Hydrogen telluride

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Hydrogen telluride
Hydrogen telluride.png
Liquid hydrogen telluride in a test tube
Hydrogen-telluride-2D-dimensions.svg
Hydrogen-telluride-3D-vdW.svg
  Tellurium, Te
  Hydrogen, H
Names
IUPAC name
hydrogen telluride
Other names
hydrotelluric acid
tellane
tellurium hydride
dihydrogen telluride
tellurane
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.029.073 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 236-813-4
PubChem CID
UNII
  • InChI=1S/H2Te/h1H2 X mark.svgN
    Key: VTLHPSMQDDEFRU-UHFFFAOYSA-N X mark.svgN
  • [TeH2]
Properties
H2Te
Molar mass 129.6158 g mol−1
Appearancecolourless gas
Odor Pungent, resembles rotting garlic or leeks
Density 3.310 g/L, gas
2.57 g/cm3 (−20 °C, liquid)
Melting point −49 °C (−56 °F; 224 K) [1]
Boiling point −2.2 °C (28.0 °F; 270.9 K) (unstable above −2 °C)
0.70 g/100 mL
Acidity (pKa)2.6
Conjugate acid Telluronium
Conjugate base Telluride
Structure
bent
Thermochemistry
0.7684 kJ/g
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
toxic
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
4
4
1
Related compounds
Other anions
H2O
H2S
H2Se
H2Po
Other cations
Na2Te
Ag2Te
K2Te
Rb2Te
Cs2Te
Related compounds
 telluric acid
tellurous acid
stibine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Hydrogen telluride is the inorganic compound with the formula H 2 Te. A hydrogen chalcogenide and the simplest hydride of tellurium, it is a colorless gas. Although unstable in ambient air, the gas can exist at very low concentrations long enough to be readily detected by the odour of rotting garlic at extremely low concentrations; or by the revolting odour of rotting leeks at somewhat higher concentrations. Most compounds with Te–H bonds (tellurols) are unstable with respect to loss of H2. H2Te is chemically and structurally similar to hydrogen selenide, both are acidic. The H–Te–H angle is about 90°. Volatile tellurium compounds often have unpleasant odours, reminiscent of decayed leeks or garlic. [2]

Contents

Synthesis

Electrolytic methods have been developed. [3]

H2Te can also be prepared by hydrolysis of the telluride derivatives of electropositive metals. [4] The typical hydrolysis is that of aluminium telluride:

Al2Te3 + 6 H2O → 2 Al(OH)3 + 3 H2Te

Other salts of Te2− such as MgTe and sodium telluride can also be used. Na2Te can be made by the reaction of Na and Te in anhydrous ammonia. [5] The intermediate in the hydrolysis, HTe−
, can be isolated as salts as well. NaHTe can be made by reducing tellurium with NaBH
4. [5]

Hydrogen telluride cannot be efficiently prepared from its constituent elements, in contrast to H2Se. [3]

Properties

H
2Te is an endothermic compound, degrading to the elements at room temperature:

H
2Te → H
2 + Te

Light accelerates the decomposition. It is unstable in air, being oxidized to water and elemental tellurium: [6]

2 H
2Te + O
2 → 2 H
2O + 2 Te

It is almost as acidic as phosphoric acid (Ka = 8.1×10−3), having a Ka value of about 2.3×10−3. [6] It reacts with many metals to form tellurides. [7]

See also

Related Research Articles

<span class="mw-page-title-main">Chalcogen</span> Group of chemical elements

The chalcogens are the chemical elements in group 16 of the periodic table. This group is also known as the oxygen family. Group 16 consists of the elements oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and the radioactive elements polonium (Po) and livermorium (Lv). Often, oxygen is treated separately from the other chalcogens, sometimes even excluded from the scope of the term "chalcogen" altogether, due to its very different chemical behavior from sulfur, selenium, tellurium, and polonium. The word "chalcogen" is derived from a combination of the Greek word khalkόs (χαλκός) principally meaning copper, and the Latinized Greek word genēs, meaning born or produced.

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

Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical. The corresponding electrically neutral compound HO• is the hydroxyl radical. The corresponding covalently bound group –OH of atoms is the hydroxy group. Both the hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry.

<span class="mw-page-title-main">Tellurium</span> Chemical element, symbol Te and atomic number 52

Tellurium is a chemical element; it has symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally found in its native form as elemental crystals. Tellurium is far more common in the Universe as a whole than on Earth. Its extreme rarity in the Earth's crust, comparable to that of platinum, is due partly to its formation of a volatile hydride that caused tellurium to be lost to space as a gas during the hot nebular formation of Earth.

The telluride ion is the anion Te2− and its derivatives. It is analogous to the other chalcogenide anions, the lighter O2−, S2−, and Se2−, and the heavier Po2−.

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

Tellurium dioxide (TeO2) is a solid oxide of tellurium. It is encountered in two different forms, the yellow orthorhombic mineral tellurite, β-TeO2, and the synthetic, colourless tetragonal (paratellurite), α-TeO2. Most of the information regarding reaction chemistry has been obtained in studies involving paratellurite, α-TeO2.

<span class="mw-page-title-main">Tellurate</span> Compound containing an oxyanion of tellurium

In chemistry tellurate is a compound containing an oxyanion of tellurium where tellurium has an oxidation number of +6. In the naming of inorganic compounds it is a suffix that indicates a polyatomic anion with a central tellurium atom.

