Indium(III) hydroxide
Chemical compound
From Wikipedia, the free encyclopedia
Indium(III) hydroxide is the chemical compound with the formula In(OH)3. Its prime use is as a precursor to indium(III) oxide, In2O3.[1] It is sometimes found as the rare mineral dzhalindite.
| Names | |
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| IUPAC name
Indium(III) hydroxide | |
| Other names
Indium hydroxide, indium trihydroxide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.039.937 |
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PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| In(OH)3 | |
| Molar mass | 165.8404 g/mol |
| Appearance | White solid |
| Density | 4.38 g/cm3 |
| Melting point | 150 °C (302 °F; 423 K) (decomposes) |
| insoluble | |
Refractive index (nD) |
1.725 |
| Structure | |
| cubic | |
| Im3 | |
| octahedral | |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Related compounds | |
Related compounds |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure
Preparation and reactions
Neutralizing a solution containing an In3+ salt such as indium nitrate (In(NO3)3) or a solution of indium trichloride (InCl3) gives a white precipitate that on aging forms indium(III) hydroxide.[4][5] A thermal decomposition of freshly prepared In(OH)3 shows the first step is the conversion of In(OH)3·xH2O to cubic indium(III) hydroxide.[4] The precipitation of indium hydroxide was a step in the separation of indium from zincblende ore by Reich and Richter, the discoverers of indium.[6]
Indium(III) hydroxide is amphoteric, like gallium(III) hydroxide (Ga(OH)3) and aluminium hydroxide (Al(OH)3), but is much less acidic than gallium hydroxide (Ga(OH)3),[5] having a lower solubility in alkaline solutions than in acid solutions.[7] It is for all intents and purposes a basic hydroxide.[8]
Dissolving indium(III) hydroxide in strong alkali gives solutions that probably contain either four coordinate [In(OH)4]− or [In(OH)4(H2O)]−.[8]
Reaction with acetic acid or carboxylic acids is likely to give the basic acetate or carboxylate salt, e.g. (CH3COO)2In(OH).[7]
At 10 MPa pressure and 250-400 °C, indium(III) hydroxide converts to indium oxide hydroxide (InO(OH)), which has a distorted rutile structure.[5]
Rapid decompression of samples of indium(III) hydroxide compressed at 34 GPa causes decomposition, yielding some indium metal.[9]
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.[10]