Shirley Nakagaki

Federal University of Paraná | UFPR · Department of Chemistry

In this work, zinc oxide with different morphologies and textural properties were prepared and sensitized with metalloporphyrins (MPs) aiming to improve its solar energy harvesting capability for H2 production by water splitting under sunlight (a 300 W Xe/Hg lamp). An anionic iron(III)porphyrin and a cationic manganese(III)porphyrin were immobilize...

In this work, some of the synthesis methods already reported for aluminum(III) hydroxide polymorphs with layered structure like gibbsite are revisited. Gibbsite was synthesized with high purity and yield by a simple route developed from modifications of a heating method proposed in the literature, making it possible to prepare gibbsite in regular g...

In recent decades, the increasing use of pesticides to improve food productivity has led to the release of effluents that contaminate the environment. To prepare a material that may help to treat effluents generated during agricultural practice, we used a new method based on the non-hydrolytic sol-gel route to obtain zinc photocatalysts in aluminop...

Layered hydroxide salts (LHS) are synthetic and natural materials with the general chemical composition M²⁺(OH)2−x(Am−)x/m (M²⁺ is a divalent cation, normally Mg²⁺, Ni²⁺, Zn²⁺, Ca²⁺, Cd²⁺, Co²⁺or Cu²⁺, and (Am−)x/m·nH2O is a hydrated counter-ion). In most of the cases, the LHS structures are based on the modification of the layered magnesium hydrox...

Manganese porphyrins are widely studied as catalysts for oxidation reactions of different organic substrates. In this work, we evaluate the catalytic activity of manganese complexes derived from meso‐tetrakis(2‐, 3‐, or 4‐pyridyl) porphyrin isomers, [Mn(TXPyP)]Cl (X = 2, 3, or 4), and the respective β‐octabrominated counter‐parts, [Mn(Br8TXPyP)], f...

The iron metalation of the known free‐base porphyrins H2P2 and H2P3, obtained by structural modification of the well‐known TPPF20 (H2P1) with galactose dendritic units, gave the corresponding iron(III) porphyrin complex FeP2 and the solid hybrid material FeP3S. Their synthesis, characterization and catalytic efficacy toward the oxidation of the org...

Iron-containing alumina materials were prepared by the non-hydrolytic sol-gel method in the presence of surfactants and their use as catalysts in the oxidation of hydrocarbons was studied. The solids were mesoporous, with large specific surface areas, > 250 m²/g for the solids treated at 500 °C, depending on the surfactant used (cetyltrimethylammon...

Two manganese(III) porphyrin complexes prepared with the tetra anionic free base porphyrin (Na4[H2(TDFSPP)]) and two different manganese(II) salts (manganese(II) acetate - MnP(OAc) complex and manganese(II) chloride - MnP(Cl) complex) were immobilized onto zinc hydroxide nitrate (ZHN), a layered hydroxide salt, and also into zinc oxide (ZnO), obtai...

Different solid catalysts were prepared by impregnation of tungsten species on commercial mesoporous silica. The resulting materials were characterized in order to elucidate their composition, properties and acidity. Moreover, the catalytic results were carefully studied, in an attempt to reach insights about the catalytic active species involved i...

DFT calculations were employed in order to gain insight about the mechanism of the oxidation reaction catalyzed by anionic iron(III) porphyrin ([Fe(TSPP)Cl]4−) with different counter ions (H+ and Na+) immobilized onto Zn4Al2(OH)12(CO3).4H2O layered double hydroxide. The immobilization of these porphyrinates was modelled by the construction of a LDH...

The synthetic versatility and the potential applications of porphyrins and analogues in different fields have aroused special interest in their study, especially to mimic biological systems, such as cytochrome P-450. The ability of the porphyrin tetrapyrrolic core to accommodate metal ions of varying charges can modulate the type of application of...

Poly(2-hydroxyethyl methacrylate)-based materials bearing porphyrinic units were prepared, characterized and their ability to inactivate Escherichia coli and Staphylococcus aureus bacteria was evaluated. Porphyrins containing methacrylate moieties were prepared by the sequential nucleophilic substitution of the para-fluorine atoms in 5,10,15,20-tet...

The post-functionalization of 5,10,15-tris(1-methylpyridinium-4-yl)-20-(pentafluorophenyl)porphyrin tri-iodide, known as a highly efficient photosensitizer (PS) for antimicrobial photodynamic therapy (aPDT), in the presence of 3- or 4-mercaptobenzoic acid, afforded two new tricationic porphyrins with adequate carboxylic pending groups to be immobil...

