Gallium(III) sulfate

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Gallium(III) sulfate
Names
Other names
  • Digallium trisulfate
Identifiers
3D model (
JSmol
)
ChemSpider
EC Number
  • (anhydrous): 236-816-0
  • InChI=1S/2Ga.3H2O4S/c;;3*1-5(2,3)4/h;;3*(H2,1,2,3,4)/q2*+3;;;/p-6
    Key: UXLRWZBQRAWBQA-UHFFFAOYSA-H
  • (octadecahydrate): InChI=1S/2Ga.3H2O4S.18H2O/c;;3*1-5(2,3)4;;;;;;;;;;;;;;;;;;/h;;3*(H2,1,2,3,4);18*1H2/q2*+3;;;;;;;;;;;;;;;;;;;;;/p-6
    Key: RBIKSELZKJNPFC-UHFFFAOYSA-H
  • (anhydrous): [O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[Ga+3].[Ga+3]
  • (monohydrate): O.[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[Ga+3].[Ga+3]
  • (octadecahydrate): O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[Ga+3].[Ga+3]
Properties
Ga2(SO4)3
Molar mass 445.7 g/mol
Appearance White solid[1]
Density 3.86 g/cm3[2]
Melting point 680 °C (1,256 °F; 953 K)[1] (decomposes)
Slightly soluble[2]
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H315, H319, H335
P302+P352, P305+P351+P338
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
0
0
1
Related compounds
Other cations
Aluminium sulfate, Indium(III) sulfate,
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Gallium(III) sulfate refers to the

anhydrate Ga2(SO4)3 above 150 °C[3] and completely above 310 °C.[1] Anhydrous Ga2(SO4)3 is isostructural with iron(III) sulfate, crystallizing in the rhombohedral space group R3.[4]

Preparation

Gallium(III) sulfate is prepared from the reaction of hydroxygallium diacetate and sulfuric acid. The two reactants were mixed at 90 °C and left for 2 days which produced the octadecahydrate. Then, it was dried in a vacuum for 2 hours which created the extremely hygroscopic anhydrous form. The overall reaction is below:

2 Ga(CH3COO)2OH + 3 H2SO4 → Ga2(SO4)3 + 4 CH3COOH + 2 H2O

After the production, it was confirmed to be the simple salt, Ga2(SO4)3, by

x-ray diffraction.[1]

Properties

When heated over 680 °C, gallium sulfate gives off sulfur trioxide, yielding gallium(III) oxide.[1] A gallium sulfate solution in water mixed with zinc sulfate can precipitate ZnGa2O4.[5]

Derivatives

Basic gallium sulfate is known with the formula (H3O)Ga3(SO4)2(OH)6.[6]

Double gallium sulfates are known with composition NaGa3(SO4)2(OH)6, KGa3(SO4)2(OH)6, RbGa3(SO4)2(OH)6, NH4Ga3(SO4)2(OH)6. These compounds are isostructural with jarosite and alunite. Jarosite and alunite can contain a small amount of gallium substituted for iron or aluminium.[6] Organic base double gallium sulfates can contain different core structures, these can be chains of [Ga(SO4)3]3-, [Ga(OH)(SO4)2]2- or [Ga(H2O)2(SO4)2] or sheets of [Ga(H2O)2(SO4)2] units.[7]

formula mw crystal
system
space
group
unit cell Å volume density properties reference
(H3O)Ga3(SO4)2(OH)6 R3m a=7.18 c=17.17 z=1.5 766 [8]
Ga4(OH)10SO4 [9]
NH4Ga3(SO4)2(OH)6 [7]
trisodium gallium sulfate Na3Ga(SO4)3 tetragonal a = 9.451 c = 7.097 [10]
NaGa3(SO4)2(OH)6 [7]
KGa3(SO4)2(OH)6 [7]
RbGa3(SO4)2(OH)6 [7]
Caesium gallium sulfate dodecahydrate CsGa(SO4)2•12H2O cubic Pa3 Z=4 2.127 refractive index=1.461 [11]
dimethylammonium gallium sulfate hexahydrate (CH3)2NH2Ga(SO4)2·6H2O ferroeelastic [12][13]
guanidinium gallium sulfate [C(NH2)3]Ga(SO4)2·6H2O hexagonal P31m a=11.82 c=9.13 ferroelectric [14]
Ethylenediammonium acid gallium sulfate [C2H10N2][H3O][Ga(SO4)3] [7]
Ethylenediammonium basic gallium sulfate [C2H10N2][Ga(OH)(SO4)2]·H2O [7]
Tetramethylenediammonium gallium sulfate [C4H14N2][Ga(H2O)2(SO4)2]2 [7]
Hexamethylenediammonium gallium sulfate [C6H18N2][Ga(H2O)2(SO4)2]2 [7]

References