Fig. 5.

Plot of k_obs versus [CH₃CN] (circles, solid line) or [CD₃CN] (squares, dashed line) for reaction with H_peroxo at 4 °C and pH 7.0. 200 μM MMOH_red and 400 μM MMOB were mixed rapidly with excess O₂, the reaction mixture was aged for 2 s, and then buffer containing the appropriate concentration of acetonitrile was introduced. Data were analyzed as noted in the text. Error bars represent one standard deviation at the 95% confidence level.