- Selective oxidation of 2-naphthol to 2-hydroxy-1,4-naphthoquinone with hydrogen peroxide catalyzed by 5,10,15,20-tetrakis(p-sulfonatophenyl)porphinatomanganese(III) chloride in aqueous solution.
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2-Naphthol has been selectively oxidized to 2-hydroxy-1,4-naphthoquinone (HNQ, Lawsone) with hydrogen peroxide in presence of 5,10,15,20-tetrakis-(p-sulfonatophenyl)porphinatomanganese (III) chloride as catalyst in alkaline aqueous solution. The catalytic oxidation afforded 2-hydroxy-1,4-naphthoquinone in high yield (95%). The effect of reaction parameters on the catalytic activity and the yield of HNQ have been investigated. UV–vis spectral analysis during oxidation reaction indicated that oxomanganese intermediate O = Mn(IV)TPPSCl was the active species in the oxidation reaction.
- Hassanein,El-Khalafy,Shendy
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- Highly efficient electrocatalytic hydrogen evolution from neutral aqueous solution by water soluble copper (II) porphyrin
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A water soluble Cu (II) porphyrin bearing para-sulfonic group at mesophenyl rings is reported as molecular electrocatalyst for H2 generation from neutral aqueous solution. Electrocatalysis study in buffer solution of pH 7.2 showed that the complex is highly active, efficient and stable toward H2 evolution. It features an observed rate constant (kobs) of 8.6 × 103 s?1 and Faradaic efficiency of 98.3% at an overpotential of 470 mV. The role of functional group on catalytic activity is also investigated by conducting heterogeneous catalysis involving Cu-porphyrin with (CuTPPS) and without (CuTPP) para-sulfonic groups. Hence differential pulse voltammetry, controlled-potential electrolysis and electrochemical impedance spectroscopic measurements show that, CuTPPS-modified electrode perform much better than that of CuTPP-modified. This may be attributed to an increase in the amount of catalyst at the vicinity of electrode surface because of the ability of para-sulfonic functional group to anchor to electrode surface. Moreover, its electron withdrawing behaviour and ability to donate proton to the solution in turn thermodynamically favour H2 evolution.
- Beyene, Belete B.,Yibeltal, Amogne W.,Hung
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- Metal chelates of porphyrin derivatives as sensitizers in photooxidation processes of sulfur compounds and in photodynamic therapy of cancer
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A number of porphyrin derivatives based on hematoporphyrin, 5,10,15,20-tetrasubstituted porphyrins, phthalocyanines, and naphthalocyanines were prepared either as low-molecular compounds or bonded with methoxypoly(ethylene glycol) or attached to silica of low surface area.The low-molecular weight and the polymer-bonded porphyrins exhibit comparable triplet lifetimes and activities in the photosensitized formation of singlet oxygen.For photon-induced processes, the monomeric state of sensitizers is fundamentally important.The porphyrins have been investigated as sensitizers for photooxidation of thiolates and sulfides, which occurs via singlet oxygen, and, therefore, is much more efficient that the corresponding catalytic dark oxidation.Polymer-bonded porphyrins and long-wavelength absorbing naphthalocyanines incorporated in liposomes exhibit in vivo high accumulation in tumor tissues.Under irradiation, singlet oxygen is produced, and efficient phototherapeutic effects are observed, which may be used for photodynamic cancer therapy. - Key words: metal chelates of porphyrin derivatives; photodynamic therapy of cancer.
- Woerle, D.,Wendt, A.,Weitemeyer, A.,Stark, J.,Spiller, W.,et al.
