Activation of H2O2 by methyltrioxorhenium(VII) inside beta-cyclodextrin

作者:Al Rawashdeh N A F*; Al Ajlouni A M; Bukallah S B; Bataineh N
来源:Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2011, 70(3-4): 471-480.
DOI:10.1007/s10847-010-9876-3

摘要

The effect of beta-cyclodextrin on the catalytic stability and reactivity of methylrhenium trioxide (MTO), CH3ReO3, which has been used for activation of hydrogen peroxide toward oxidation and epoxidation reactions, was studied using UV-Vis spectrophotometery. The stability and reactivity of the new catalytic system (MTO/beta-CD) to activate H2O2 toward oxidation of indigo blue dye were investigated in basic media. Furthermore, effects of inclusion stoichiometry, temperature and concentrations of hydrogen peroxide on the stability and reactivity of the MTO/beta-CD system were investigated. The formation of the inclusion complex between MTO and beta-CD was confirmed experimentally using the changes in the UV-Vis absorption spectra. The results of this study demonstrate that the complexation process was better guaranteed when the amount of beta-CD is higher than that of MTO, using a 1:2 molar ratio of MTO:beta-CD enhances both the activity and stability of the catalyst. The results showed that the stability of the catalytic system was enhanced in presence of beta-CD with maintaining good reactivity of the MTO even in the presence of high concentration of NaOH. The changes of thermodynamic activation parameters (Delta H-not equal and Delta S-not equal) for the oxidation reaction of indigo with H2O2 catalyzed by MTO/beta-CD system were determined on the basis of the experimental data.

  • 出版日期2011-8

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