Barium iodide

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Barium iodide[1]
Cotunnite structure.png
Identifiers
CAS number 13718-50-8 YesY, (anhydrous)
[7787-33-9] (dihydrate)
[13477-15-1] (hexahydrate)
PubChem 83684
ChemSpider 75507 YesY
EC number 237-276-9
Jmol-3D images Image 1
Properties
Molecular formula BaI2 (anhydrous)
BaI2·2H2O (dihydrate)
Molar mass 391.136 g/mol (anhydrous)
427.167 g/mol (dihydrate)
Appearance White orthorhombic crystals (anhydrous) colorless crystals (dihydrate)
Odor odorless
Density 5.15 g/cm3 (anhydrous)
4.916 g/cm3 (dihydrate)
Melting point 711°C (anhydrous)
decomposes at 740°C (dihydrate)
Solubility in water 166.7 g/100 mL (0 °C)
221 g/100 mL (20 °C)
246.6 g/100 mL (70 °C)
Solubility soluble in ethanol, acetone
Structure
Crystal structure Orthorhombic, oP12, SpaceGroup = Pnma, No. 62
Thermochemistry
Std enthalpy of
formation
ΔfHo298
-602.1 kJ·mol-1
Hazards
Main hazards toxic
Related compounds
Other anions barium fluoride
barium chloride
barium bromide
Other cations beryllium iodide
magnesium iodide
calcium iodide
strontium iodide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Barium iodide is an inorganic compound with the formula BaI2. The compound exists as an anhydrous and a hydrate (BaI2(H2O)2), both of which are white solids. When heated, hydrated barium iodide converts to the anhydrous salt. The hydrated form is freely soluble in water, ethanol, and acetone.

Structure[edit]

The structure of the anhydrous form resembles that of lead(II) chloride with each Ba center bound to nine iodide ligands[2] and has a crystalline packing structure that is quite similar to BaCl2.[3]

Reactions[edit]

Anhydrous BaI2 can be prepared by treating Ba metal with 1,2-diiodoethane in ether.[4]

BaI2 reacts with alkyl potassium compounds to form organobarium compounds.[5]

BaI2 can be reduced with lithium biphenyl, to give a highly active form of barium metal.[6]

Safety[edit]

Like other soluble salts of barium, barium iodide is toxic.

References[edit]

  1. ^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 4–44, ISBN 0-8493-0594-2 
  2. ^ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
  3. ^ Brackett, E. B.; Brackett, T. E.; Sass, R. L.; The Crystal Structures of Barium Chloride, Barium Bromide, and Barium Iodide. J. Phys. Chem., 1963, volume 67, 2132 – 2135
  4. ^ Duval, E.; Zoltobroda, G.; Langlois, Y.; A new preparation of BaI2: application to (Z)-enol ether synthesis. Tetrahedron Letters, 2000, 41, 337-339
  5. ^ Walter, M. D.; Wolmershauser, G.; Sitzmann, H.; Calcium, Strontium, Barium, and Ytterbium Complexes with Cyclooctatetraenyl or Cyclononatetraenyl Ligands. J. Am. Chem. Soc., 2005, 127 (49), 17494 – 17503.
  6. ^ Yanagisawa, A.; Habaue, S.; Yasue, K.; Yamamoto, H.; Allylbarium Reagents: Unprecedented Regio- and Stereoselective Allylation Reactions of Carbonyl Compounds. J. Am. Chem. Soc.1994, 116,6130-6141