ISSN:
0947-6539
Keywords:
chlorophenols
;
iron complexes
;
manganese complexes
;
phthalocyanines
;
polhutant degradation
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
2,4,6-trichlorophenol (TCP) is oxidized by potassium monopersulfate or hydrogen peroxide in the presence of iron or manganese tetrasulfonatophthalocyanines (FePcS or MnPcS) to yield not only the corresponding 2,6-dichloro-1,4-benzoquinone but also ring-cleavage products. Catalytic oxidation of the TCP ring by hydrogen peroxide is more efficient than by potassium monopersulfate, despite a slower substrate conversion, suggesting that different mechanisms are involved for these two catalytic systems: a metal-oxo mechanism for FePcS/KHSO5 and a metal-peroxo mechanism for FePcS/H2O2. Eight different final oxidation products and four quinone intermediates have been identified in the oxidation of TCP by the FePcS/H2O2 catalytic system. Chloromaleic acid is the main product of the oxidative ring cleavage. An iron-peroxo complex PcS-FeOOH is probably the active species responsible for the epoxidation of 2,6-dichloro-1,4-benzoquinone and the C-C bond cleavage of 3,5-dichloro-2-hydroxy-1,4-benzoquinone ring, both intermediates generated during the catalytic TCP degradation. The oxidation of pentachlorophenol (PCP) is also catalyzed by FePcS or MnPcS with KHSO5 or H2O2.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19960021019
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