Tellurate


Tellurate
The structure of metatellurate and orthotellurate

The tellurate ion is TeO42− or TeO66−.

Unlike sulfate, tellurate is a somewhat good oxidizer; it can be reduced to tellurite or tellurium.

Tellurate exists in two forms, metatellurate ion, TeO42−, and orthotellurate ion, TeO66−.

Compounds include metatellurates and orthotellurates. Metatellurates are analogous to sulfates, but they are rare. Orthotellurates are much more common and this forms most of the chemistry of tellurates.

In neutral conditions, pentahydrogen orthotellurate ion, H5TeO6, is most common; in basic conditions, tetrahydrogen orthotellurate ion, H4TeO62−, is found; in acid conditions, the orthotelluric acid, H6TeO6 is formed.[1]

Contents

Properties

The metatellurate anion, TeO42−, has a molecular weight of 191.60 g/mole. It belongs to the Td molecular point group, thus it has a tetrahedral shape even though two of its oxygen atoms are double bonded.

TeO42− → TeO32− + 1/2O2 (E0= −1.042 V)

The E0 or standard reduction potential value is significant as it gives an indication of the strength of the tellurate ion as an oxidizing agent.[1]

The orthotellurate anion, TeO66−, has a molecular weight of 223.6 g/mole. It belongs to the Oh molecular point group, thus it has an octahedral shape.

NMR spectroscopy

Tellurium has two NMR active nuclei, 123Te and 125Te. 123Te has an abundance of 0.9% and a nuclear spin (I) of 1/2. 125Te has an abundance of 7% and an equivalent nuclear spin.[2] 125Te is more commonly performed because it has a higher sensitivity.[3] The metatellurate anion has a chemical shift around 610 ppm when analyzed using 125Te NMR at 25°C at a frequency of 94.735 MHz and referenced externally against aqueous 1.0 M telluric acid.[4]

List of some known salts involving metatellurate anions

Na2TeO4*2H2O

K2TeO4*2H2O

Rb2TeO4

Cs2TeO4

CaTeO4

Al2(TeO4)3

(NH4)2TeO4

References

  1. ^ a b Frost, R.L. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009, 72, 903.
  2. ^ Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. ISBN 978-0131755536. 
  3. ^ Drago, R. S. Physical Methods for Chemists 2nd ed.; Surfside Scientific Publishers: Gainesville, FL 1992.
  4. ^ Konaka, S.; Ozawa, Y.; Yagasaki, A. Inorg. Chem., 2008, 47, 1244.

External links


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Look at other dictionaries:

  • Tellurate — sind die Salze der Tellursäure (Orthotellursäure H6TeO6 und Metatellursäure H2TeO4) und enthalten das Orthotellurat(VI) Anion TeO66− beziehungsweise das Metatellurat(VI) Anion TeO42−. Auch die als Tellurite bezeichneten Salze der Tellurigen Säure …   Deutsch Wikipedia

  • tellurate — [ telyrat ] n. m. • 1832; de tellure ♦ Chim. Sel ou ester de l acide tellurique. ● tellurate nom masculin Sel d acide tellurique. tellurate [telyʀat] n. m. ÉTYM. 1836; de tellure …   Encyclopédie Universelle

  • Tellurate — Tel lu*rate, n. [Cf. F. tellurate. See {Tellurium}.] (Chem.) A salt of telluric acid. [1913 Webster] …   The Collaborative International Dictionary of English

  • tellurate — /tel yeuh rayt /, n. Chem. a salt of a telluric acid, as of H2TeO or H6TeO6. [1820 30; TELLUR(IC ACID) + ATE2] * * * …   Universalium

  • tellurate — noun any salt of telluric acid …   Wiktionary

  • tellurate — (tèl lu ra t ) s. m. Terme de chimie. Sel produit par la combinaison de l acide tellurique avec une base …   Dictionnaire de la Langue Française d'Émile Littré

  • tellurate — n. salt of telluric acid (Chemistry) …   English contemporary dictionary

  • tellurate — [ tɛljʊreɪt] noun Chemistry a salt or ester of telluric acid …   English new terms dictionary

  • tellurate — tel·lu·rate …   English syllables

  • tellurate — /ˈtɛljəreɪt/ (say telyuhrayt) noun a salt of telluric acid. {tellur(ic)2 + ate2} …   Australian English dictionary


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