Tellurol
Tellurols are analogues of
Properties
Alkyltellurols are colorless liquids with strong odors. Samples usually appear yellowish owing to the presence of dialkylditelluride impurities. Near room temperature, methanetellurol degrades with loss of elemental tellurium. It is reported to ignite in air.[3]
Aryltellurols are more robust and have been obtained as colorless crystals. Some of the most stable tellurols are the bulky silylated derivatives of tris(trimethylsilyl)methane and analogues. One series of readily isolable tellurols is (Me3Si)3CTeH, (Me3Si)3SiTeH, and (Me3Si)3GeTeH.[1]
Acid–base properties
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. H2Te has a lower pKa and higher dissociation constant than H2S and H2Se.[4] The pKa is 9.3 for (Me3Si)3CTeH vs 10.8 for (Me3Si)3CSeH.[1]
The absence of hydrogen-bonding explains the low boiling temperature of tellurols.[4]
Preparation
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).
References
- ^ S2CID 250864006.
- PMID 18257551.
- .
- ^ ISBN 9780471904250.