Tellurol

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Tellurols are analogues of alcohols and phenols where tellurium replaces oxygen.[1] Tellurols, selenols, and thiols have similar properties, but tellurols are the least stable.[2] Although they are fundamental representatives of organotellurium compounds, tellurols are lightly studied because of their instability. Tellurol derivatives include telluroesters (RC(O)TeR') and tellurocyanates (RTeCN).

Properties[edit]

Alkyltellurols are yellow liquids with a strong odors. Aryltellurols form colorless crystals. More stable than these compounds are the organoelement tellurols. These fairly stable compounds have the formulae (Me3Si)3CTeH, (Me3Si)3SiTeH, and (Me3Si)3GeTeH.

Acid–base properties[edit]

The acidity of tellurols can be inferred by the acidity and dissociation constant of hydrogen telluride, H2Te, which has a (first) pKa of 2.64 corresponding to a dissociation constant of 2.3 × 10-3.5. H2Te has a lower pKa and higher dissociation constant than H2S and H2Se.[3]

The absence of hydrogen-bonding explains the low boiling temperature of tellurols.[3] The Te–H bond in tellurols is weak. Tellurols are easily oxidized and decompose thermally. Ultraviolet light also induces decomposition. Methanetellurol decomposes to dimethyl ditelluride and hydrogen.

Preparation[edit]

The first tellurol to be synthesized, ethanetellurol, was prepared in 1926 via the Grignard reagent.[1] The most frequently used method involves reduction of the ditellurides (R2Te2).

See also[edit]

References[edit]

  1. ^ a b Igor D Sadekov and A V Zakharov 1999 "Stable tellurols and their metal derivatives" Russ. Chem. Rev. 1999, vol. 68, 909.
  2. ^ Brahim Khater, Jean-Claude Guillemin, Gábor Bajor, Tamás Veszprémi "Functionalized Tellurols: Synthesis, Spectroscopic Characterization by Photoelectron Spectroscopy, and Quantum Chemical Study" Inorganic Chemistry 2008 volume 47, p. 1502-1511. doi:10.1021/ic701791h
  3. ^ a b Patai, Saul, and Zvi Rappoport. The Chemistry of Organic Selenium and Tellurium Compounds. Vol. 1. Chichester England: Wiley, 1986.