Tellurium tetraiodide
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Other names
tellurium(IV) iodide
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Identifiers | |
3D model (
JSmol ) |
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ChemSpider | |
ECHA InfoCard
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100.029.282 |
EC Number |
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PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
TeI4 | |
Molar mass | 635.218 g/mol |
Appearance | black crystals |
Density | 5.05 g/cm3, solid |
Melting point | 280 °C (536 °F; 553 K) |
Structure | |
orthorhombic | |
Hazards | |
GHS labelling:[1] | |
Danger | |
H302, H312, H314, H332 | |
P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P322, P330, P363, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Tellurium tetraiodide (
Preparation
Tellurium tetraiodide can be prepared by reacting Te and iodomethane, CH3I.[2] In the vapour TeI4 dissociates:[3]
- TeI4 → TeI2 + I2
It can be also obtained by reacting telluric acid with hydrogen iodide.[4]
- Te(OH)6 + HI → TeI4 + I2 + 6 H2O
It can also be obtained by reacting the elements, which can also produce tellurium diiodide and tellurium monoiodide, depending on the reaction conditions:[5]
- Te + 2 I2 → TeI4
- TeI4 → TeI2 + I2
Properties
Tellurium tetraiodide is an iron-gray solid that decomposes slowly in cold water and quickly in warm water to form
Tellurium tetraiodide is a conductor when molten, dissociating into the ions TeI3+ and I−. In solvents with donor properties such as acetonitrile, CH3CN ionic complexes are formed which make the solution conducting:[3]
- TeI4 + 2 CH3CN → (CH3CN)2TeI3+ + I−
Five modifications of tellurium tetraiodide are known, all of which are composed of
References
- ^ "Tellurium tetraiodide". pubchem.ncbi.nlm.nih.gov. Retrieved 13 December 2021.
- ^ ISBN 978-0-08-037941-8.
- ^ ISBN 0-12-352651-5
- ^ ISBN 978-3-432-02328-1.
- ISBN 978-0-470-14538-8.
- ^ Tellurium(IV) iodide, 99% (metals basis) at AlfaAesar, accessed on 2013-12-17 (PDF) (JavaScript required).[dead link]
- ISBN 978-3-11-022567-9.