Catalytic activity of iron and cobalt phthalocyanine complexes towards the oxidation of cyclohexene using tert-butylhydroperoxide and chloroperoxybenzoic acid
TL;DR: In this paper, cyclohexene oxidation using tert-butylhydroperoxide (TBHP) or chloroperoxybenzoic acid (CPBA) in the presence of iron(II) polychlorophthalocyanine (Cl16PcFe), iron (II) phthalocynine (PcCo) and cobalt(II), cobalt (III) phthoric acid (CoCo) catalysts, results in the formation of the following products.
Abstract: Cyclohexene oxidation using tert-butylhydroperoxide (TBHP) or chloroperoxybenzoic acid (CPBA) in the presence of iron(II) polychlorophthalocyanine (Cl16PcFe), iron(II) phthalocyanine (PcFe) and cobalt(II) phthalocyanine (PcCo), results in the formation of the following products: cyclohexene oxide, 2-cyclohexene-1-ol and 2-cyclohexene-1-one. Adipic acid was also formed after long reaction times. The selectivity for 2-cyclohexene-1-one is favoured when Cl16PcFe or PcCo catalysts are employed, while PcFe is selective towards the formation of 2-cyclohexene-1-ol. The Cl16PcFe catalyst is transformed into a μ-oxo dimer (Cl16PcFeIIIOIIIFePcCl16) during the oxidation process. The catalytic process using the unsubstituted PcCoII and PcFeII catalysts involved PcMIII species as an intermediate. The active form of the Cl16PcFe catalyst was stable to degradation in that it was still active even after 4 weeks of continued catalysis.
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752 citations
TL;DR: WhyPhthalocyanines are versatile building blocks for fabricating materials at the nanometer scale and are targets for different scientific purposes and technological applications is described.
715 citations
TL;DR: In this paper, the catalytic activity of different types of Schiff base was analyzed and presented in a review, showing that polymer-supported Schiff base complexes of metal ions show high catalytic performance in comparison to their unsupported analogues.
345 citations
TL;DR: In this paper, the performance of cobalt phthalocyanine and iron porphyrin network polymers of intrinsic microporosity (network-PIMs) was compared with that of low molar mass analogues.
Abstract: Cobalt phthalocyanine and iron porphyrin network polymers of intrinsic microporosity (network-PIMs) were prepared and their performance as heterogeneous catalysts compared with that of low molar mass analogues. Spiro-linked Co phthalocyanine network-PIMs prepared from preformed chlorinated phthalocyanines showed lower surface areas and lower catalytic activity than those prepared by a phthalocyanine-forming reaction from a rigid precursor incorporating a spiro-centre. However, all the phthalocyanine network-PIMs were much more effective catalysts than low molar mass Co phthalocyanine for the decomposition of hydrogen peroxide, the oxidation of cyclohexene and the oxidation of hydroquinone. An Fe porphyrin network-PIM showed a higher surface area than any of the phthalocyanine polymers and showed higher activity for the oxidation of hydroquinone, also outperforming a low molar mass FeCl porphyrin.
236 citations
TL;DR: In this article, a combinatorial approach was used to obtain a large variety of catalytic properties of μ-nitrido diiron phthalocyanine complexes, e.g., mild catalytic oxidation of methane in water at near-ambient conditions.
146 citations
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Book•
01 Jan 1989
TL;DR: In this paper, the most recent research on the fundamental and applied chemistry of the phthalocyanine derivatives is presented in a detailed and comprehensive way, including their redox character, essential to many of their potential industrial applications.
Abstract: This book brings together the most recent research on the fundamental and applied chemistry of the phthalocyanine derivatives. More particularly, their redox character, essential to many of their potential industrial applications, are presented in this book in a detailed and comprehensive way. Together, the three volumes cover a broad spectrum of the physical and chemical aspects of the phtalocyanines and some of their relatives, providing a firm, up-to-date basis for future exploration of these very important species. The unique properties of phthalocyanines have generated worldwide interest in their use in chemical sensors, electronic display devices, photoconduction, fuel cells, molecular metals, electrocatalysis, molecular computers, pollution control devices, liquid crystals, photodynamic therapy and biological stains.
2,338 citations
TL;DR: These and related reactivity studies suggest that catalysis of alkane oxygenation by Fe(TFPPBr8)Cl occurs through a radical-chain mechanism in which the radicals are generated by oxidation and reduction of alkyl hydroperoxides.
