Use of a fluoride ion selective electrode as a tool for monitoring relatively fast kinetic processes. Applications to the hydrolysis of organofluorophosphorus esters and 2,4-dinitrofluorobenzene

Experimental conditions have been designed which allowed the use of a fluor ide ion selective electrode for the monitoring of reactions that proceed wi th a moderately fast departure of F- ion, i.e., t(1/2) approximate to 30 se conds, in aqueous solution. The procedure applied in particular to the S(N) A(R) substitution of 1-fluoro-2,4-dinitrobenzene with p-chlorophenoxide ion and to the hydrolysis, catalyzed by oximate ions, of three organofluoropho sphorus esters, namely sarin, soman and diisopropylphosphorofluoridate (DFP ). Depending upon the system at hand, the required buffering of the solutio ns can be made up from the nucleophile reagent itself or through the use of an external buffer.