Hydroxy- and chloro-dediazoniation of 2- and 3-methylbenzenediazonium tetrafluoroborate in aqueous solution

We have measured the rates and product yields of dediazoniation of 2- and 3 -methylbenzenediazonium tetrafluoroborate in the presence and absence of el ectrolytes like HCl, NaCl, and CuCl2 using a recently reported methodology that allows simultaneous determination of product concentrations and rates of product formation and, indirectly, loss of starting material. Activation parameters were also obtained: enthalpies of activation are high, and entr opies of activation are positive. All results are consistent with a heterol ytic mechanism involving the fragmentation of the arenediazonium ion into a very reactive phenyl cation. (C) 1999 John Wiley & Sons, Inc.