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- Porphyrin chemistry pertaining to the design of anti-cancer drugs; part 2. The synthesis and in vitro tests of water-soluble porphyrins containing, in the meso positions, the functional groups: 4-methylpyridinium, or 4-sulfonatophenyl, in combination with phenyl, 4-pyridyl, 4-nitrophenyl, or 4-aminophenyl
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Water-soluble, meso-substituted porphyrins are synthesized by sulfonation or methylation of the phenyl or pyridyl groups, respectively, of some non-water-soluble functionalized porphyrins that we have recently synthesized (Can. J. Chem. 72, 1894 (1994)). Twelve anionic sulfonated and seven cationic methylpyridinium porphyrins, usually containing other functional groups (phenyl, pyridyl, nitro- and amino-phenyl), are reported on. Twelve of these porphyrins are new, and all nineteen porphyrins are characterized by 1H NMR. UV-VIS data are presented for the isolated porphyrins, while mass spectral data are noted for selected compounds. Partition coefficients of the porphyrins in octanol-water, and the accumulation of the porphyrins in HT-29 cells of a human-cancer tumor, were measured and both were inversely related to the charges of the porphyrins. The 11 porphyrins soluble in biological buffer solutions are basically nontoxic to Chinese hamster ovary (CHO) cells in oxic or hypoxic conditions or to aerobic HT-29 cells at the 100 μM concentration used (which is sometimes limited by solubility). No significant X-ray radiosensitization was observed for selected porphyrins toward CHO cells at the 100 μM concentrations used, but some photosensitized cell kill (using 630 nm light) was observed using the disodium salt of 5, 10-bis(4-pyridyl)-15,20-bis(4-sulfonatophenyl)porphyrin (24).
- Meng,James,Skov,Korbelik
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- Solvent effects on catalytic activity of manganese porphyrins with cationic, anionic and uncharged meso substituents: Indirect evidence on the nature of active oxidant species
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Oxidation of cyclohexene and styrene with sodium periodate and tetra-n-butylammonium periodate (TBAP) catalyzed by MnT(3-MePy)P(OAc), MnT(4-SO3)PP(OAc) and MnTPP(OAc) has been studied in water, methanol, acetonitrile and dichloromethane as solvents. The results show significant dependence of the product distribution on the type of solvent and the electronic nature of the aryl substituents introduced at the porphyrin periphery. While the oxidation of cyclohexene and styrene in the presence of MnT(3-MePy)P(OAc) and MnTPP(OAc) in water (also in methanol) gave the corresponding epoxides as nearly the sole product, performing the reactions in the presence of MnT(4-SO3)PP(OAc) yielded the products of allylic oxidation, cyclohexene-2-ol and cyclohexene-2-one and acetophenone as the major products. In the case of styrene, performing the reaction in the presence of MnT(4-SO3)PP(OAc), MnT(3-MePy)P(OAc) and MnTPP(OAc) in acetonitrile gave a mixture of styrene oxide and acetophenone as the products. Under the same conditions, the oxidation of cyclohexene afforded cyclohexene oxide as approximately the exclusive product. Furthermore, the oxidation of olefins in dichloromethane gave the corresponding epoxide as the exclusive products. The product distributions observed in the protic and aprotic solvents were used to provide indirect evidence on the relative contribution and reactivity of high valent manganese oxo and periodato Mn(III) porphyrin species to the oxidation reactions.
- Esfandiari bayat, Zahra,Rahiminezhad, Hajar,Zakavi, Saeed
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- Spontaneous mirror-symmetry breaking coupled to top-bottom chirality transfer: From porphyrin self-assembly to scalemic Diels-Alder adducts
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This report shows how the net supramolecular chirality that emerged by spontaneous mirror-symmetry breaking (SMSB) at the mesoscale level can be transferred towards asymmetric solution chemistry. The J-aggregates obtained by self-assembly of an achiral porphyrin act as chiral counteranions in an iminium-promoted Diels-Alder reaction, leading to enantiomeric imbalances in the final adducts.
- Arlegui, Aitor,Soler, Bernat,Galindo, Alex,Arteaga, Oriol,Canillas, Adolf,Ribó, Josep M.,El-Hachemi, Zoubir,Crusats, Joaquim,Moyano, Albert
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supporting information
p. 12219 - 12222
(2019/10/22)
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- Electrochemical hydrogen evolution by cobalt (II) porphyrins: Effects of ligand modification on catalytic activity, efficiency and overpotential
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Electrochemical H2 evolution of a series of cobalt(II) porphyrins with electron-withdrawing (EW) and electron-donating (ED) substituents at the para positions of the meso-phenyl rings has been investigated in DMSO using acetic acid as a proton source. Our study showed that the nature of substituents significantly influences catalytic activity, efficiency, and the potential at which catalysis occurs. Faradaic efficiencies (FE) ranging from 44 to 99%, turnover numbers (TONs) from 1.5 to 104 (~11 h electrolysis), turnover frequencies (TOFs) from 0.23 to 9.1 h?1, and onset overpotentials from 25 to 445 mV were obtained by tuning the porphyrinic substituents. Cobalt porphyrins with -SO3H, -COOH, or -NH2 groups as the substituents showed high activity and efficiency with more positive onset potentials as compared to the parent [Co(TPP)]. Supports also from the low hydrogen generation activities for complexes with -COOMe, -OMe and -OH groups as the substituents suggest that the acidity of the meso-phenyl substituent plays a key role in enhancing the hydrogen evolution activities during the catalytic processes.
