Generation and Reactions of Thiyl Radicals

Generation and Reactions of Thiyl Radicals.—Pulse radiolysis studies of thiols in aqueous solutions at different pH s provide information on the competition between and RSH for the hydrated electron el, which reacts with RSH to give R +SH the hydroxyl radical produced concurrently by H2O cleavage produces thiyl radicals. 

Quantitative study of H abstraction by thiyl radicals is feasible using RS H as solvent.An unusual displacement reaction has been demonstrated for 2,2-diphenyl-1-picrylhydrazyl (15), which, on reaction with 2,4,6-tri-t-butylbenzenethiol, produces the arylthiyl radical by H abstraction, which then displaces NOi from a second hydrazyl.  

The dithiothreitol radical can exist in an ionized form (16) or as neutral species (17).  

Reactions of Thiols with Organophosphonis Compounds.—Autoxidation of thiols can be prevented by addition of tri-n-butylphosphine when the thiol solution is to be used, the phosphine is removed by extraction with a dilute solution of sulphur in CHCla.  

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