Samarium(III) oxalate

Samarium(III) oxalate is an inorganic compound, a salt of samarium and oxalic acid with the formula Sm₂(C₂O₄)₃.^[1] The compound does not dissolve in water, forms a crystalline hydrate with yellow crystals.^[2]

Samarium(III) oxalate

Names
Other names Tris(oxalato)disamarium, Samarium oxalate,
Identifiers
CAS Number	3252-68-4 Y
3D model (JSmol)	Interactive image
ChemSpider	144736
EC Number	221-844-8
PubChem CID	165093
CompTox Dashboard (EPA)	DTXSID50920648
InChI InChI=1S/3C2H2O4.2Sm/c3*3-1(4)2(5)6;;/h3*(H,3,4)(H,5,6);;/q;;;2*+3/p-6 Key: DABIZUXUJGHLMW-UHFFFAOYSA-H
SMILES C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].C(=O)(C(=O)[O-])[O-].[Sm+3].[Sm+3]
Properties
Chemical formula	C6O12Sm2
Molar mass	564.77 g·mol−1
Appearance	Yellow crystals
Solubility in water	Insoluble
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312
Precautionary statements	P264, P270, P280, P301+P312, P302+P352, P312, P322, P330, P363, P501
Related compounds
Other cations	Cerium(III) oxalate Europium(III) oxalate Gadolinium(III) oxalate Holmium(III) oxalate Lanthanum(III) oxalate Neodymium(III) oxalate Praseodymium(III) oxalate Promethium(III) oxalate Terbium(III) oxalate Thulium(III) oxalate Ytterbium(III) oxalate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

Precipitation of soluble samarium salts with oxalic acid:^[3]

${\displaystyle {\mathsf {2SmCl_{3}+3H_{2}C_{2}O_{4}\ {\xrightarrow {}}\ Sm_{2}(C_{2}O_{4})_{3}\downarrow +6HCl}}}$

Also a reaction of samarium nitrate and oxalic acid in an aqueous solution:

${\displaystyle {\mathsf {2Sm(NO_{3})_{3}+3H_{2}C_{2}O_{4}\ \xrightarrow {} \ Sm_{2}(C_{2}O_{4})_{3}\downarrow +6HNO_{3}}}}$

Physical properties

Samarium(III) oxalate forms a crystalline hydrate of the composition Sm₂(C₂O₄)₃ • 10H₂O with yellow crystals.

Chemical properties

Decomposes on heating:^[4]

${\displaystyle {\mathsf {Sm_{2}(C_{2}O_{4})_{3}\ {\xrightarrow {800^{o}C}}\ Sm_{2}O_{3}+3CO_{2}+3CO}}}$

Crystalline hydrate Sm₂(C₂O₄)₃ • 10H₂O decomposes stepwise.^[5]