Professor Wang Shuao Leads to Significant Breakthroughs in Studies of Plutonium(V) Within a Crown Ether Inclusion Complex

Recently, Wang Shuao, from the State Key Laboratory of Radiation Medicine and Radiation Protection of Soochow University as well as Li Jun, from the Department of Chemistry, Tsinghua University and Wang Xiaolin, from the China Academy of Engineering Physics jointly carried out the first case of plutonium experimental coordination chemistry and theoretical research in China, and made a breakthrough achievement.

 

The abstract of the paper is as follows:

 

Crystalline coordination complexes of actinides, especially in atypical oxidation states, are not only fundamentally important for expanding the notably limited knowledge on the bonding nature of actinides but could also provide critical information toward the development of nuclear fuel cycle, waste management, and national security. Plutonium (Pu) is the only element in the periodic table that could exist in four oxidation states in aqueous solutions simultaneously. It represents a relatively blank gap in coordination chemistry study owing to the highly radiotoxic nature of its available isotopes and its unique position in the actinide series. Isolation of the pentavalent plutonium [Pu(V)] complex has been thought to be challenging because the highly reactive and dynamic surface redox behavior of the element, and/or the disproportionation trend of the Pu(V) state, make it thermodynamically unfavorable in aqueous solutions, which is even amplified upon strong coordination. Herein, we document a distinct Pu(V) crown ether inclusion complex, namely, PuVO2[18-crown-6]ClO4, which could be crystallized and subsequently, stabilized during a mild reduction reaction from a stock solution of Pu(VI) perchlorate. This compound was characterized fully, using X-ray crystallography and spectroscopic techniques, providing the first experimental spectroscopy data on a solid-state complex of Pu(V) with rich electronic transition information. Relativistic density functional theory (DFT) calculations confirmed the ground-state electronic configuration of Pu(V) being f3 ([core]5fδ25fФ1) and demonstrated further that a combination of cavity and steric repulsion effects assisted in the stabilization of the Pu(V) species within the 18-crown-6 ligand complex.

 

 

 PuVO2[18-crown-6]+

 

  

Stabilization of Plutonium(V) Within a Crown Ether Inclusion Complex

 

Yaxing Wang, Shu-Xian Hu, Liwei Cheng, Chengyu Liang , Xuemiao Yin , Hailong Zhang , Ao Li , Daopeng Sheng , Juan Diwu , Xiaolin Wang*, Jun Li*, Zhifang Chai, and Shuao Wang*

 

CitationCCS Chem.2020,2, 425431

 

Link to the paper:

 

https://www.chinesechemsoc.org/doi/10.31635/ccschem.020.202000152