Diiodine hexaoxide, is a chemical compound of oxygen and iodine with the chemical formula I2O6. It belongs to the class of iodine oxides, and is a mixed oxide, consisting of iodine(V) and iodine(VII) oxidation states.
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| Names | |
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| Other names
iodine trioxide
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| Identifiers | |
3D model (JSmol)
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| Properties | |
| I2O6 | |
| Molar mass | 349.803 g·mol−1 |
| Appearance | yellow crust or crystals |
| Density | 4.53 g/cm3[1] |
| Melting point | 150 °C (302 °F; 423 K) (dec.) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis
editReaction of periodic acid with iodic acid in sulfuric acid:[2]
- HIO3 + H5IO6 → I2O6 + 3H2O
The thermal decomposition of meta-periodic acid in vacuum also leads to the formation of diiodine hexoxide.[2]
Chemical properties
editBelow 100 °C, diiodine hexaoxide can be stored stably in the absence of moisture. When dissolved in water, an exothermic reaction to form iodine and periodic acid takes place. When heated above 150 °C, decomposition into diiodine pentoxide can be observed:
- 2 I2O6 → 2 I2O5 + O2
The compound is diamagnetic, which is attributed to the different oxidation numbers of the iodine atoms.[2] Structurally, the compound is iodyl periodate, an iodine(V,VII) oxide approximating IO2+IO4−.[2] As a solid, the compound crystallizes in the space group P1 (space group no. 2) with the lattice constants a = 500.6 pm, b = 674.1 pm, c = 679.5 pm, α = 97.1°, β = 96.43°, γ = 105.36° with one formula unit per unit cell.[1]
See also
editReferences
edit- ^ a b Kraft, Thorsten; Jansen, Martin (1995). "Synthesis and Crystal Structure of Diiodine(V/VII) Hexaoxide: An Intermediate between a Molecular and a Polymer Solid". Journal of the American Chemical Society. 117 (25): 6795–6796. doi:10.1021/ja00130a026.
- ^ a b c d Siebert, Hans; Weise, Manfred; Woerner, Ursula (1977). "Über das Jod(V, VII)-oxid J2O6". Zeitschrift für Anorganische und Allgemeine Chemie. 432: 136–140. doi:10.1002/zaac.19774320117.
- David R. Lide (Hrsg.): CRC Handbook of Chemistry and Physics 96. Auflage. CRC Press / Taylor and Francis, Boca Raton FL, Properties of the Elements and Inorganic Compounds, S. 4-67.
- A. F. Holleman, N. Wiberg (2016). Anorganische Chemie. Grundlagen und Hauptgruppenelemente. Vol. 1. Berlin / Boston: Walter de Gruyter. p. 543. ISBN 978-3-11-049585-0.