DFT Study on the Complexes in Water

Keunhong Jeong Korea Military Academy, 574, Hwarang-ro, Nowon-gu, Seoul, Republic of Korea [email protected]

1. Introduction

Nuclear power industries are on the concern over the management of irradiating nuclear fuels in long- term safety assessment of the waste management. Liquid waste from the radioactive waste management contains highly toxic including , , and which are needed to be extracted thoroughly before contaminating the nature and environment. Research has been focused on the fate of various radioactive actinides in environmental chemistry in order to manage and remediate Fig. 1. Optimized half sandwich structures of Yb(III)- C (C ). contaminated sites [1, 2]. Since most experimental 7 8 researches with those actinides have technical 2.2 Pu(III) and Pu(IV) Chloro Complexes difficulties in dealing with, theoretical researches have been considered as the supporting and/or To understand the structures of Pu(III) and Pu(IV) alternative methods for understanding the actinide in molten salt, quantum calculations on the chemistry in conjunction with exponentially plutonium chloro complexes were performed. increasing calculation capacity despite its relatively Moreover, the NPA and QTAIM studies were initial stage of study [3]. harnessed for unveiling the electron structure of the Especially, density functional theory (DFT) study complexes, which provide the electronic properties in can provide valuable information on the molecular bonding and NMR characteristics [6]. level structure, investigating the various properties of molecules, and even designing new organic ligands for actinide detection or extraction [4]. Herein, I will introduce several interesting theoretical results with several actinide complexes.

2. Quantum Calculation on Actinides

2.1 Half-sandwich Structure With Yb

After synthesizing uranocene, several actinides and with sandwich and half-sandwich structures have been highlighted in the heavy metal ion structure study[5]. After theoretical investigating Fig. 2. Optimized structures of Pu(III, IV) chloro several heavy metal ion- ligand complexes including complexes. Yb(III)-C7(C8) stable half sandwich, several interesting structural properties were successfully analyzed.

᫵᧞Ḳ 391ྙם ⫬ǎႊᔍᖒ⠱ʑྜྷ⦺⫭ ⇹ĥ⦺ᚁݡ⦽ 2019 2.3 Hydrolyzed Pu(III) and Pu(IV) Complexes

Plutonium chlorides in pyroprocessing molten salt can be hydrolyzed by water. Early detection and monitoring those reactions are highly important not only because of safety requirements but also because of its environmental issues. Therefore, possible reaction products from Pu(III)/Pu(IV) chlorides by water were investigated by DFT study.

Fig. 5. Theoretically relaxed structures of Am(III)-Ox complexes in water.

3. Conclusion

Herein, theoretical studies were performed on Fig. 3. Theoretically studied structures of hydrolyzed various actinide complex structures. The analyses Pu(III, IV) chloro complexes. after extensive quantum calculations can provide valuable information both for confirming the 2.4 U(IV)-PNPP Complex in Water experimental data and predicting the properties of actinides before/after the experiments. The DFT study on the complexation between U(IV) and PNPP was carried out in order to investigate REFERENCES important chemical properties of the U(IV)-PNPP complex in water including their stable structures, [1] J. Serp, R. J. M. Konings, R. Malmbeck, J. spin state, and infrared spectra. Rebizant, C. Scheppler, J. P. Glatz, ³(OHFWURFKHPLFDO 0HDVXUHPHQW RI 'LIIXVLRQ Coefficient of Pu LQ /LTXLG&G´, Journal of The Electrochemical Society, 561, 143±148. (2004). [2] S. E. Bonea, J. J. Dynes, J. Cliffc, and J. R. %DUJDU  ³8UDQLXP ,9  DGVRUSWLRQ E\ QDWXUDO organic matter in DQR[LFVHGLPHQWV´3URFHHGLQJV of the National Academy of Sciences of the United States of America, 114(4),711-716 (2017). [3] K. Maher, J. R. Bargar, and G. E. Brown Jr,

³(QYLURQPHQWDO 6SHFLDWLRQ RI $FWLQLGHV´, Fig. 4. Optimized structures of U(IV)-PNPP complex in Inorganic Chemistry, 52(7), 3510-3532 (2013). water and energies of possible spin states in each complex. [4] Z. Wang|, N. Pu, Y. Tian, C. Xu, F. Wang, Y. Liu, L. Zhang, J. Chen, and S. Ding, ³+LJKO\ 6HOHFWLYH 2.5 Am(III)-Oxalate Complex in Water Separation of Actinides from Lanthanides by Dithiophosphinic Acids: An in-Depth Investigation Structures and bonding properties Am(III)-Oxalate RQ([WUDFWLRQ&RPSOH[DWLRQDQG')7&DOFXODWLRQV´, complex were predicted by DFT calculations and Inorganic Chemistry, in press (ASAP) (2019). several thermodynamic properties were analyzed. [5] J. Jiang and D. .31J³$'HFDGH-RXUQH\LQ

the Chemistry of Sandwich-7\SH 7HWUDS\UURODWRí 5DUH (DUWK &RPSOH[HV´ Accounts of Chemical Research, 42(1), 79±88 (2009). [6] K. Jeong, S. M. Woo, S. %DH³')7VWXG\RQWKH bonding properties of Pu (III) and Pu (IV) chloro FRPSOH[HV´ -RXUQDO RI 1XFOHDU 6FLHQFH DQG Technology, 55(4), 424±428 (2018).

᫵᧞Ḳྙם ⫬ǎႊᔍᖒ⠱ʑྜྷ⦺⫭ ⇹ĥ⦺ᚁݡ⦽ 2019 392