As the crucial soluble species of long-lived radionuclides 1291 and 79Se, iodate and selenite anions commonly share similar geometry of the trigonal pyramid XO3 (X = I, Se) but in different valence states. Although large amounts of investigations have been performed aiming at understanding the environmental behavior of these two anions individually, studies on cases when they coexist are extremely scarce. Structurally well-characterized natural/synthetic crystalline solids simultaneously incorporating these two anions as potential solubility-limiting products at the nuclear waste geological depository remain elusive. We report here a crystalline solid Th(IO3)(2)(Seo(3)) representing the first example of aliovalent substitution between IO3- and SeO32- sharing the same structural site, as demonstrated by single crystal X-ray diffraction, laser-ablation inductively coupled plasma mass spectrometry analysis, and spectroscopic techniques including infrared, Raman, and X-ray absorption spectroscopies. Sequentially, in the Eu(IO3)(3) solid matrix, we demonstrated that the IO3- site can be sufficiently substituted by SeO32- in the presence of Th4+ via simultaneous incorporation of Th4+ and SeO32- in a charge-balancing mechanism The obtained results provide insights into the environmental behavior of fission products Se-79 and I-129: they may cocrystallize in one solid matrix and may be efficiently immobilized by incorporation into each other's solid phase through solid solution.
Substitutional Disorder of SeO32-_IO3- in the Crystalline Solid Matrix_ Insights into the Fate of Radionuclides Se-79 and I-129 in the Environment.pdf（2243KB）
Wang, YX,Wang, YM,Zhang, LJ,et al. Substitutional Disorder of SeO32-/IO3- in the Crystalline Solid Matrix: Insights into the Fate of Radionuclides Se-79 and I-129 in the Environment[J]. INORGANIC CHEMISTRY,2017-01-01,56(6):3702-3708.
