2670
H.
The Journal of Physical Chetnistty, Vol. 82, No. 25, 1978
Zemel and R. W. Fessenden
The Mechanism of Reaction of SO4- with Some Derivatives of Benzoic Acid' H. Zeme12 and Richard W. F e ~ s e n d e n " ~ Departments of Chemistry and Radiation Laboratories, Carnegie-Meiion University, Pittsburgh, Pennsylvania 152 13, and The University of Notre Dame, Notre Dame, Indiana 46556 (Received May 2, 1978) Publication costs assisted by the Department of Energy
The products of the reactions of SO4- with some benzoic acid derivatives have been examined by ESR using steady-state radiolysis and photolysis to produce SO4-and by optical absorption spectrophotometry in pulse radiolysis experiments. The optical absorption spectrum of the hydroxycyclohexadienyl radical following reaction of benzene with SO4-is shown to be formed with 0.1 F S would delay the rise enough to significantly decrease the agreement. On this basis the lifetime of the intermediate before hydroxycyclohexadienyl radical must be