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Dediazoniation of Arenediazonium Ions in Homogeneous Solutions. Part XVII. Kinetics and mechanisms of dediazoniation of p-chlorobenzenediazonium tetrafluoroborate in weakly alkaline aqueous solutions in the presence of oxygen
The kinetics of dediazoniation of p‐chlorobenzenediazonium tetrafluoroborate have been studied in buffer solutions in the pH‐range 9.0–10.0, ionic strength I = 0.10, at 20.0° in glass and polytetrafluoroethylene vessels. The presence of oxygen (<5 ppb of O2, 60 to 100 ppb of O2, air, > 99% of O2) has a decisive influence on the rate and kinetic order of the dediazoniation. Iodoacetic acid inhibits the reaction, whereas p‐chlorophenol has a catalytic effect, and in air and >99% of O2 it acts as an autocatalyst. The reaction is subject to general‐base catalysis by water, hydroxyl ions, hydrogen carbonate and carbonate ions. The kinetic results are interpreted in conjunction with data concerning the reaction products [2] and a 15N‐CIDNP. investigation of a related system [3]. Specific radical chain mechanisms are consistent with the results.