Neptunium(IV) oxalate

Neptunium(IV) oxalate^[1] is an inorganic compound, a salt of neptunium and oxalic acid with the chemical formula Np(C₂O₄)₂.^[2] The compound is slightly soluble in water, forms crystalline hydrates—green crystals.^[3][4]

Neptunium(IV) oxalate

Identifiers
CAS Number	20196-48-9 Y
3D model (JSmol)	Interactive image
CompTox Dashboard (EPA)	DTXSID101336972
InChI InChI=1S/2C2H2O4.Np/c2*3-1(4)2(5)6;/h2*(H,3,4)(H,5,6);/q;;+4/p-4 Key: KBWUHCITSWHCDN-UHFFFAOYSA-J
SMILES C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].[Np+4]
Properties
Chemical formula	Np(C2O4)2
Molar mass	413.04
Appearance	Green crystals
Solubility in water	slightly soluble
Hazards
GHS labelling:
Signal word	Danger
Related compounds
Related compounds	Thorium oxalate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

Neptunium(IV) oxalate is formed by the oxalic acid precipitation of neptunium (IV) solutions:^[5]

NpCl₄ + 2H₂C₂O₄ → Np(C₂O₄)₂·6H₂O↓ + 4HCl

Physical properties

Neptunium(IV) oxalate forms a crystalline hydrate of the composition Np(C₂O₄)₂·6H₂O with green crystals.

It is insoluble in acetone, and slightly soluble in water.^[6]

Chemical properties

Neptunium(IV) oxalate decomposes on heating:^[7]

${\displaystyle {\mathsf {Np(C_{2}O_{4})_{2}\ {\xrightarrow {400^{o}C}}\ NpO_{2}+2CO_{2}+2CO}}}$

Applications

Neptunium(IV) oxalate is used as an intermediate product in the purification of neptunium.^[8][9]