Europium(III) iodide

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Europium(III) iodide[1]
Names
IUPAC name
Europium(III) iodide
Other names
Europium triiodide
Identifiers
3D model (
JSmol
)
ChemSpider
ECHA InfoCard
100.033.941 Edit this at Wikidata
EC Number
  • 244-721-0
  • InChI=1S/Eu.3HI/h;3*1H/q+3;;;/p-3
    Key: OEGMUYNEEQNVBV-UHFFFAOYSA-K
  • [I-].[I-].[I-].[Eu+3]
Properties
EuI
3
Molar mass 532.677 g mol−1
Appearance colourless crystals[2]
Melting point decomposes[1]
Structure[1][3][4]
BiI3
octahedral
Related compounds
Other anions
EuF3, EuCl3, EuBr3
Other cations
SmI3, GdI3
Related compounds
EuI2
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Europium(III) iodide is an inorganic compound containing europium and iodine with the chemical formula EuI3.[1]

Preparation

Europium metal reacts directly with iodine to form europium(III) iodide:[5]

2 Eu + 3 I2 → 2 EuI3

Hydrated europium(III) iodide can be prepared dissolving europium(III) oxide or europium(III) carbonate in hydroiodic acid:[1][6]

Eu2O3 + 6 HI + 6 H2O → 2 EuI3·9H2O

Europium powder reacts with iodine in THF to form a THF adduct of europium(III) iodide:[7][8]

2 Eu + 3 I2 + 7 THF → [EuI2(THF)5][EuI4(THF)2]

The adduct can be formulated more simply as EuI3(THF)3.5.

Structure

Europium(III) iodide adopts the bismuth(III) iodide (BiI3) crystal structure type,[3][4] with octahedral coordination of each Eu3+ ion by 6 iodide ions.[1]

Reactivity

Europium(III) iodide is used as the starting material for two of the main ways of preparing europium(II) iodide:[9]

Reduction with hydrogen gas at 350 °C:

2 EuI3 + H2 → 2 EuI2 + 2 HI

Thermal decomposition[1] at 200 °C, a disproportionation reaction:

2 EuI3 → 2 EuI2 + 2 I2

Europium(III) iodide nonahydrate, EuI3·9H2O, thermally decomposes to europium(II) iodide dihydrate, EuI2·H2O.[10]

References