Europium(II) chloride

Europium(II) chloride is an inorganic compound with a chemical formula EuCl₂. When it is irradiated by ultraviolet light, it has bright blue fluorescence.^[3]

Europium(II) chloride

Names
Other names Europium dichloride
Identifiers
CAS Number	13769-20-5 dry Y 70442-98-7 dihydrate Y
3D model (JSmol)	Interactive image
ChemSpider	75541
ECHA InfoCard	100.033.973
EC Number	237-386-7
PubChem CID	83719
CompTox Dashboard (EPA)	DTXSID2065620
InChI InChI=1S/2ClH.Eu/h2*1H;/q;;+2/p-2 Key: BMANZYKPCBPZFG-UHFFFAOYSA-L
SMILES Cl[Eu]Cl
Properties
Chemical formula	Cl2Eu
Molar mass	222.86 g·mol−1
Appearance	white solid
Density	4.86 g·cm−3[1]
Melting point	738 °C (1,011 K)[2]
Boiling point	2,190 °C (2,460 K)[2]
Related compounds
Other anions	europium difluoride europium dibromide europium diiodide
Other cations	samarium dichloride thulium dichloride
Related compounds	europium trichloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

Europium dichloride can be produced by reducing europium trichloride with hydrogen gas at high temperature:^[4]

2 EuCl₃ + H₂ → 2 EuCl₂ + 2 HCl

If dry europium trichloride reacts with lithium borohydride in THF, it can also produce europium dichloride:^[5]

2 EuCl₃ + 2 LiBH₄ → 2 EuCl₂ + 2 LiCl + H₂↑ + B₂H₆↑

Properties

Europium dichloride can form yellow ammonia complexes:EuCl₂•8NH₃, and can dissolve to pale yellowish EuCl₂•NH₃.^[4] Europium dichloride can react with europium hydride at 120-bar H₂, producing EuClH that fluoresces green.^[6]

References

1. Roger Blachnik (Hrsg.): Taschenbuch für Chemiker und Physiker. Band III: Elemente, anorganische Verbindungen und Materialien, Minerale. begründet von Jean d’Ans, Ellen Lax. 4., neubearbeitete und revidierte Auflage. Springer, Berlin 1998, ISBN 3-540-60035-3, S. 446–447
2. Polyachenok, O. G.; Novikov, G. I. Saturated vapor pressures of SmCl2, EuCl2, YbCl2. Zhurnal Neorganicheskoi Khimii, 1963. 8 (12): 2631–2634. ISSN 0044-457X.
3. Howell, J.K.; Pytlewski, L.L. (August 1969). "Synthesis of divalent europium and ytterbium halides in liquid ammonia". Journal of the Less Common Metals. 18 (4): 437–439. doi:10.1016/0022-5088(69)90017-4.
4. Klemm, Wilhelm; Doll, Walter. Measurements on the bivalent and the quadrivalent compounds of the rare earths. VI. The halides of bivalent europium. Zeitschrift für Anorganische und Allgemeine Chemie, 1939. 241: 233–238. ISSN 0044-2313.
5. Rossmanith, K.; Muckenhuber, E. Reaction of rare earth chlorides with lithium borohydride. II. Monatshefte fuer Chemie, 1961. 92: 600–604. ISSN 0026-9247.
6. Kunkel, Nathalie; Rudolph, Daniel; Meijerink, Andries; Rommel, Stefan; Weihrich, Richard; Kohlmann, Holger; Schleid, Thomas (2015). "Green Luminescence of Divalent Europium in the Hydride Chloride EuHCl". Zeitschrift für anorganische und allgemeine Chemie. 641 (7): 1220–1224. doi:10.1002/zaac.201400531. ISSN 0044-2313.