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 The structure of the anhydrous form resembles that of lead(II) chloride with each Ba center bound to nine iodide ligandsWells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. . and has a crystalline packing structure that is quite similar to BaCl2.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
Reactions Anhydrous BaI2 can be prepared by treating Ba metal with 1,2-diiodoethane in ether.Duval, E.; Zoltobroda, G.; Langlois, Y.; A new preparation of BaI2: application to (Z)-enol ether synthesis. Tetrahedron Letters, 2000, 41, 337-339
BaI2 reacts with alkyl potassium compounds to form organobarium compounds.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.
BaI2 can be reduced with lithium biphenyl, to give a highly active form of barium metal.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
Safety Like other soluble salts of barium, barium iodide is toxic.
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