caesium triiodide

{{Chembox

| Name =

| ImageFileL1 = Caesium-triiodide-xtal-3D-SF.png

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| ImageFileR1 = Caesium-triiodide-unit-cell-3D-balls.png

| ImageFile2 = Sample_of_caesium_triiodide.jpg

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| Section1 = {{Chembox Identifiers

| CASNo = 12297-72-2

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

| ChemSpiderID = 13753323

| EC_number = 625-701-4

| PubChem = 23717889

| StdInChI=1S/Cs.I3/c;1-3-2/q+1;-1

| StdInChIKey = PSDVEXXHXQVSQT-UHFFFAOYSA-N

| SMILES = I[I-]I.[Cs+]

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| Section2 = {{Chembox Properties

| Cs=1 | I=3

| Appearance = purple{{cite book | author = Ronald Rich | date = 22 December 2007 | title = Inorganic Reactions in Water | publisher = Springer | pages = 472 | isbn = 978-3-540-73962-3 | url = https://books.google.com/books?id=Dv_F03cdKPUC&pg=PA472 | access-date = 2022-09-12 | archive-date = 2022-09-12 | archive-url = https://web.archive.org/web/20220912164217/https://books.google.com/books?id=Dv_F03cdKPUC&pg=PA472 | url-status=live }}

| Density =

| MeltingPt = 77 °C (decomposes){{cite journal|journal=Polyhedron|volume=1|issue=2|language=en|date=Jan 1982|pages=215–216|doi=10.1016/S0277-5387(00)80991-2|url=https://linkinghub.elsevier.com/retrieve/pii/S0277538700809912|title=Thermogravimetric analysis and dissociation pressure of caesium tribalides|accessdate=2022-09-09|author=G.S. Harris, J.S. McKechnie|archive-date=2018-06-09|archive-url=https://web.archive.org/web/20180609103540/https://linkinghub.elsevier.com/retrieve/pii/S0277538700809912|url-status=live|url-access=subscription}}

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| Section3 = {{Chembox Hazards

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Caesium triiodide is an inorganic compound, with the chemical formula of CsI₃. It can be prepared by slow volatilization and crystallization of caesium iodide and iodine in aqueous ethanol solution.{{cite journal|journal=Journal of the American Chemical Society|volume=47|issue=6|language=en|issn=0002-7863|date=Jun 1925|pages=1561–1571|doi=10.1021/ja01683a009|url=https://pubs.acs.org/doi/abs/10.1021/ja01683a009|accessdate=2022-09-09|author=Richard M. Bozorth, Linus Pauling|title=The Crystal Structures of Cesium Tri-Iodide and Cesium Dibromo-Iodide |archive-date=2022-09-09|archive-url=https://web.archive.org/web/20220909080113/https://pubs.acs.org/doi/abs/10.1021/ja01683a009|url-status=live|url-access=subscription}} It can form precipitates with diazobenzene.{{cite journal|journal=Journal of the Chemical Society (Resumed)|language=en|issn=0368-1769|date=1960|pages=4603–4608|doi=10.1039/jr9600004603|url=http://xlink.rsc.org/?DOI=jr9600004603|title=891. The reaction of the benzenediazonium ion with certain anions in aqueous acid solution|accessdate=2022-09-09|author=H. F. Halliwell, S. C. Nyburg|url-access=subscription}}

It undergoes a phase transition from Pnma to P-3c1 under high pressure, and its structure changes from layered to 3D.{{cite journal|journal=Inorganic Chemistry|volume=61|issue=28|language=en|issn=0020-1669|date=2022-07-18|pages=10977–10985|doi=10.1021/acs.inorgchem.2c01690|url=https://pubs.acs.org/doi/10.1021/acs.inorgchem.2c01690|title=Investigating the Structural Symmetrization of CsI 3 at High Pressures through Combined X-ray Diffraction Experiments and Theoretical Analysis|accessdate=2022-09-09|author=Tomasz Porȩba, Stefano Racioppi, Gaston Garbarino, Wolfgang Morgenroth, Mohamed Mezouar|pmid=35792580 |s2cid=250313558 |archive-date=2022-09-09|archive-url=https://web.archive.org/web/20220909080852/https://pubs.acs.org/doi/10.1021/acs.inorgchem.2c01690|url-status=live|url-access=subscription}}