Dehydrosulphidation

Dehydrosulphidation of thiols and sulphides is directly analogous to dehydration of alcohols and ethers. Thiols (mercaptans) yield both alkenes and sulphides... 

The same catalysts as for dehydration are suitable for the dehydrosulphidation, i.e. alumina, silica—alumina, zeolites, metal oxides and metal sulphides. (For a comparison of their activities, see ref. 247.)... 

No detailed kinetic study of thiol or sulphide dehydrosulphidation has been reported, but first-order kinetics have been assumed for measurements with a pulse flow reactor and found acceptable [248,249]. 

By analogy with other elimination reactions and on the basis of observed structure effects on the rate, the El and E2-like mechanisms may also be accepted for the dehydrosulphidation. Sugioka and Aomura [248, 249,253] have proposed mechanisms which correspond to the above designations. Their results on ethanethiol decomposition over a series of... 

Fig. 9. Taft correlation of the dehydrosulphidation of alkanethiols (line 1, p = —33) and of dialkylsulphides (line 2, p = —38). (Data by Sugioka and Aomura [248].)...

Fig. 10. Dependence of the dehydrosulphidation rate of ethanethiol over zeolite catalysts with different cations on the electronegativity of the cation X (after ref. 249).

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