- Beyene, Belete B.,Mane, Sandeep B.,Hung, Chen-Hsiung
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p. H481 - H487
(2018/07/06)
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- Selective production of aromatic aldehydes from heavy fraction of bio-oil via catalytic oxidation
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High value-added aromatic aldehydes (e.g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H2O2) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS 4)) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS4). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS 4)/H2O2 was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS4)/H2O2 system.
- Li, Yan,Chang, Jie,Ouyang, Yong,Zheng, Xianwei
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supporting information
p. 1654 - 1658
(2014/07/07)
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- Synthesis and cancer cell cytotoxicity of water-soluble gold(III) substituted tetraarylporphyrin
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The synthesis of novel substituted gold(III) tetraarylporphyrins with aqueous solubility has been carried out. The analogs ClAuTPP(CH 3Py+?I-), ClAuTCPPNa, ClAuTPPCO 2Na, ClAuTSPPNa and ClAuTPPNH2?HCl were evaluated for their in vitro cytotoxic activity against sarcoma 180 mouse tumor and SGC-7901 human gastric cancer cell line panel. Compound ClAuTCPPNa exhibited significant growth inhibitory properties against sarcoma 180 mouse tumor and SGC-7901 human gastric cancer cell examined, and afforded IC50 values 2?HCl was an effective inhibitor of sarcoma 180 mouse tumor and SGC-7901 human gastric cancer cell growth, but generally less effective as a cytotoxic agent. Thus, the substituted gold(III) porphyrin ClAuTCPP-Na + and ClAuTPPNH2?HCl with aqueous solubility were regarded as useful lead compounds for further structural optimization.
- Sun, Liang,Chen, Huasheng,Zhang, Zonglei,Yang, Qian,Tong, Haibo,Xu, Aihua,Wang, Cunde
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- Phase-transfer of porphyrins by polypeptide-containing hyperbranched polymers and a novel iron(iii) porphyrin biomimetic catalyst
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Water-soluble porphyrins can be phase transferred by the hyperbranched multiarm copolymer PEI-PZLys; good catalytic activities and recyclabilities were observed for oxidation catalyzed by the encapsulated porphyrins. The Royal Society of Chemistry 2009.
- Ren, Qi-Zhi,Yao, Yuan,Ding, Xiao-Jian,Hou, Zong-Sheng,Yan, De-Yue
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supporting information; experimental part
p. 4732 - 4734
(2010/01/16)
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- Synthesis, photophysical studies and anticancer activity of a new halogenated water-soluble porphyrin
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A water-soluble halogenated porphyrin, namely 5,10,15,20-tetrakis(2-chloro- 3-sulfophenyl)porphyrin (TCPPSO3H), was prepared and evaluated as sensitizer for photodynamic therapy (PDT). Photophysical properties of TCPPSO3H, such as high photostability, long triplet lifetime and high singlet oxygen quantum yield suggest high effectiveness of this class of halogenated porphyrins in PDT. TCPPSO3H is non-toxic in the dark and causes a significant photodynamic effect examined against MCF7 (human breast carcinoma), SKMEL 188 (human melanoma) and S91(mouse melanoma) cell lines upon red light irradiation (cutoff 3H reached plateau at 120 min and was the highest for S91, 20% lower for MCF7 and 70% lower for SKMEL 188. Our results show that this halogenated water-soluble porphyrin is an efficient photosensitizer and reveal the potential of this class of compounds as PDT agents.
- Dabrowski, Janusz M.,Pereira, Mariette M.,Arnaut, Luis G.,Monteiro, Carlos J. P.,Peixoto, Andreia F.,Karocki, Andrzej,Urbanska, Krystyna,Stochel, Grazyna
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p. 897 - 903
(2008/03/12)
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- New procedures for the synthesis and analysis of 5,10,15,20-tetrakis(sulphophenyl)porphyrins and derivatives through chlorosulphonation
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Tetrakisarylporphyrins are conveniently chlorosulphonated in high yields. These chlorosulphonyl compounds may be converted in high yield into sulphonic acid derivatives through reaction with a variety of nucleophiles so as to give, for example, the free sulphonic acid, a sulphonamide or a sulphonate ester.
