Tellurium tetraiodide

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Tellurium tetraiodide
Te4I16.png
Names
Other names
tellurium(IV) iodide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.282 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 232-210-5
PubChem CID
UNII
  • InChI=1S/I4Te/c1-5(2,3)4
    Key: XCOKHDCPVWVFKS-UHFFFAOYSA-N
  • [Te](I)(I)(I)I
Properties
TeI4
Molar mass 635.218 g/mol
Appearanceblack crystals
Density 5.05 g/cm3, solid
Melting point 280 °C (536 °F; 553 K)
Structure
orthorhombic
Hazards
GHS labelling: [1]
GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
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 (Te I4) is an inorganic chemical compound. It has a tetrameric structure which is different from the tetrameric solid forms of TeCl4 and TeBr4. [2] In TeI4 the Te atoms are octahedrally coordinated and edges of the octahedra are shared. [2]

Contents

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 dioxide and hydrogen iodide. [6] It is stable even in moist air and decomposes when heated, releasing iodine. It is soluble in hydriodic acid to form H[TeI5] and it is slightly soluble in acetone. [4]

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 tetrameric molecules. [7] The δ form is the most thermodynamically stable form. This is structurally derived (as well as the α, β and γ forms) from the ε form.

Related Research Articles

<span class="mw-page-title-main">Iodine</span> Chemical element, symbol I and atomic number 53

Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at 114 °C (237 °F), and boils to a violet gas at 184 °C (363 °F). The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek Ιώδης 'violet-coloured'.

<span class="mw-page-title-main">Titanium tetraiodide</span> Chemical compound

Titanium tetraiodide is an inorganic compound with the formula TiI4. It is a black volatile solid, first reported by Rudolph Weber in 1863. It is an intermediate in the van Arkel–de Boer process for the purification of titanium.

<span class="mw-page-title-main">Tellurium tetrabromide</span> Chemical compound

Tellurium tetrabromide (TeBr4) is an inorganic chemical compound. It has a similar tetrameric structure to TeCl4. It can be made by reacting bromine and tellurium. In the vapour TeBr4 dissociates:

Iodine can form compounds using multiple oxidation states. Iodine is quite reactive, but it is much less reactive than the other halogens. For example, while chlorine gas will halogenate carbon monoxide, nitric oxide, and sulfur dioxide, iodine will not do so. Furthermore, iodination of metals tends to result in lower oxidation states than chlorination or bromination; for example, rhenium metal reacts with chlorine to form rhenium hexachloride, but with bromine it forms only rhenium pentabromide and iodine can achieve only rhenium tetraiodide. By the same token, however, since iodine has the lowest ionisation energy among the halogens and is the most easily oxidised of them, it has a more significant cationic chemistry and its higher oxidation states are rather more stable than those of bromine and chlorine, for example in iodine heptafluoride.

Germanium iodides are inorganic compound with the formula GeIx. Two such compounds exist: germanium(II) iodide, GeI2, and germanium(IV) iodide GeI4.

<span class="mw-page-title-main">Rubidium iodide</span> Chemical compound

Rubidium iodide is a salt of rubidium and iodine, with the chemical formula RbI. It is a white solid with a melting point of 642 °C.

<span class="mw-page-title-main">Germanium(II) iodide</span> Chemical compound

Germanium(II) iodide is an iodide of germanium, with the chemical formula of GeI2.

Polyhalogen ions are a group of polyatomic cations and anions containing halogens only. The ions can be classified into two classes, isopolyhalogen ions which contain one type of halogen only, and heteropolyhalogen ions with more than one type of halogen.

<span class="mw-page-title-main">Germanium(IV) iodide</span> Chemical compound

Germanium(IV) iodide is an inorganic compound with the chemical formula GeI4.

Iron(II) iodide is an inorganic compound with the chemical formula FeI2. It is used as a catalyst in organic reactions.

<span class="mw-page-title-main">Molybdenum(III) iodide</span> Chemical compound

Molybdenum(III) iodide is the inorganic compound with the formula MoI3.

<span class="mw-page-title-main">Indium(III) iodide</span> Chemical compound

Indium(III) iodide or indium triiodide is a chemical compound of indium and iodine with the formula InI3.

Iron(III) iodide is an inorganic compound with the chemical formula FeI3. It is a thermodynamically unstable compound that is difficult to prepare. Nevertheless, iron(III) iodide has been synthesised in small quantities in the absence of air and water.

Polonium tetraiodide is a binary inorganic compound of polonium and iodine with the chemical formula PoI
4. The compound forms volatile black crystals.

<span class="mw-page-title-main">Praseodymium(III) iodide</span> Chemical compound

Praseodymium(III) iodide is an inorganic salt, consisting of the rare-earth metal praseodymium and iodine, with the chemical formula PrI3. It forms green crystals. It is soluble in water.

Europium(III) iodide is an inorganic compound containing europium and iodine with the chemical formula EuI3.

<span class="mw-page-title-main">Disulfur diiodide</span> Chemical compound

Disulfur diiodide is an unstable inorganic chemical compound with the chemical formula S2I2. Its empirical formula is SI. It is a red-brown solid that decomposes above −30 °C to elemental sulfur and iodine.

<span class="mw-page-title-main">Rhenium(III) iodide</span> Chemical compound

Rhenium(III) iodide is a binary chemical compound of rhenium and iodide with the chemical formula ReI
3.

Rhenium tetraiodide is a binary chemical compound of rhenium and iodide with the chemical formula ReI
4.

<span class="mw-page-title-main">Tantalum(IV) iodide</span> Chemical compound

Tantalum(IV) iodide is an inorganic compound with the chemical formula TaI4. It dissolves in water to give a green solution, but the color fades when left in the air and produces a white precipitate.

References

  1. ↑ "Tellurium tetraiodide". pubchem.ncbi.nlm.nih.gov. Retrieved 13 December 2021.
  2. 1 2 3 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN   978-0-08-037941-8.
  3. 1 2 Inorganic Chemistry,Egon Wiberg, Arnold Frederick Holleman Elsevier 2001 ISBN   0-12-352651-5
  4. 1 2 Handbuch der präparativen anorganischen Chemie. 1 (3., umgearb. Aufl ed.). Stuttgart: Enke. 1975. p. 435. ISBN   978-3-432-02328-1.
  5. ↑ Hagen, A. P. (2009-09-17). Inorganic Reactions and Methods, The Formation of Bonds to Halogens (Part 1). John Wiley & Sons. ISBN   978-0-470-14538-8.
  6. ↑ Tellurium(IV) iodide, 99% (metals basis) at AlfaAesar, accessed on 2013-12-17 ( PDF ) (JavaScript required).
  7. ↑ Riedel, Erwin; Janiak, Christoph (2011). Anorganische Chemie: Zusatzmaterial online. Studium (8. Aufl ed.). Berlin: de Gruyter. ISBN   978-3-11-022567-9.
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