:Titanium(III) oxide

{{chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 436822901

| ImageFile = File:Corundum struct.png

| ImageSize =

| ImageAlt = Crystal structure

| IUPACName = titanium(III) oxide

| OtherNames = titanium sesquioxide

|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 1344-54-3

| ChemSpiderID = 109727

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 134436

| EINECS = 215-697-9

| PubChem = 123111

| StdInChI = 1S/3O.2Ti

| StdInChIKey = GQUJEMVIKWQAEH-UHFFFAOYSA-N

| SMILES = O=[Ti]O[Ti]=O

}}

|Section2={{Chembox Properties

| Formula = Ti₂O₃

| MolarMass = 143.76 g/mol

| Appearance = violet black powder

| Odor = odorless

| Density = 4.49 g/cm³

| Solubility = insoluble

| MeltingPtC = 2130

| MeltingPt_notes = (decomposes)

| BoilingPt =

| MagSus = +125.6·10⁻⁶ cm³/mol

}}

| Section3 = {{Chembox Structure

| Structure_ref ={{cite journal | last=Robinson | first=William R. | title=The crystal structures of Ti2O3, a semiconductor, and (Ti0.900V0.100)2O3, a semimetal | journal=Journal of Solid State Chemistry | publisher=Elsevier BV | volume=9 | issue=3 | year=1974 | issn=0022-4596 | doi=10.1016/0022-4596(74)90082-6 | pages=255–260| bibcode=1974JSSCh...9..255R }}

| CrystalStruct = Corundum

| SpaceGroup = R{{overline|3}}c (No. 167)

| PointGroup =

| LattConst_a = 543 pm

| LattConst_b =

| LattConst_c =

| LattConst_alpha = 56.75

| LattConst_beta =

| LattConst_gamma =

| LattConst_ref =

| LattConst_Comment =

| UnitCellVolume =

| UnitCellFormulas =

| Coordination =

| MolShape =

| OrbitalHybridisation =

| Dipole =

}}

|Section7={{Chembox Hazards

| GHS_ref={{cite web |title=C&L Inventory |url=https://echa.europa.eu/information-on-chemicals/cl-inventory-database/-/discli/details/8054 |website=echa.europa.eu |access-date=12 December 2021}}

| GHSPictograms = {{GHS09}}

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|413}}

| PPhrases = {{P-phrases|}}

}}

}}

Titanium(III) oxide is the inorganic compound with the formula Ti₂O₃. A black semiconducting solid, it is prepared by reducing titanium dioxide with titanium metal at 1600 °C.{{Greenwood&Earnshaw}}

Ti₂O₃ adopts the Al₂O₃ (corundum) structure. It is reactive with oxidising agents. At around 200 °C, there is a transition from semiconducting to metallic conducting. Titanium(III) oxide occurs naturally as the extremely rare mineral in the form of tistarite.Mindat, http://www.mindat.org/min-38695.html

Other titanium(III) oxides include LiTi₂O₄ and LiTiO₂.{{cite journal |doi=10.1016/0022-3697(87)90076-X|title=A Survey of first-row ternary oxides LiMO2 (M = Sc-Cu)|year=1987|last1=Hewston|first1=T.A.|last2=Chamberland|first2=B.L.|journal=Journal of Physics and Chemistry of Solids|volume=48|issue=2|pages=97–108|bibcode=1987JPCS...48...97H}}