Oxidation of Polycyclic Aromatic Hydrocarbons Catalyzed by Iron Tetrasulfophthalocyanine FePcS: Inverse Isotope Effects and Oxygen Labeling Studies
✍ Scribed by Alexander Sorokin; Bernard Meunier
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 659 KB
- Volume
- 1998
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
Iron(III) tetrasulfophthalocyanine (FePcS) was shown to sp 2 carbon center of anthracene to form a σ adduct (this inverse KIE being enhanced by stronger stacking catalyze the oxidation of polycyclic aromatic hydrocarbons by H 2 O 2 . Benzo[a]pyrene and anthracene were converted to interactions between the perdeuterated substrate with the macrocyclic catalyst). Although the first oxidation step seems the corresponding quinones while biphenyl-2,2Ј-dicarboxylic acid was the main product of phenanthrene oxidation. The to be the same, different distribution of the oxidation products of anthracene and very different 18 O incorporation mechanism of the anthracene oxidation by H 2 O 2 in the presence of FePcS or by KHSO 5 with iron(III) meso-into anthrone and anthraquinone in catalytic oxidations performed in the presence of H 2
18
O suggested that different tetrakis(3,5-disulfonatomesityl)porphyrin (FeTMPS) (see Figure 1 for catalyst structures) has been investigated in active species should be responsible for anthracene oxidation in both catalytic systems. All the results obtained are details by using kinetic isotope effects (KIEs) and 18 O labeling studies. KIEs measured on the substrate compatible with an involvement of TMPSFe V =O (or TMPS + Fe IV =O), having two redox equivalents above the consumption in the competitive oxidation of [H 10 ]anthracene and [D 10 ]anthracene by FePcS/H 2 O 2 and FeTMPS/KHSO 5 iron(III) state of the metalloporphyrin precursor, while PcSFe IV =O (one redox equivalent above Fe III state of FePcS) were essentially the same, 0.75 ± 0.02 and 0.76 ± 0.06, respectively. These inverse KIEs on the first oxidation step was proposed to be the active species in the metallophthalocyanine-based system. can be explained by the sp 2 -to-sp 3 hybridization change during the addition of an electrophilic oxoiron complex to the