Abstract: Halogenation of an iron porphyrin causes severe saddling of the macrocyclic structure and a large positive shift in the iron(III)/(II) redox couple. Although pre-halogenated iron(II) porphyrins such as Fe(TFPPBr8) [H2TFPPBr8, beta-octabromo-tetrakis(pentafluorophenyl)-porphyrin] are relatively resistant to autoxidation, they rapidly reduce alkyl hydroperoxides. These and related reactivity studies suggest that catalysis of alkane oxygenation by Fe(TFPPBr8)Cl occurs through a radical-chain mechanism in which the radicals are generated by oxidation and reduction of alkyl hydroperoxides.
298 citations
TL;DR: In this paper, the authors measured the activity, regioselectivity, substrate selectivity, and stereoselectivities of the substituted iron porphyrin catalysts.
Abstract: The yields and product distributions in the oxidation of hydrocarbons (cyclohexane, n-pentane, n-octane, methylcyclohexane, tert-butylcyclohexane, and ethylbenzene), using substituted iron tetraphenylporphyrins and iodosobenzene, are shown to be markedly affected by nature and location of phenyl ring substituents. These substrates were used to measure the activity, regioselectivity, substrate selectivity, and stereoselectivity of the substituted iron porphyrin catalysts. Higher yields are observed with iron porphyrins having bulky substituents near the iron center. Kinetics measurements and concentration studies show that these substituents improve lifetimes by hindering the catalyst's bimolecular self-destruction. Higher yields are also observed with electron-withdrawing substituents. A new iron fluoro-pocket porphyrin shows higher activity due to this electronic effect. Substrate and regioselectivity are also influenced by steric and electronic effects of the iron porphyrin's phenyl ring substituents. Bulky porphyrins also affect the stereoselectivity at the 2-, 3-, and 4-positions in tert-butylcyclohexane oxidation. A mechanism supported by kinetic modeling studies is proposed for the oxidation reactions. 48 references, 14 figures, 5 tables.
188 citations
TL;DR: In this article, the perchlorinated manganese porphyrin ring stabilizes Mn(II) and unfavour the formation of the active species, Mn V O.
Abstract: Manganese(III) 5-(pentafluorophenyl)-10,15,20-tri(2,6-dichlorophenyl)porphyrin, Mn(PFTDCPP), and manganese(II) 2,3,7,8,12,13,17,18-octachloro-5-(pentafluorophenyl)-10,15-20-tri(2,6-dichlorophenyl)porphyrin, Mn(PFTDCCl 8 PP), have been synthesised and used as catalysts in hydrocarbon oxidations by iodosylbenzene and hydrogen peroxide both in solution and covalently bound to aminopropylated silica. The former shows higher efficiency in the epoxidation of alkenes by iodosylbenzene, whereas the perchlorinated manganese porphyrin is more efficient in the hydroxylation of alkanes by this oxidant. The supported manganese(III) porphyrin show the same activity as its homogeneous analogue. With hydrogen peroxide as oxygen donor, Mn(PFTDCPP) is a stable and effective catalyst in the presence of imidazole. The perchlorinated analogue is a poor catalyst with this oxidant. The eight additional chlorine atoms on the porphyrin ring stabilise Mn(II) and unfavour the formation of the active species, Mn V O.
126 citations
TL;DR: In this paper, the authors employed polychlorophthalocyanine (Cl 16 PcFe II ) and tetrasulfophthalocyanin (Fe II TSPc] 4− ) complexes of iron as catalysts for the oxidation of cyclohexane using tert -butyl hydroperoxide (TBHP), m -chloroperoxybenzoic acid (m -CPBA) and hydrogen peroxide as oxidants.
Abstract: Polychlorophthalocyanine (Cl 16 PcFe II ) and tetrasulfophthalocyanine ([Fe II TSPc] 4− ) complexes of iron are employed as catalysts for the oxidation of cyclohexane using tert -butyl hydroperoxide (TBHP), m -chloroperoxybenzoic acid ( m -CPBA) and hydrogen peroxide as oxidants. Catalysis using the Cl 16 PcFe II was performed in a dimethylformamide:dichloromethane (3:7) solvent mixture. For the [Fe II TSPc] 4− catalyst, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative yields of the products depended on oxidant and the catalyst. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. The mechanism of the oxidation of cyclohexane in the presence of the Cl 16 PcFe II and [Fe II TSPc] 4− involves the oxidation of these catalysts, forming an Fe(III) phthalocyanine species as an intermediate. Higher yields were observed when [FeTSPc] 4− was employed as a catalyst, which is more soluble than the perchlorinated iron phthalocyanine catalyst.
95 citations