The phthalimide N-oxyl (PINO) radical was generated by the oxidation of N-hydroxyphthalimide (NHPI) with Pb(OAc) 4 in acetic acid. The molar absorptivity of PINO • is 1.36 × 10 3 L mol - 1 cm - 1 at λ max 382 nm. The PINO radical decomposes slowly with a second-order rate constant of 0.6 ± 0.1 L mol - 1 s - 1 at 25 °C. The reactions of PINO • with substituted toluenes, benzaldehydes, and benzyl alcohols were investigated under an argon atmosphere. The second-order rate constants were correlated by means of a Hammett analysis.
The catalyst provides a new pathway in the reaction mechanism. The catalyst speeds up the reaction. Two of the above. None of the above. Note that for a free-response question you must show the work (ratio of rate laws), but not for multiple choice. KINETICS Practice Problems and Solutions ] [] [ ]]. Reaction Modelling for Kinetic Processes. Reaction mechanisms. The program comes in both a free version, ReactLab™ KINSIM, and a licensed version.
The reactions with toluenes and benzyl alcohols have better correlations with σ + (ρ = −1.3 and −0.41), and the reaction with benzaldehydes correlates better with σ (ρ = −0.91). The kinetic isotope effect was also studied and significantly large values of k H/ k D were obtained: 25.0 ( p-xylene), 27.1 (toluene), 27.5 (benzaldehyde), and 16.9 (benzyl alcohol) at 25 °C. Vcds 12120 rus dlya kitajskogo shnurka. From the Arrhenius plot for the reactions with p-xylene and p-xylene- d 10, the difference of the activation energies, E a D − E a H, was 12.6 ± 0.8 kJ mol - 1 and the ratio of preexponential factors, A H/ A D, was 0.17 ± 0.05. 
These findings indicate that quantum mechanical tunneling plays an important role in these reactions.