tert ‐Butanol as an OH‐Scavenger in the Pulse Radiolysis of Oxygenated Aqueous Systems

The application of tert ‐butanol as an OH scavenger in aqueous, oxygenated solutions was studied by pulse radiolysis and computer simulation of the entire reaction mechanism. In such systems, the initially produced tert ‐butanol radical (· R tb ) reacts with O 2 with a rate constant of k = 1.4 · 10 9 M −1 s −1 . The UV absorption‐spectrum of the resulting tert ‐butanol peroxy‐radical, · OOR, tb , was determined. The rate constant for its dimerization, 2 · OOR tb R tb O 4 R tb , is k = 1.8 · 10 8 M −1 s −1 . The formation of HO 2 from the decay of R tb O 4 R tb has often been neglected in earlier studies. Our reinvestigation showed a yield of 5 ± 2%. In deoxygenated systems we confirmed the rate constant for · R tb dimerization to be k = 6 · 10 8 M −1 s −1 . The UV spectrum of · R tb was determined to be slightly different from literature data.