lanthanum diiodide
{{Chembox
|ImageFile=LaI2.png
|Section1={{Chembox Identifiers
|CASNo=19214-98-3
| StdInChI=1S/La.2HI/h;2*1H/q+2;;/p-2
| StdInChIKey=UYZZZMCZZNTWGP-UHFFFAOYSA-L
| SMILES = [I-].[I-].[La+2]
}}
|Section2={{Chembox Properties
| Appearance= blue-black solid{{cite book | last=Holt Jr. | first=Smith L. | title=Inorganic syntheses. Volume 22 | publication-place=New York | date=1983 | isbn=978-0-470-13288-3 | oclc=86223480 |page=36}}
|La=1|I=2
|BoilingPt=
|Solubility=
}}
|Section8={{Chembox Related
|OtherCations=cerium diiodide
praseodymium diiodide
|OtherCompounds=lanthanum(III) iodide
}}
}}
Lanthanum diiodide is an iodide of lanthanum, with the chemical formula of LaI2. It is an electride, actually having a chemical formula of La3+[(I−)2e−].{{cite book | last=Holleman | first=Arnold F. | author2=Walter de Gruyter GmbH & Co. KG | title=Anorganische Chemie Band 2. Nebengruppenelemente, Lanthanoide, Actinoide, Transactinoide | publication-place=Berlin | date=2017 | isbn=978-3-11-051854-2 | oclc=968134924 | language=de |page=1789}}
Preparation
Lanthanum diiodide can be obtained from the reduction of lanthanum(III) iodide with lanthanum metal under a vacuum at 800 to 900 °C:{{cite book | last=Brauer | first=Georg | title=Handbook of Preparative Inorganic Chemistry V1. | publisher=Elsevier Science | publication-place=Burlington | date=1963 | isbn=978-0-323-16127-5 | oclc=843200092 |page=1081}}
:{{Chem2|La + 2 LaI3 -> LaI2}}
It can also be obtained by reacting lanthanum and mercury(II) iodide:
:{{Chem2|La + HgI2 -> LaI2 + Hg}}
It was first created by John D. Corbett in 1961.{{cite journal | last1=Jungmann | first1=Angelika | last2=Claessen | first2=R. | last3=Zimmermann | first3=R. | last4=Meng | first4=Ge | last5=Steiner | first5=P. | last6=Hüfner | first6=S. | last7=Tratzky | first7=S. | last8=Stöwe | first8=K. | last9=Beck | first9=H. P. | title=Photoemission of LaI2 and CeI2 | journal=Zeitschrift für Physik B | publisher=Springer Science and Business Media LLC | volume=97 | issue=1 | year=1995 | issn=0722-3277 | doi=10.1007/bf01317584 | pages=25–34| bibcode=1995ZPhyB..97...25J | s2cid=124057481 }}
Properties
Lanthanum diiodide is a blue-black solid with metallic lustre, which is easily hydrolyzed into the iodide oxide. It has a MoSi2-type structure, with the space group I4/mmm (No. 139).{{cite book | last1=Riedel | first1=Erwin | last2=Janiak | first2=Christoph | last3=Meyer | first3=Hans-Jürgen | title=Riedel, moderne anorganische Chemie | publisher=De Gruyter | publication-place=Berlin | date=2012 | isbn=978-3-11-024900-2 | oclc=781540844 | language=de |page=240}}
References
{{Lanthanum compounds}}
{{Iodides}}
{{Lanthanide halides}}