- Rocha Gonsalves, Antonio M.d'A.,Johnstone, Robert A.W.,Pereira, Mariette M.,De SantAna, Alexandra M.P.,Serra, Armenio C.,Sobral, Abilio J.F.N.,Stocks, Paul A.
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p. 829 - 838
(2007/10/03)
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- Steric and Inductive Effects on the Basicity of Porphyrins and on the Site of Protonation of Porphyrin Dianions. Radiolytic Reproduction of Porphyrins and Metalloporphyrins to Chlorins and Phlorins
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A series of sulfonated, water-soluble, phenyl-substituted porphyrins has been prepared, containing halogen or alkyl groups in the ortho, di-ortho or para position.While the para-substituted compounds exhibited monomer-dimer behaviour, all the ortho and di-ortho substituted porphyrins were monomeric in aqueous solution at 0.1 mol dm-3 ionic strength.The proton basicities varied over a 105 range along the series, from the strongly basic tetra(4-methoxyphenyl) species to the weakly basic and less deformable sulfonated tetrakis(2,6-dichlorophenyl)porphyrin.Certain of these porphyrins and related metalloporphyrins were reduced by radiolytic methods in aqueous solutions.Pulse radiolysis studies provided the spectra fo the short-lived ?-radical anions and γ-radiolysis led to formation of stable chlorins and phlorins, the products of two-electron reduction and protonation at the β-pyrrole or at the meso postion, respectively.Whereas H2TPPS4 yields phlorin at all pH values, Zn(II)-, Al(III)-, In(III)- and Sn(IV)-TPPS4 form phlorins at high pH and by increased metal electronegativity. 2,6-Disubstitution at the phenyl rings diminishes the likehood of phlorin formation.These and other results indicate that electron withdrawal from the porphyrin ?-system enhances the ratio of phlorin/chlorin production.On the other hand, steric crowding around the meso position retards protonation at this site by preventing the geometric reorientation necessary for phlorin formation.
- Sutter, Thimothy P. G.,Rahimi, Rahmatollah,Hambright, Peter,Bommer, Jerry C.,Kumar, Manmohan,Neta, Pedatsur
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p. 495 - 502
(2007/10/02)
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- KINETICS AND MECHANISM OF THE SOLVOLYSIS OF TETRASULFONYL FLUORIDES - DERIVATIVES OF MESOTETRAPHENYLPORPHIN - IN CONCENTRATED SULFURIC ACID
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A method was developed for the determination of the effective rate constants (keff) for the substitution of fluorine by the OH group in one of the four sulfonyl fluoride groups in H2TFP(4-SO2F)4, H2TFP(3-CH3)4(4-SO2F)4, and H2TFP(4-CH3)4(3-SO2F)4 during their solvolysis in sulfuric acid.The forms of the porphyrin protonated twice at the nitrogen atoms participate in the reactions.The keff values were determined at sulfuric acid concentrations of 98.0-100.0 wt. percent H2SO4 and temperatures of 338-358 K and were converted to 373 K for comparison.In each case the reaction rate obeys a first-order equation in the tetrasulfonyl fluoride.Possible mechanism of sulfuric acid solvolysis are proposed on the basis of the dependence of log keff373 on the acidity function of the medium (-H0373).The Hammett ? constant for the phenyl substituted by tri-(4-fluorosulfonylphenyl)porphinyl protonated twice at the nitrogen atoms was found to be 0.27.
- Shchukina, M. V.,Gnedin, B. G.,Berezin, B. D.
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p. 1987 - 1994
(2007/10/02)
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- The State of Tetrasulphophenylporphin in Acid Aqueous and Aqueous Alcoholic Solutions
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The state of tetra-(p-sulphophenyl)porphin in acid aqueous and aqueous alcoholic solutions has been investigated spectrophotometrically.It is shown that the basicity constants pK3,4 of the porphyrin decrease from 9.8 +/- 0.1 in water to 6.6. +/- 0.3 in 60percent alcohol.It has been established that the porphyrin is highly associated in aqueous perchloric acid solutions at pH 1.5 and that the addition of alcohol does not favour association.
- Berezin, B. D.,Golubchikov, O. A.,Klopova, L. V.,Andrianov, V. G.,Sheinin, V. B.
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p. 1159 - 1162
(2007/10/02)
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