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dc.contributor.authorIamamoto, Y.-
dc.contributor.authorCiuffi, K. J.-
dc.contributor.authorSacco, H. C.-
dc.contributor.authorIwamoto, L. S.-
dc.contributor.authorNascimento, O. R.-
dc.contributor.authorPrado, CMC-
dc.identifier.citationJournal of Molecular Catalysis A-chemical. Amsterdam: Elsevier B.V., v. 116, n. 3, p. 405-420, 1997.-
dc.description.abstractIn this work we have made use of the study of the interaction between Fe(TDCPP)(+) and the axial ligands OH- and imidazole in order to help characterize the heterogenized catalysts Fe(TDCPP)SG and Fe(TDCPP)IPG through UV-VIS and EPR spectroscopies and thus, better understand their different catalytic activity in the oxidation of cyclohexane by PhIO. We have found out that in Fe(TDCPP)SG (containing 1.2 X 10(-6) mol Fe(TDCPP)(+)/g of support), the FeP bis-coordinates to silica gel through Fe-O coordination and it is high-spin (FeP)-P-III species. In Fe(TDCPP)IPG 1 (containing 1.1 X 10(-6) mol Fe(TDCPP)(+) and 2.2 X 10(-4) mol imidazole/g of support), the FeP is bis-ligated to imidazole propyl gel through Fe-imidazole coordination and using NO as a paramagnetic probe, we present evidence that Fe(TDCPP)(+) is present as a mixture of low-spin (FeP)-P-III and (FeP)-P-II species. This catalyst led to a relative low yield of cyclohexanol (25%) because the bis-coordination of the (FeP)-P-III to the support partially blocks the reaction between Fe(TDCPP)(+) and PhIO, thus leading to the formation of only a small amount of the active species Fe-IV(OP+, while the (FeP)-P-II species do not react with the oxygen donor. Increasing the amount of Fe(TDCPP)(+) and decreasing the amount of imidazole in the support led to the obtention of high-spin (FeP)-P-III EPR signals in the spectra of Fe(TDCPP)IPG 5 (containing 4.4 X 10(-6) mol Fe(TDCPP)(+) and 2.2 X 10(-5) mol imidazole/g of IPG), together with low-spin (FeP)-P-III species. This latter catalyst led to better cyclohexanol yields (67%) than Fe(TDCPP)IPG 1. Fe(TDCPP)IPG 5 was further used in a study of the optimization of its catalytic activity and in recycling experiments in the optimized conditions. Recycling oxidation reactions of Fe(TDCPP)IPG 5 led to a total turnover number of 201 and total cyclohexanol yield of 201%, which could not be attained with Fe(TDCPP)Cl in homogeneous solution (turnover = 96) due to the difficulty in recovering and reusing it.en
dc.publisherElsevier B.V.-
dc.sourceWeb of Science-
dc.subjectimidazole propyl gelpt
dc.subject2,6-dichlorophenyl porphyrinpt
dc.subjectsupported catalystspt
dc.titleCharacterization and catalytic activity of 2,6-dichlorophenyl substituted iron(III) porphyrin supported on silica gel and imidazole propyl gelen
dc.contributor.institutionUniversidade de São Paulo (USP)-
dc.contributor.institutionUniversidade Estadual Paulista (UNESP)-
dc.description.affiliationUNESP,INST QUIM,ARARAQUARA,SP,BRAZIL-
dc.description.affiliationUnespUNESP,INST QUIM,ARARAQUARA,SP,BRAZIL-
dc.rights.accessRightsAcesso restrito-
dc.relation.ispartofJournal of Molecular Catalysis A: Chemical-
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

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