Barium iodide
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.
Names | |
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IUPAC name
Barium iodide | |
Other names
Barium iodide, anhydrous | |
Identifiers | |
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ChemSpider | |
ECHA InfoCard | 100.033.873 |
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Properties | |
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 (1,312 °F; 984 K) (anhydrous) decomposes at 740 °C (dihydrate) |
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 |
-124.0·10−6 cm3/mol | |
Structure | |
Orthorhombic, oP12, SpaceGroup = Pnma, No. 62 | |
Thermochemistry | |
Std enthalpy of formation (ΔfH⦵298) |
-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 otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Infobox references | |
Structure
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
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
Like other soluble salts of barium, barium iodide is toxic.
References
- Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 4–44, ISBN 0-8493-0594-2
- Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
- 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
- Duval, E.; Zoltobroda, G.; Langlois, Y.; A new preparation of BaI2: application to (Z)-enol ether synthesis. Tetrahedron Letters, 2000, 41, 337-339
- 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.
- 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