Aqueous Chemistry of Zirconium(IV) in Carbonate Media

Abstract

The interactions between carbonate ions and zirconium oxychloride are studied by potentiometry, dialysis, and 13C‐ and 17O‐NMR spectroscopy in aqueous media. The nature of the soluble carbonatohydroxo complexes depends on the proportions of hydrogencarbonate and carbonate ions in solution before the addition of zirconium oxychloride. Carbonate media lead to polynuclear entities containing no more than two complexed carbonate ions per Zr4+. The presence of hydrogencarbonate favors the formation of less condensed and more carbonated complexes such as [Zr(CO3)4]4−. The polycondensation degree of the species decreases when the number of carbonates linked per Zr4+ increases. In all complexes, the carbonate is bidentate, and the metal atoms are linked via hydroxo bridges. The complexation of carbonate with Zr4+ occurs for a total carbonate concentration higher than 0.1M. Consequently, in natural medium, the speciation of this metal is governed only by the formation of hydroxo complexes.

Zirconium immune-complexes for PET molecular imaging: Current status and prospects

“…Among these buffers, high concentrated carbonate is preferred because its tendency to form soluble complexes with zirconium can prevent metal precipitation, thus increasing the amount of 89 Zr 4+ available in solution for radiolabeling. However, the concentration must be controlled and the solution should not exceed pH 9, to avoid the formation of insoluble mixed carbonate hydroxide complexes [95] When 89 Zr(Ox)2 solutions are used as the starting material for the radiosyntheses, the oxalate concentration needs to be maintained high until zirconium has been chelated to minimize the formation of polymeric species. Vosjan et al strongly recommended that the total volume of 89 Zr(Ox)2 (37-185 MBq) to be neutralized should be at least 200 μL, whenever the required activity is lower than 200 μL, oxalic acid (1 M) has to be added to reach this volume.…”

“…Although the presence of the -ray at 909 keV affects the absorbed dose, limiting the amount of activity that can be administered to patients, the total energy emitted per decay (1.26 MeV/nt) is lower than 124 I (1.3075 MeV/nt) and 86 Y (3.7956 MeV/nt). However, while 86 Y and 124 I can already be used in tandem with radiotherapeutic agents such as 90 Y and 131 I, for personalized treatment planning or real-time therapy monitoring (theranostics), the possible therapeutic counterparts of 89 Zr, such as the β-emitters 97 Zr (t1/2 ~ 16.74 h) and 95 Zr (t1/2 ~ 64.0 d), have not yet been explored.…”

Multiple Rodingitization Stages in Alkaline, Tholeiitic, and Calc-Alkaline Basaltic Dikes Intruding Exhumed Serpentinized Tethyan Mantle from Evia Island, Greece

“…During the metasomatic stage 2 and stage 3, the observed Ti depletions are attributed to the total dissolution of primary minerals such as clinopyroxene and ilmenite that resulted in removal of Ti via Ti-OHcomplexes [8,51,99,100]. Although Zr is regarded as a relatively immobile element, research studies from worldwide rodingite occurrences confirm that prevailing rodingitization can result in significant Zr enrichments, which are assigned to the presence of OHand likely of Fligands [5,101,102].…”