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.
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| Names | |
|---|---|
| IUPAC name
 Barium iodide  | |
| Other names
 Barium iodide, anhydrous  | |
| Identifiers | |
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3D model (JSmol)  | 
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| ChemSpider | |
| ECHA InfoCard | 100.033.873 | 
| EC Number | 
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PubChem CID  | 
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| UNII | |
CompTox Dashboard (EPA)  | 
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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 | |
| Occupational safety and health (OHS/OSH): | |
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
 
