbitals, in accordance with U 5f-electron number counting. Differently, some electron transfer from uranium to ligand(Pz) is unraveled for the trivalent complex, leading to more ligand contribution to frontier molecular orbitals.

Key words: Sandwich-like tetrapyrrolic uranium complex, Stability of isomer, Quantum theory of atoms in molecule(QTAIM), Electronic structure, Relativistic density functional theory

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