<span class="mw-page-title-main">Telluric acid</span> Chemical compound (Te(OH)6)

Telluric acid, or more accurately orthotelluric acid, is a chemical compound with the formula Te(OH)6, often written as H6TeO6. It is a white crystalline solid made up of octahedral Te(OH)6 molecules which persist in aqueous solution. In the solid state, there are two forms, rhombohedral and monoclinic, and both contain octahedral Te(OH)6 molecules, containing one hexavalent tellurium (Te) atom in the +6 oxidation state, attached to six hydroxyl (–OH) groups, thus, it can be called tellurium(VI) hydroxide. Telluric acid is a weak acid which is dibasic, forming tellurate salts with strong bases and hydrogen tellurate salts with weaker bases or upon hydrolysis of tellurates in water. It is used as tellurium-source in the synthesis of oxidation catalysts.

<span class="mw-page-title-main">Selenium dioxide</span> Chemical compound

Selenium dioxide is the chemical compound with the formula SeO2. This colorless solid is one of the most frequently encountered compounds of selenium.

<span class="mw-page-title-main">Tellurous acid</span> Chemical compound

Tellurous acid is an inorganic compound with the formula H2TeO3. It is the oxoacid of tellurium(IV). This compound is not well characterized. An alternative way of writing its formula is (HO)2TeO. In principle, tellurous acid would form by treatment of tellurium dioxide with water, that is by hydrolysis. The related conjugate base is well known in the form of several salts such as potassium hydrogen tellurite, KHTeO3.

<span class="mw-page-title-main">Sodium tellurite</span> Chemical compound

Sodium tellurite is an inorganic tellurium compound with formula Na2TeO3. It is a water-soluble white solid and a weak reducing agent. Sodium tellurite is an intermediate in the extraction of the element, tellurium; it is a product obtained from anode slimes and is a precursor to tellurium.

<span class="mw-page-title-main">Sodium telluride</span> Chemical compound

Sodium telluride is the chemical compound with the formula Na2Te. This salt is the conjugate base of the thermally unstable acid hydrogen telluride, but it is usually prepared by reduction of tellurium with sodium. Na2Te is a challenging material to handle because it is very sensitive to air. Air oxidizes it initially to polytellurides, which have the formula Na2Tex (x > 1), and ultimately Te metal. Samples of Na2Te, which are colourless when absolutely pure, generally appear purple or dark gray due to the effects of air oxidation.

<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:

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

Tellurium tetraiodide (TeI4) is an inorganic chemical compound. It has a tetrameric structure which is different from the tetrameric solid forms of TeCl4 and TeBr4. In TeI4 the Te atoms are octahedrally coordinated and edges of the octahedra are shared.

Organotellurium chemistry describes the synthesis and properties of organotellurium compounds, chemical compounds containing a carbon-tellurium chemical bond. Organotellurium chemistry is a lightly studied area, in part because of it having few applications.

Selenium hexafluoride is the inorganic compound with the formula SeF6. It is a very toxic colourless gas described as having a "repulsive" odor. It is not widely encountered and has no commercial applications.

<span class="mw-page-title-main">Polonium hydride</span> Chemical compound

Polonium hydride (also known as polonium dihydride, hydrogen polonide, or polane) is a chemical compound with the formula PoH2. It is a liquid at room temperature, the second hydrogen chalcogenide with this property after water. It is very unstable chemically and tends to decompose into elemental polonium and hydrogen. It is a volatile and very labile compound, from which many polonides can be derived. Additionally, it is radioactive.

<span class="mw-page-title-main">Tellurol</span>

Tellurols are analogues of alcohols and phenols where tellurium replaces oxygen. Tellurols, selenols, and thiols have similar properties, but tellurols are the least stable. Although they are fundamental representatives of organotellurium compounds, tellurols are lightly studied because of their instability. Tellurol derivatives include telluroesters and tellurocyanates (RTeCN).

<span class="mw-page-title-main">Sulfur tetrachloride</span> Chemical compound

Sulfur tetrachloride is an inorganic compound with chemical formula SCl4. It has only been obtained as an unstable pale yellow solid. The corresponding SF4 is a stable, useful reagent.

Hydrogen chalcogenides are binary compounds of hydrogen with chalcogen atoms. Water, the first chemical compound in this series, contains one oxygen atom and two hydrogen atoms, and is the most common compound on the Earth's surface.

Tellurium compounds are compounds containing the element tellurium (Te). Tellurium belongs to the chalcogen family of elements on the periodic table, which also includes oxygen, sulfur, selenium and polonium: Tellurium and selenium compounds are similar. Tellurium exhibits the oxidation states −2, +2, +4 and +6, with +4 being most common.

References

  1. ↑ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN   0-8493-0487-3.
  2. ↑ Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. ISBN   0-7506-3365-4.
  3. 1 2 F. Fehér, "Hydrogen Telluride" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. pp. 438.
  4. ↑ Shriver, Atkins. Inorganic Chemistry, Fifth Edition. W. H. Freeman and Company, New York, 2010; pp 407.
  5. 1 2 Nicola Petragnani; Hélio A. Stefani (2007). Tellurium in organic synthesis. Best synthetic methods (2nd ed.). Academic Press. p. 6. ISBN   978-0-08-045310-1.
  6. 1 2 Egon Wiberg; Arnold Frederick Holleman (2001). Nils Wiberg (ed.). Inorganic chemistry. Translated by Mary Eagleson. Academic Press. p. 589. ISBN   0-12-352651-5.
  7. ↑ Henry Enfield Roscoe; Carl Schorlemmer (1878). A treatise on chemistry. Vol. 1. Appleton. pp. 367–368.
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