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|Section2= |Section7= |Section8= }} Cobalt(II) iodide or cobaltous iodide is the inorganic compound composed with the formula CoI2. The two forms of CoI2 and the hexahydrate CoI2(H2O)6 are the principal iodides of cobalt.〔 ==Synthesis and structure== Cobalt(II) iodide is prepared by treating cobalt powder with gaseous hydrogen iodide.〔 The hydrated form (CoI2(H2O)6) can be prepared by the reaction of cobalt(II) oxide (or relate cobalt compounds) with hydroiodic acid. Cobalt(II) iodide crystallizes in two polymorphs, the α- and β-forms. The α-polymorph consists of black hexagonal crystals which turn dark green when exposed to air. Heating samples of α-CoI2 under a vacuum at 500 C causes sublimation, yielding the β-polymorph is a yellow crystals. β-CoI2 also readily absorbs moisture from the air, converting into green droplets. Upon heating to 400 °C, β-CoI2 converts to the α-form.〔O. Glemser "Cobalt, Nickel" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1518.〕 The hexaaquo salt consists of separated ()2+ and iodide ions as verified crystallographically.〔“Structure Cristalline et Expansion Thermique de L’Iodure de Nickel Hexahydrate“ (Crystal structure and thermal expansion of nickel(II) iodide hexahydrate) Louër, Michele; Grandjean, Daniel; Weigel, Dominique Journal of Solid State Chemistry (1973), 7(2), 222-8. 〕〔"The crystal structure of the crystalline hydrates of transition metal salts. The structure of CoI2·6H2O" Shchukarev, S. A.; Stroganov, E. V.; Andreev, S. N.; Purvinskii, O. F. Zhurnal Strukturnoi Khimii 1963, vol. 4, pp. 63-6.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cobalt(II) iodide」の詳細全文を読む スポンサード リンク
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