Lanthanum iodide

Crystal structure
	__ La 3+ __ I -
General
Surname	Lanthanum iodide
Ratio formula	LaI 2
Brief description	blue-black solid
External identifiers / databases
Wikidata	Q16832784
properties
Molar mass	392.71 g mol −1
Physical state	firmly
density	5.46 g cm −3
Melting point	830 ° C
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Lanthanum diiodide is an inorganic chemical compound of lanthanum from the group of iodides . Since it contains trivalent lanthanum and free electrons, it can also be formulated as La ³⁺ [(I ^- ) ₂ e ^- ].

Extraction and presentation

Lanthandiiodid formed by reduction of Lanthaniodid lanthanum in vacuum at 800 to 900 ° C.

{\ displaystyle \ mathrm {La + 2 \ LaI_ {3} \ longrightarrow 3 \ LaI_ {2}}}

It is also possible to produce it by reacting lanthanum with mercury (II) iodide .

{\ displaystyle \ mathrm {La + HgI_ {2} \ longrightarrow LaI_ {2} + Hg}}

The compound was first synthesized in 1961 by John D. Corbett.

properties

Lanthanum diiodide is an opaque, dark, compact solid with a strong gloss and a metal-like appearance and character. It is extremely hygroscopic and can only be stored and handled under carefully dried protective gas or in a high vacuum. In air, it changes into hydrates with moisture absorption , but these are unstable and more or less quickly transform into oxide iodides with the evolution of hydrogen. These processes take place much faster with water. It crystallizes in the MoSi ₂ structure type with the space group I 4 / mmm (space group no. 139) and contains trivalent lanthanum. Each La ³⁺ in this structure is surrounded by eight I ^- in a somewhat compressed cube-shaped formation. Template: room group / 139

Individual evidence

^ ^A ^b ^c Smith L. Holt: Inorganic Syntheses . John Wiley & Sons, 2009, ISBN 0-470-13288-4 , pp. 36 ( limited preview in Google Book search).
↑ ^a ^b ^c ^d Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 1081.
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
^ AF Holleman , N. Wiberg : Inorganische Chemie . 103rd edition. Volume 2: Subgroup elements, lanthanoids, actinides, transactinides. Walter de Gruyter, Berlin / Boston 2016, ISBN 978-3-11-049590-4 , p. 1789 (reading sample: Part C - Subgroup elements. Google book search ).
↑ Angelika Jungmann, R. Claessen, R. Zimmermann, Ge Meng, P. Steiner, S. Hüfner, S. Tratzky, K. Stöwe, HP Beck: Photoemission of LaI2 and CeI2. In: Zeitschrift für Physik B Condensed Matter. 97, 1995, pp. 25-34, doi : 10.1007 / BF01317584 .
↑ Christoph Janiak, Hans-Jürgen Meyer, Dietrich Gudat, Ralf Alsfasser: Riedel Modern Inorganic Chemistry - Christoph Janiak, Hans-Jürgen Meyer, Dietrich Gudat, Ralf Alsfasser . Walter de Gruyter, 2012, ISBN 3-11-024901-4 , p. 240 ( limited preview in Google Book search).

[Smith_L._Holt-1] A ^b ^c Smith L. Holt: Inorganic Syntheses . John Wiley & Sons, 2009, ISBN 0-470-13288-4 , pp. 36 ( limited preview in Google Book search).

[brauer-2] Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 1081.

[NV-3] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[4] AF Holleman , N. Wiberg : Inorganische Chemie . 103rd edition. Volume 2: Subgroup elements, lanthanoids, actinides, transactinides. Walter de Gruyter, Berlin / Boston 2016, ISBN 978-3-11-049590-4 , p. 1789 (reading sample: Part C - Subgroup elements. Google book search ).

[DOI10.1007/BF01317584-5] Angelika Jungmann, R. Claessen, R. Zimmermann, Ge Meng, P. Steiner, S. Hüfner, S. Tratzky, K. Stöwe, HP Beck: Photoemission of LaI2 and CeI2. In: Zeitschrift für Physik B Condensed Matter. 97, 1995, pp. 25-34, doi : 10.1007 / BF01317584 .

[Christoph_Janiak,_Hans-Jürgen_Meyer,_Dietrich_Gudat,_Ralf_Alsfasser-6] Christoph Janiak, Hans-Jürgen Meyer, Dietrich Gudat, Ralf Alsfasser: Riedel Modern Inorganic Chemistry - Christoph Janiak, Hans-Jürgen Meyer, Dietrich Gudat, Ralf Alsfasser . Walter de Gruyter, 2012, ISBN 3-11-024901-4 , p. 240 ( limited preview in Google Book search).