Fellhauer David, Lee Jun-Yeop, DiBlasi Nicole A, Walter Olaf, Gaona Xavier, Schild Dieter, Altmaier Marcus
Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology, P.O. Box 3640, 76021 Karlsruhe, Germany.
School of Mechanical Engineering, Pusan National University, 2, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 46241, South Korea.
J Am Chem Soc. 2022 Jun 1;144(21):9217-9221. doi: 10.1021/jacs.2c03479. Epub 2022 May 19.
The ternary neptunium(V) (Np(V)) hydroxides Na[NpO(OH)]·0.5HO and Na[NpO(OH)] were synthesized in aqueous NaOH solutions at = 80 °C, and their crystal structures were determined to be monoclinic, 2, = 2, = 5.9859(2), = 10.1932(3), = 12.1524(4) Å, β = 98.864(1)°, = 732.63(4) Å for and orthorhombic, 222, = 4, = 5.856(7), = 7.621(9), = 8.174(9) Å, = 364.8(7) Å for . By combining the detailed structural information with results from systematic solubility investigations, a comprehensive chemical and thermodynamic model of the Np(V) behavior in NaCl-NaOH solutions was evaluated. The results reveal a great stability of the ternary Na-Np(V)-OH solid phases that significantly enhances the predominance field of the entire Np(V) redox state to high alkalinity.
在80°C的NaOH水溶液中合成了三元镎(V)(Np(V))氢氧化物Na[NpO(OH)]·0.5H₂O和Na[NpO(OH)]，并确定它们的晶体结构为单斜晶系，空间群P2₁/c，a = 2，b = 2，c = 5.9859(2) Å，β = 98.864(1)°，V = 732.63(4) ų ；以及正交晶系，空间群P2₂2₂，a = 4，b = 5.856(7) Å，c = 7.621(9) Å，V = 364.8(7) ų 。通过将详细的结构信息与系统溶解度研究结果相结合，评估了Np(V)在NaCl-NaOH溶液中行为的综合化学和热力学模型。结果表明，三元Na-Np(V)-OH固相具有很高的稳定性，这显著增强了整个Np(V)氧化还原态在高碱度下的优势区域。
