Zheng Ming, Chen Fang-Yuan, Li Li, Guo Yuan-Ru, Pan Qing-Jiang
Key Laboratory of Bio-Based Material Science & Technology (Ministry of Education), College of Material Science and Engineering , Northeast Forestry University , Harbin 150040 , China.
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education), School of Chemistry and Materials Science , Heilongjiang University , Harbin 150080 , China.
Inorg Chem. 2019 Jan 7;58(1):950-959. doi: 10.1021/acs.inorgchem.8b03112. Epub 2018 Dec 14.
The reaction of (THF)(HL)(UO) (L is a tetra-anion of polypyrrolic macrocycle) with AnCp (Cp = cyclopentadienyl) afforded two intriguing cation-cation interaction (CCI) complexes (i.e., uranyl-Np and -U), but did not yield the uranyl-Pu analogue. To complement and extend experimental results, a scalar relativistic density functional theory has been performed on the formation reactions and various relevant properties of (THF)(AL)(OUO)-An(CpX) (A = Li and H; An = Pu, Np, and U; X = Me, H, Cl, and SiMe). Inspired by a strategy that improves uranyl precursor reactivity, we utilized (THF)(LiL)(UO) instead to gain a uranyl-Pu complex. Reaction free energy is reduced even to be negative (i.e., undergoing an exergonic process), which provides the thermodynamic possibility for experimental synthesis. This manner is further rationalized by the lithiated precursor showing the increased Li-O bond, uranium oxidation ability (VI → V), and exo-oxo basicity, as well as the lithiated uranyl-Pu product having more amount of electron transfer and a stronger O-Pu bond (i.e., representing the CCI). Electronic structures and electron-transfer analyses reveal a U-Pu oxidation state for the new complex. Applying the more reactive lithiated precursor also decreases the formation reaction energies of uranyl-An (An = Np and U) complexes. The second strategy via exploiting substituted Cp to raise the reactivity of the plutonium reactant does not work well.
(THF)(HL)(UO)（L 是多吡咯大环的四价阴离子）与 AnCp（Cp = 环戊二烯基）反应生成了两种有趣的阳离子-阳离子相互作用（CCI）配合物（即铀酰-镎和-铀），但未得到铀酰-钚类似物。为补充和扩展实验结果，对标量相对论密度泛函理论进行了研究，涉及(THF)(AL)(OUO)-An(CpX)（A = Li 和 H；An = Pu、Np 和 U；X = Me、H、Cl 和 SiMe）的形成反应及各种相关性质。受提高铀酰前体反应活性策略的启发，我们改用(THF)(LiL)(UO)来获得铀酰-钚配合物。反应自由能甚至降低为负值（即经历一个放能过程），这为实验合成提供了热力学可能性。锂化前体显示出增强的 Li-O 键、铀氧化能力（VI → V）和外氧碱性，以及锂化的铀酰-钚产物具有更多的电子转移量和更强的 O-Pu 键（即代表 CCI），从而进一步解释了这种方式的合理性。电子结构和电子转移分析揭示了新配合物的 U-Pu 氧化态。应用反应活性更高的锂化前体也降低了铀酰-An（An = Np 和 U）配合物的形成反应能。通过利用取代的 Cp 提高钚反应物反应活性的第二种策略效果不佳。
