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Structures and Uranium-Uranium Multiple Bond of Binuclear Divalent Uranium Complex of Pyrrolic Schiff-base Macrocycle: a Relativistic DFT Probe
文献类型：期刊论文
| 作者 | Pan, QJ; Shi, WQ ; Zhang, HX; Wu, QY; Wu HY(吴海燕); Qu, N; Chen, FY; Shi WQ(石伟群)
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| 刊名 | ACTA CHIMICA SINICA化学学报
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| 出版日期 | 2017 |
| 卷号 | 75期号:5页码:457-+ |
| 关键词 | bimetallic U-II polypyrrolic complexes electronic structures diuranium multiple bond QTAIM relativistic DFT |
| ISSN号 | 0567-7351 |
| DOI | 10.6023/A17010008 |
| 其他题名 | 二价双核铀聚吡咯配合物结构设计和铀-铀多重键的理论研究 |
| 文献子类 | Article |
| 英文摘要 | Although attempts to synthesize divalent uranium molecules were begun three decades ago, molecular U(II) species isolable in solution have been not achieved until recent years. In 2013, Evans and co-workers synthesized the first U(II) complex, [U(Cp') (3)].[K(2,2,2-cryptand)] (Cp'= C5H4SiMe3) via flash reduction, that was suitable for X-ray crystal diffraction characterization. A year later, the group of Meyer obtained another divalent uranium complex, [U(((ArO)-Ar-Ad, Me) 3mes)].[K(2,2,2-cryptand)] employing their particularly interesting tris(aryloxide) arene ligand. The 5f(3)6d(1) and 5f(4) ground states were assigned to these two complexes, respectively, by the jointed experimental/theoretical studies. It was demonstrated that the ligand significantly affect the nature of the ground state of divalent uranium complex by tuning the energetic separation of the 5f and 6d orbitals. Therefore, careful selection of ligand makes it possible to have access to + II oxidation state of uranium and prepare new U-II complex. A flexible octadentate polypyrrollic Schiff-base macrocycle (H4L) has been developed to complex a variety of metals such as actinides, rare earth and transition metals that show a wide range of size and diverse oxidation states. Both mono-and bimetallic complexes featured with an intriguing " Pacman-like" structure were obtained. For example, the reaction of H4L with a trivalent uranium precursor [(U-III) I-3(THF)(4)] yielded a neutral [(U-IV)(L)] complex, where the uranium ion was determined by the single crystal X-ray diffraction to be situated inside the ligand mouth and held by eight nitrogen atoms together. The + IV oxidation state was assigned to the uranium by presuming dihydrogen elimination. Considering the flexibility, tetravalent-anion nature as well as capability of accommodating bimetallic ions and stabilizing various oxidation states of uranium (e.g. III similar to VI complexes have been found so far) that the polypyrrolic ligand has exhibited in previously synthesized complexes, two divalent uranium ions would be likely complexated by the ligand to generate a complex, [(U-II)(2)(L)]. In addition to enriching the coordination chemistry of U(II), it is also a good example to explore electronic structures of the low-valent uranium complex and unravel the uranium-uranium multiple bonding nature. Although many theoretical studies have explored uranium complexes, the study focusing on the divalent diuranium complex of a single macrocyclic ligand remains rare. In the work, a relativistic density functional theory has been employed to investigate [(U-II) (2)(L)]. The structures in electron spin states (singlet, triplet, quintet, septet and nonet) were optimized. Short distances of U-U (2.32 similar to 2.67 angstrom), large bond order (2.95 similar to 3.90) and high stretching vibrational frequencies (180 similar to 263 cm(-1)) were calculated. Energetic calculations find that its triplet state is the ground state. It has the electronic configuration of pi(4)sigma 2 delta(2), primarily contributed by U(5f) character. Structural and molecular-orbital analyses suggest a slightly weak uranium-uranium quadruple bond, which is confirmed by the quantum theory of atoms in molecule (QTAIM) calculations. Further comparison with analogues [(U-III) 2(L)] 2+ and [(U-IV) 2(L)] (4+) was also addressed. It is found that the uranium oxidation state is able to tune the energetic matching between the highest-energy occupied orbital of ligand and the adjacent low-energy metal-based orbital, as well as correlates with the electron transfer between metal and ligand and the diuranium multiple bond number. |
| WOS关键词 | D-BLOCK ANALOGS ; POLYPYRROLIC MACROCYCLE ; ELECTRONIC-STRUCTURE ; OXIDATION-STATE ; CHEMISTRY ; SILYLATION ; REDUCTION ; SERIES ; CM ; CL |
| WOS研究方向 | Chemistry |
| 语种 | 英语 |
| CSCD记录号 | CSCD:6015497 |
| WOS记录号 | WOS:000405655100005 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/285235]  |
| 专题 | 高能物理研究所_多学科研究中心 |
| 作者单位 | 中国科学院高能物理研究所 |
| 推荐引用方式 GB/T 7714 | Pan, QJ,Shi, WQ,Zhang, HX,et al. Structures and Uranium-Uranium Multiple Bond of Binuclear Divalent Uranium Complex of Pyrrolic Schiff-base Macrocycle: a Relativistic DFT Probe[J]. ACTA CHIMICA SINICA化学学报,2017,75(5):457-+. |
| APA | Pan, QJ.,Shi, WQ.,Zhang, HX.,Wu, QY.,吴海燕.,...&石伟群.(2017).Structures and Uranium-Uranium Multiple Bond of Binuclear Divalent Uranium Complex of Pyrrolic Schiff-base Macrocycle: a Relativistic DFT Probe.ACTA CHIMICA SINICA化学学报,75(5),457-+. |
| MLA | Pan, QJ,et al."Structures and Uranium-Uranium Multiple Bond of Binuclear Divalent Uranium Complex of Pyrrolic Schiff-base Macrocycle: a Relativistic DFT Probe".ACTA CHIMICA SINICA化学学报 75.5(2017):457-+. |
入库方式： OAI收割
来源：高能物理研究所
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