Indium(III) hydroxide is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the formula In(OH)₃. Its prime use is as a precursor to indium(III) oxide, In₂O₃. It is sometimes found as the rare mineral dzhalindite.

Structure

Indium(III) hydroxide has a cubic structure, space group Im3, a distorted ReO₃ structure.

Preparation and reactions

Neutralizing a solution containing an In³⁺ salt such as indium nitrate (In(NO₃)₃) or a solution of

indium trichloride Indium(III) chloride is the chemical compound with the formula In Cl3. This salt is a white, flaky solid with applications in organic synthesis as a Lewis acid. It is also the most available soluble derivative of indium. Synthesis and structur ...

(InCl₃) gives a white precipitate that on aging forms indium(III) hydroxide. A

thermal decomposition Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes. The reaction is usually endothermic as heat is re ...

of freshly prepared In(OH)₃ shows the first step is the conversion of In(OH)₃xH₂O to cubic indium(III) hydroxide. The precipitation of indium hydroxide was a step in the separation of indium from

zincblende Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Va ...

ore by

Reich ''Reich'' (; ) is a German noun whose meaning is analogous to the meaning of the English word "realm"; this is not to be confused with the German adjective "reich" which means "rich". The terms ' (literally the "realm of an emperor") and ' (lit ...

and Richter, the discoverers of indium. Indium(III) hydroxide is

amphoteric In chemistry, an amphoteric compound () is a molecule or ion that can react both as an acid and as a base. What exactly this can mean depends on which definitions of acids and bases are being used. One type of amphoteric species are amphipro ...

, like

gallium(III) hydroxide Gallium hydroxide, Ga(OH)3 is formed as a gel following the addition of ammonia to Ga3+ salts.Anthony John Downs, (1993), ''Chemistry of Aluminium, Gallium, Indium, and Thallium'', Springer, It is also found in nature as the rare mineral söhngei ...

(Ga(OH)₃) and

aluminium hydroxide Aluminium hydroxide, Al(OH)3, is found in nature as the mineral gibbsite (also known as hydrargillite) and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium hydroxide is amphoteric, i.e., it has both basic an ...

(Al(OH)₃), but is much less acidic than gallium hydroxide (Ga(OH)₃), having a lower solubility in alkaline solutions than in acid solutions. It is for all intents and purposes a basic hydroxide. Dissolving indium(III) hydroxide in strong alkali gives solutions that probably contain either four coordinate In(OH)₄⁻ or In(OH)₄(H₂O)⁻. Reaction with acetic acid or carboxylic acids is likely to give the basic acetate or carboxylate salt, e.g. In(OH)(OOCCH₃)₂. 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. 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.

References

{{Hydroxides Indium compounds Hydroxides Inorganic compounds