The catalytic cycle of the polymerization of 2,6-xylenol catalyzed by the copper-pyridine complex is divided into four elementary processes, the coordination of the substrate (k1), the electrontransfer from the substrate to the cupric ion (k0), the dissociation of the activated substrate (kd) and the reoxidation of the catalyst (k0). The rate constant of each elementary reaction was determined by means of the stopped-flow spectrophotometric study of the copper complex, and the detailed mechanism of the catalysis was discussed. From the comparison of rate constants (Table 1), the process involning. either ke or kd was considered to be the rate-determining step but the latter could not be measured in the present procedure. It was found that the oxygen molecule was involved in the cupric substrate complex, promoting the ke process. The rate constants were affected by the components of the solvent. Except for a few cases where solvents having coordinating ability are used, k1 and k0 increased and k0 decreased with the increasing solvent polarity.
|Number of pages||4|
|Journal||Nippon Kagaku Kaishi / Chemical Society of Japan - Chemistry and Industrial Chemistry Journal|
|Publication status||Published - 1974|
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