Yttrium oxalate

Yttrium oxalate is an inorganic compound, a salt of yttrium and oxalic acid with the chemical formula Y₂(C₂O₄)₃.^[3] The compound does not dissolve in water and forms crystalline hydrates—colorless crystals.^[4]

Yttrium oxalate

Names
Other names Yttrium(3+) oxalate, Diyttrium trioxalate
Identifiers
CAS Number	867-68-5 Y
3D model (JSmol)	Interactive image
ChemSpider	144422
ECHA InfoCard	100.011.607
EC Number	212-767-0
PubChem CID	164745
CompTox Dashboard (EPA)	DTXSID401014690
InChI InChI=1S/3C2H2O4.H2O.2Y/c3*3-1(4)2(5)6;;;/h3*(H,3,4)(H,5,6);1H2;;/q;;;;2*+3/p-6 Key: NRMHTSMZQQFBRX-UHFFFAOYSA-H
SMILES [Y+3].[Y+3].O=C([O-])C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O
Properties
Chemical formula	Y2(C2O4)3
Molar mass	441.87
Appearance	White crystals
Solubility in water	insoluble
Solubility product (Ksp)	5.1 × 10−30.[1]
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H302+H312, H312[2]
Precautionary statements	P264, P270, P280, P301+P312, P302+P352, P312, P322, P330, P363, P501
Related compounds
Related compounds	Calcium oxalate Sodium oxalate Magnesium oxalate Strontium oxalate Barium oxalate Iron(II) oxalate Iron(III) oxalate Lithium oxalate Praseodymium 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 yttrium salts with oxalic acid:^[5]

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

Properties

Yttrium oxalate is highly insoluble in water and converts to the oxide when heated.^[6] Yttrium oxalate forms crystalline hydrates (colorless crystals) with the formula Y₂(C₂O₄)₃•n H₂O, where n = 4, 9, and 10.

Decomposes when heated:

${\displaystyle {\mathsf {Y_{2}(C_{2}O_{4})_{3}\ {\xrightarrow {700^{o}C}}\ Y_{2}O_{3}+3CO_{2}+3CO}}}$

The solubility product of yttrium oxalate at 25 °C is 5.1 × 10⁻³⁰.^[1]

The trihydrate Y₂(C₂O₄)₃•3H₂O is formed by heating more hydrated varieties at 110 °C.^[7]

Y₂(C₂O₄)₃•2H₂O, which is formed by heating the decahydrate at 210 °C) forms monoclinic crystals with unit cell dimensions a=9.3811 Å, b=11.638 Å, c=5.9726 Å, β=96.079°.^[8]

Related

Several yttrium oxalate double salts are known containing additional cations. Also a mixed-anion compound with carbonate is known.

formula	name	formula weight	crystal form	space group	unit cell Å	volume Å3	properties	references
NH4Y(C2O4)2.H2O	Ammonium yttrium oxalate monohydrate		monoclinic	P2/n	a=9.18 b=6.09 c=7.89 β=90.2 Z=2			[9]
[C6N2H16]0.5[Y(H2O)(C2O4)2]·2H2O		377.1	triclinic	P1	a = 8.229, b = 9.739, c = 9.754, α = 60.74, β = 72.36, γ = 84.67°, Z = 2	648.5	density 1.931	[10]
[C5N2H12] [Y(C2O4)2]		365.1	monoclinic	Cc	a = 11.552, b = 17.168, c = 8.719, β = 130.64°, Z = 2	1312.1	density 1.848	[10]
C5NH6Y(C2O4)2•3H2O	Pyridinium yttrium oxalate trihydrate							[11]
[Y(H2O)]Na(C2O4)2.3H2O	yttrium sodium oxalate tetrahydrate	360.005	monoclinic	Pc	a=8.623 b=8.6310 c=14.896 β=102.848 Z=4	1080.9		[12]
YK(C2O4)2.4H2O	Yttrium potassium oxalate tetrahydrate		tetragonal	I41/a	Z = 4 a = 11.4612, c = 8.9040	1169.6		[13][14]
Y(H2O)Cs(C2O4)2	Caesium yttrium oxalate monohydrate		monoclinic	P2/n	a = 8.979, b = 6.2299, c = 8.103, β = 90.05°	453.3		[15]
RbLn(C2O4)2•3H2O	Rubidium yttrium oxalate trihydrate							[16]
[Y(H2O)]2(C2O4)(CO3)2	yttrium oxalate carbonate	421.876	orthorhombic	C2221	a = 7.8177, b = 14.943, c = 9.4845, Z = 4	1108.0	density 2.526	[17]