Holmium(III) chloride is the inorganic compound with the formula HoCl3. It is a common salt but is mainly used in research. It can be used to produce pure holmium. It exhibits the same color-changing behavior seen in holmium oxide, being a yellow in natural lighting and a bright pink color in fluorescent lighting.
Preparation
The most commonly used method to obtain holmium(III) chloride involves heating a mixture of holmium(III) oxide and ammonium chloride at 200-250 °C:2
Ho2O3 + 6 NH4Cl → 2 HoCl3 + 6 NH3 + 2 H2OThe hexahydrate of holmium(III) chloride can be obtained by reaction between holmium and hydrochloric acid:3
2 Ho + 6 HCl → 2 HoCl3 + 3 H2It can also be prepared by the direct reaction between holmium and chlorine:4
2 Ho + 3 Cl2 → 2 HoCl3Properties
Holmium(III) chloride and its hexahydrate are light yellow solids in daylight that are soluble in water. The hexahydrate starts to release water of crystallization at 64 °C.5 Holmium(III) chloride has a monoclinic crystal structure analogous to that of aluminum(III) chloride.6 In the solid state it has the YCl3 layer structure.7
References
Emsley, John (2003). Nature's building blocks: an A-Z guide to the elements (Reprinted with corrections ed.). Oxford: Oxford Univ. Press. ISBN 978-0-19-850340-8. 978-0-19-850340-8 ↩
Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. ↩
Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. ↩
Webelements: Holmium http://www.webelements.com/holmium/chemistry.html ↩
Ans, Jan d'; Ans, Jan d' (1998). Elemente, anorganische Verbindungen und Materialien. Taschenbuch für Chemiker und Physiker / D'Ans (4., neubearb. u. rev. Aufl ed.). Ort nicht ermittelbar: Verlag nicht ermittelbar. ISBN 978-3-540-60035-0. 978-3-540-60035-0 ↩
Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. ↩
Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford. ISBN 0-19-855370-6 /wiki/ISBN_(identifier) ↩