Talk:Uranyl carbonate

Oxidation-state confusions

The article has long stated that the core is uranium(VI), which is consistent with the core "UO₂" being a +2 ion and also consistent with a 1:1 ratio to the carbonate –2 ion. However, that "dioxide uranyl core" is linked to Uranium dioxide, which is the neutral UO₂ (i.e., uranium(VI)) not uranium(VI). Should it point to Uranium trioxide instead? Unless the point is that it has the same oxo-ligand count in the solid state? But the given O#U#O (where # is a triple bond) component does not match the tetrahedral lattice given in the uranium dioxide article.

Then there is a list of several forms found in ground water, including some with hydroxyl ligands. Hydroxide is usually considered a –1 ligand according to hydroxide itself (and consistent with the metal oxidation states in the minerals listed there that I spot-checked). But the article here lists "UO₂(OH)₂⁺, which would be U(VII)? Otherwise, wouldn't adding two OH^–1 to UO₂⁺² make it neutral not +1 (or else OH needs to be effectively a –½)? Or is this actually a hydrate of the uranyl-oxide or somehow else not the same form of the oxo ligands as in the parent compound? UO₂(CO₃)(OH)₃⁻ is similarly confusing. If 'uranium carbonate" as given previously is neutral, three OH^–1 to it wouldn't make it a monoanion. And even if I have no idea really how the OH behaves in the first one, adding one more of them and a –2 carbonate would only work in this second case if the OH were effectively –0. There's either something wrong with the charges or the way the ligands are identified, or else a very clear explanation is needed to unconfuse a world of non-minerologists. DMacks (talk) 05:17, 26 February 2012 (UTC)