| Names | |
|---|---|
| IUPAC name Niobium(V) 2-hydroxy-2-oxoacetate | |
| Systematic IUPAC name Niobium(V) 2-hydroxy-2-oxoethanoate | |
| Other names Niobium oxalate Niobium pentoxalate | |
| Identifiers | |
3D model (JSmol) | |
| ECHA InfoCard | 100.040.295 |
CompTox Dashboard (EPA) | |
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| Properties | |
| Nb(HC2O4)5 | |
| Molar mass | 538.056 |
| Appearance | colourless monoclinic crystals [1] |
| soluble in water | |
| Solubility | soluble in oxalic acid |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Niobium(V) oxalate is the hydrogen oxalate salt of niobium(V). The neutral salt has not been prepared. [2]
Niobium(V) can form complexes with hydroxy acids, as well as oxalic acid. The salt formed is more complex than tartaric acid for niobium (as opposed to tantalum). [3] NH4[NbO(C2O4)2(H2O)2]·3H2O starts to lose water at 125°C, and at 630°C, it fully decomposes, forming a compound known as niobium pentoxide; [4] Heating this complex and sodium citrate at 650°C can form sodium niobate (NaNbO3). [5]
Rb3[NbO(C2O4)3]·2H2O is a colourless crystal, which includes the [NbO(C2O4)3]3- anion. [6] Sr3[NbO(C2O4)3]2·8H2O is a compound containing the same anion, forming the anhydrous at 200°C, starting to decompose at 260°C, and at 875°C it decomposes to SrCO3 and SrNb2O6. [7]