Indium(III) hydroxide
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| IUPACName = Indium(III) hydroxide
| OtherNames = Indium hydroxide, indium trihydroxide
|Section1={{Chembox Identifiers
| CASNo = 20661-21-6
| CASNo_Ref = {{cascite|correct|CAS}}
| ChemSpiderID = 79974
| EINECS = 243-947-7
| PubChem = 88636
| UNII = 09J170CMXV
| UNII_Ref = {{fdacite|correct|FDA}}
| InChI = 1S/In.3H2O/h;3*1H2/q+3;;;/p-3
| InChIKey = IGUXCTSQIGAGSV-UHFFFAOYSA-K
| SMILES = [OH-].[OH-].[OH-].[In+3]
}}
|Section2={{Chembox Properties
| Formula = {{chem2|In(OH)3}}
| MolarMass = 165.8404 g/mol
| Appearance = White solid
| Density = 4.38 g/cm3
| MeltingPtC = 150
| MeltingPt_notes = (decomposes)
| BoilingPt =
| Solubility = insoluble
| RefractIndex = 1.725
}}
|Section3={{Chembox Structure
| CrystalStruct = cubic
| SpaceGroup = Im3
| Coordination = octahedral
| MolShape = }}
|Section7={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt =
| NFPA-H = 2 | NFPA-F = 0 | NFPA-R = 1
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|Section9={{Chembox Related
| OtherCompounds = {{ubl|Boric acid|Aluminium hydroxide|Gallium hydroxide|Thallium(III) hydroxide}}
}}
}}
Indium(III) hydroxide is the chemical compound with the formula {{chem2|In(OH)3|auto=1}}. Its prime use is as a precursor to indium(III) oxide, {{chem2|In2O3}}.{{cite book | title = The Group 13 Metals Aluminium, Gallium, Indium and Thallium: Chemical Patterns and Peculiarities | author = Simon Aldridge, Anthony J. Downs | publisher = Wiley | date = 2011 | isbn = 978-0-470-68191-6}} It is sometimes found as the rare mineral dzhalindite.
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Structure
Indium(III) hydroxide has a cubic structure, space group Im3, a distorted rhenium trioxide structure.{{cite journal | title = Hydrothermal Investigation of the systems In2O3-H2O-Na2O and In2O3-D2O-Na2O. The crystal structure of rhombohedral In2O3 and In(OH)3 | author = A Norlund Christensen, N.C. Broch | journal = Acta Chemica Scandinavica | volume = 21 | date = 1967 | pages = 1046–1056| doi = 10.3891/acta.chem.scand.21-1046 | doi-access = free }}{{cite book | author = Wells A.F. | date = 1984 | title = Structural Inorganic Chemistry | edition = 5th | publisher = Oxford Science Publications | isbn = 0-19-855370-6 }}
Preparation and reactions
Neutralizing a solution containing an {{chem2|In(3+)}} salt such as indium nitrate ({{chem2|In(NO3)3}}) or a solution of indium trichloride ({{chem2|InCl3}}) gives a white precipitate that on aging forms indium(III) hydroxide.{{cite journal|last1=Sato|first1=T.|title=Preparation and thermal decomposition of indium hydroxide|journal=Journal of Thermal Analysis and Calorimetry|volume=82|issue=3|year=2005|pages=775–782|issn=1388-6150|doi=10.1007/s10973-005-0963-4|s2cid=195329927}}{{cite book | author = Egon Wiberg, Arnold Frederick Holleman | date = 2001 | title = Inorganic Chemistry | publisher = Elsevier | isbn = 0123526515 }} A thermal decomposition of freshly prepared {{chem2|In(OH)3}} shows the first step is the conversion of {{chem2|In(OH)3*xH2O}} to cubic indium(III) hydroxide. The precipitation of indium hydroxide was a step in the separation of indium from zincblende ore by Reich and Richter, the discoverers of indium.{{cite book | title = Advanced Inorganic Chemistry | volume = I | edition = 31st | date = 2008 | publisher = Krishna Prakashan Media | isbn = 9788187224037}}
Indium(III) hydroxide is amphoteric, like gallium(III) hydroxide ({{chem2|Ga(OH)3}}) and aluminium hydroxide ({{chem2|Al(OH)3}}), but is much less acidic than gallium hydroxide ({{chem2|Ga(OH)3}}), having a lower solubility in alkaline solutions than in acid solutions.{{cite book | title = The Aqueous Chemistry of the Elements | author = George K. Schweitzer, Lester L. Pesterfield | publisher = Oxford University Press | date= 2009 | isbn = 978-0195393354 }} It is for all intents and purposes a basic hydroxide.{{Cite book| title = Chemistry of aluminium, gallium, indium, and thallium| author = Anthony John Downs| publisher = Springer| year = 1993| isbn = 0-7514-0103-X}}
Dissolving indium(III) hydroxide in strong alkali gives solutions that probably contain either four coordinate {{chem2|[In(OH)4]−}} or {{chem2|[In(OH)4(H2O)]−}}.
Reaction with acetic acid or carboxylic acids is likely to give the basic acetate or carboxylate salt, e.g. {{chem2|(CH3COO)2In(OH)}}.
At 10 MPa pressure and 250-400 °C, indium(III) hydroxide converts to indium oxide hydroxide (InO(OH)), which has a distorted rutile structure.
Rapid decompression of samples of indium(III) hydroxide compressed at 34 GPa causes decomposition, yielding some indium metal.{{cite journal|last1=Gurlo|first1=Aleksander|last2=Dzivenko|first2=Dmytro|last3=Andrade|first3=Miria|last4=Riedel|first4=Ralf|last5=Lauterbach|first5=Stefan|last6=Kleebe|first6=Hans-Joachim|title=Pressure-Induced Decomposition of Indium Hydroxide|journal=Journal of the American Chemical Society|volume=132|issue=36|year=2010|pages=12674–12678|issn=0002-7863|doi=10.1021/ja104278p|pmid=20731389}}
Laser ablation of indium(III) hydroxide gives indium(I) hydroxide (InOH), a bent molecule with an In-O-H angle of around 132° and an In-O bond length of 201.7 pm.{{cite journal|last1=Lakin|first1=Nicholas M.|last2=Varberg|first2=Thomas D.|last3=Brown|first3=John M.|title=The Detection of Lines in the Microwave Spectrum of Indium Hydroxide, InOH, and Its Isotopomers|journal=Journal of Molecular Spectroscopy|volume=183|issue=1|year=1997|pages=34–41|issn=0022-2852|doi=10.1006/jmsp.1996.7237|bibcode=1997JMoSp.183...34L}}
References
{{Reflist}}
{{Indium compounds}}
{{Hydroxides}}