Efficient oxidations and photooxidations with molecular oxygen using metal phthalocyanines as catalysts and photocatalysts

Abstract

Metal phthalocyanines can be very efficient as catalysts and photocatalysts in oxidation reactions using molecular oxygen as oxidant. Different types of soluble low molecular weight or oligomeric and insoluble heterogeneous catalysts and photocatalysts were developed. The heterogeneous metal phthalocyanines exist either impregnated on SiO 2, Al 2 O 3, charcoal and TiO 2 or covalently and coordinatively bound on SiO 2 and organic polymers or ionically bound on an organic ion exchanger. The catalytic oxidations of toxic sulfide and thiol derivative are studied. In addition, toxic phenols were employed as substrates for the photooxidation. Heterogeneous catalysts can exhibit higher activities then low molecular weight phthalocyanines. These systems exhibit a good stability for re-use. Photooxidations are more efficient than oxidations. A Si(IV) phthalocyanine derivative on a polymer ion exchanger is most active and stable. Also some examples for photooxidations in the direction of photochemical synthesis are given.

Some Phthalocyanine and Naphthalocyanine Derivatives as Corrosion Inhibitors for Aluminium in Acidic Medium: Experimental, Quantum Chemical Calculations, QSAR Studies and Synergistic Effect of Iodide Ions

“…Their distinct physicochemical properties and the unique redox chemistry of their metal complexes have brought about their incorporation into a large number of donor-acceptor systems in which they function efficiently as light-harvesting substances and electron donors to an acceptor unit [17]. Their metal complexes have also been reportedly used for various photocatalytic and electrocatalytic applications [18][19][20].…”

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Abstract:The effects of seven macrocyclic compounds comprising four phthalocyanines (Pcs) namely 1,4,8,11,15,18,22,2,3,9,10,16,17,23,2,9,16, and 29H,31H-phthalocyanine (Pc4), and three naphthalocyanines namely 5,9,14,18,23,27,32,2,11,20, properties of the compounds were also investigated. All the studied compounds showed appreciable inhibition efficiencies, which decrease with increasing temperature from 30 °C to 70 °C.

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Ionic Interactions between Charged Phthalocyanine and Fullerene Derivatives

“…[25,26] Phthalocyanines were investigated in detail for the photocatalytic oxidations of sulfur compounds, phenols and in organic synthesis. [8,16,25,26] Further, phthalocyanines are active photosensitizers in the photodynamic therapy of cancer. [27] In the case of phthalocyanines as sensitizers thiols are oxidized under irradiation to sulfonic acids (Equation 2).…”

“…[27] In the case of phthalocyanines as sensitizers thiols are oxidized under irradiation to sulfonic acids (Equation 2). [16,25] [28,29] Singlet oxygen subsequently oxidizes the thiol to the corrsponding sulfonic acid (Equation 5). It will be shown that the addition of fullerene derivatives can positively influence the photocatalytic activity of phthalocyanines in the photooxidation.…”

“…The reaction conditions were described previously. [16,25] The photooxidation curves with the oxygen consumption over time are shown in the Figures 7 and 8.…”