The development of selective, efficient, and recoverable/reusable catalysts for oxidation reactions has become one of the main challenges of modern chemistry. Considering our interest in efficient catalytic systems based on porphyrin (Por) and phthalocyanine (Pc) coordination polymers, we report here the synthesis, characterization and catalytic ac...

The protection of carbonyl groups that produce acetal products is a key reaction in fine chemistry due to the high reactivity of aldehydes and ketones in certain media. This process can be catalyzed by protic or Lewis acids. Since metalloporphyrins often possess free axial positions in the central metal, they can be applied as Lewis acid catalysts,...

This paper reports the use of two layered hydroxide salts (LHS) (zinc hydroxide nitrate – ZHN – Zn5(OH)8(NO3)2·2H2O, and zinc hydroxide chloride – ZHC – Zn5(OH)8Cl2·H2O) as catalysts for brilliant green (BG) organic dye bleaching, using hydrogen peroxide as oxidant. The LHS were prepared by precipitation reaction between an aqueous solution of zinc...

New microporous polymer networks, constructed by a nucleophilic substitution reaction between twodifferent porphyrins and metalloporphyrins are reported. The meso-tetrakis-(pentafluorophenyl)porphyrin HP1 (monomer A1) and/or its manganese complex MP1 (monomer A2) was reacted with themeso-tetrakis-(3,4-dihydroxyphenyl)porphyrin HP2 (monomer B1) and/o...

Coordination Polymer-type materials obtained from the reaction of 5,10,15,20-tetrakis[2,3,5,6-tetrafluoro-4-(4-pyridylsulfanyl)phenyl]porphyrin (H2P1) and 5,10,15,20-tetrakis(4-pyridyl)porphyrin (H2P2) with copper(II) and zinc(II) acetate are reported. Materials show catalytic activity for the oxidation of catechol comparable to that of the copper...

Complexes of porphyrins and of other similar tetrapyrrolic macrocycles are extensively explored as catalysts for different chemical processes, and the development of solid catalysts for heterogeneous processes using molecules with the ability to act as multifunctional catalysts in one-pot reactions is increasing and can lead to the wider use of thi...

Solid magnetic nanoparticles (magnetite = Mag) composed of Fe3O4 and magnetite coated with silica (Fe3O4/SiO2 = Mag/Si) were prepared from inexpensive starting materials. The catalytic activity of the solids was investigated for palmitic acid esterification with methanol under solvothermal conditions. Both pure Fe3O4 (Mag) and silica-coated (Mag/Si...

Synthetic metalloporphyrins (MP) have been widely investigated as catalysts in oxidation reactions, mainly regarding the mimicking of cytochrome P-450 enzymes, both in homogeneous and heterogeneous catalysis studies, showing promising results. Heterogeneous catalysis has advantages over the homogeneous one, like the possibility of the catalyst reus...

The spin-dependent electronic transport properties of metal-(dcdmp)2 (M = Cu, Au, Co, Ni; dcdmp = 2,3-dicyano-5,6-dimercaptopyrazyne) molecular wires were investigated by density functional theory combined nonequilibrium Green's function method (DFT-NEGF). Our results show that the spin-dependent transport properties of the Metal-(dcdmp)2 molecular...

This work describes the immobilization of neutral and cationic Mn porphyrins (MnP) on magnetic SBA-15 mesoporous silica. XRD patterns, TEM images and N2 adsorption-desorption analyses showed that the prepared solids had high surface areas and homogeneous porosities, confirming the presence of magnetite (Mag), which is a key feature for fast and eas...

Two isostructural metalloporphyrin framework solids have been synthesized. Both frameworks contains manganese(III) metal complexes of trans-dicarboxylateporphyrins whose peripheralcarboxylates coordinate the edges of tetrahedral Zn4O+6 clusters; the two metalloporphyrins explored are Mn(III) and Co(II). The cubic interpenetrated frameworks have 72%...

Several functional hybrid materials have been reported as immobilized porphyrin derivatives in various organic and inorganic host materials (polymers, mineral clays, silica, etc.), with potential applications in various fields, such as photochemistry, electrochemistry and heterogeneous catalysis. Layered double hydroxides (LDHs), commonly known as...

