Holmium(III) iodide is an iodide of holmium, with the chemical formula of HoI3. It is used as a component of metal halide lamps.
Preparation
Holmium(III) iodide can be obtained by directly reacting holmium and iodine:2
2 Ho + 3 I2 → 2 HoI3Holmium(III) iodide can also be obtained via the direct reaction between holmium and mercury(II) iodide:
2 Ho + 3 HgI2 → 2 HoI3 + 3 HgThe mercury produced in the reaction can be removed by distillation.3
Holmium(III) iodide hydrate can be converted to the anhydrous form by dehydration with a large excess of ammonium iodide (since the compound is prone to hydrolysis).4
Properties
Holmium(III) iodide is a highly hygroscopic substance that dissolves in water.567 It forms yellow hexagonal crystals with a crystal structure similar to bismuth(III) iodide.8 In air, it quickly absorbs moisture and forms hydrates. The corresponding oxide iodide is also readily formed at elevated temperature.9
References
Flesch, Peter G. (2007). Light and Light Sources: High-Intensity Discharge Lamps. Springer. p. 45. ISBN 978-3540326854. 978-3540326854 ↩
Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 1077. /wiki/Georg_Brauer ↩
Asprey, L. B.; Keenan, T. K.; Kruse, F. H. (1964). "Preparation and crystal data for lanthanide and actinide triiodides". Inorganic Chemistry. 3 (8): 1137–1141. doi:10.1021/ic50018a015. https://digital.library.unt.edu/ark:/67531/metadc867868/ ↩
Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 1077. /wiki/Georg_Brauer ↩
"Holmium triiodide". WebElements. Retrieved 2022-08-20. http://www.webelements.com/compounds/holmium/holmium_triiodide.html ↩
Carl L. Yaws (2015). The Yaws Handbook of Physical Properties for Hydrocarbons and Chemicals. Gulf Professional Publishing. p. 301. ISBN 978-0128011461. Retrieved 2017-08-28. 978-0128011461 ↩
"13635 Holmium(III) iodide, ultra dry, 99.99% (REO)". Alfa Aesar. Retrieved 2022-08-20. https://www.alfa.com/en/catalog/013635 ↩
Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 1077. /wiki/Georg_Brauer ↩
Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 1077. /wiki/Georg_Brauer ↩