Thiolate ions reaction with diazonium

Aryl thiolates react with aryl diazonium ions to give diaryl sulfides. This reaction is believed to be a radical-chain process, similar to the mechanism for reaction of diazonium... 

The kinetics of the reaction of diazonium ions XCgH4Nj with benzene-thiolate anions show that initially the syn- azo thioether is formed rapidly, which is followed by the slower syn-anti isomerism. Only in the cases of p-nitro- and p-cyano-benzenediazonium ions is it possible to distinguish between the first and second reactions. Using benzenediazonium ion and the p-Me- and p-OCHj-substituted ions with benzenethiolate, first-order kinetics were observed over the entire range of the reaction. It is postulated that there the rate-determining step is formation of the spn-diazothioether, followed by its rapid isomerization to the ant/ -diazothioether . 

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