Unsymmetric porphyrins, containing both pentafluorophenyl (PFP = A) and 3,4-dimethoxyphenyl (DMP = B) substituents at the meso positions, were prepared using Lindsey's methodology. The isomeric trans-A2B2 (P1) and cis-A2B2 (P2) porphyrins together with the tris(pentafluorophenyl)porphyrin A3B (P3) were isolated using chromatography. The porphyrins...

The preparation of hydrozincite in the presence of titanium, followed by the immobilization of two different metalloporphyrins, a positively charged iron porphyrin and a negatively charged manganese por-phyrin, is reported. Both metalloporphyrins were immobilized separately and then simultaneously in the same solid support. The resulting solids wer...

Density functional theory (DFT) calculations were performed to study the interaction between three dehydrated porphyrinates anions after the intercalation between Zn2Al layered double hydroxide layers, reported experimentally. A good agreement was obtained for the unit cell parameters and an analysis of the simulation approaches was conducted for t...

The immobilization of cationic manganese porphyrins (MnP) over the surface of a magnetic hexagonal HMS silica (HMS-Mag) produced a solid with high surface area and relatively homogeneous pores. Given the presence of the magnetite, the catalysts are easily recovered and reused without loss of mass. The MnP immobilization explored the strong interact...

The synthesis and structural characterization of novel MOF-type materials obtained from the reaction of 5,10,15,20-tetrakis[2,3,5,6-tetrafluoro-4-(4-pyridylsulfanyl)phenyl]porphyrin (H2P1) and 5,10,15,20-tetrakis(4-pyridyl)porphyrin (H2P2) with copper(II) acetate is reported. The new material CuP1S shows high heterogeneous catalytic activity in the...

Sodium gordaite (NaG - NaZn4(OH)6(SO4)Cl·6H2O) was synthesized, characterized and the intercalated sodium cations (in hydrated state) of NaG were replaced by lithium where the basal parameter was altered from 13.03 Å to 17.84 Å. The obtained lithium gordaite (LiG) was used as support for the immobilization of a cationic manganese(III) porphyrin (Mn...

A family of niobia (Nb2O5) functionalized SBA-15 solid catalysts have been prepared via wet impregnation with NbCl5 (2–32 wt% Nb) and subsequent thermal processing, for application in the acid catalyzed esterification of propanoic acid with methanol. Bulk and surface physicochemical characterization revealed that highly dispersed niobia species pre...

New materials obtained through the incorporation of meso-tetraarylporphyrins, bearing phenyl or pentafluorophenyl groups at the meso positions with or without acid groups, in chitosan films have been prepared and characterized in detail. The efficiency of these porphyrinic-chitosan films (PS-CF) to prevent Listeria innocua attachment and subsequent...

With the predicted depletion of crude oil reservoirs in the next decades as well the need for developing renewable energy and sustainable production processes, low-carbon technologies will have a crucial role in securing energy supplies for future generations and offsetting the environmental impact of fossil fuels production and use. In this scenar...

In this work, solid catalysts were prepared by the heterogenization of Mn porphyrins (MnP) on mesoporous silica SBA-15 by two simple strategies: 1) immobilization of the three cationic isomers of Mn(III) N-methylpyridiniumporphyrins (MnTM-X-PyPCl5, X = 2, 3, 4) on mesoporous silica SBA-15 by electrostatic interaction; and 2) anchoring of the three...

The catalytic efficiency and selectivity of a series of manganese(III) complexes of meso-tetrakis(pentafluorophenyl)porphyrin H2(TPFPP) derivatives bearing one to four ethylene glycol moieties are compared in the oxidation of cis-cyclooctene and cyclohexane in the presence of H2O2 at ambient temperature. The results show that the catalysts’ perform...

Layered materials are a very interesting class of compounds obtained by stacking of two-dimensional layers along the basal axis. A remarkable property of these materials is their capacity to interact with a variety of chemical species, irrespective of their charge (neutral, cationic or anionic). These species can be grafted onto the surface of the...

In this work a vanadium(III)-based catalyst was synthesized, characterized by thermogravimetric analysis, electron paramagnetic resonance (EPR), powder X-ray diffraction (PXRD) and FTIR spectroscopy, and its activity was evaluated during fatty acids esterification with methanol. The solid catalyst was monitored during the catalyzed reactions, condu...

A novel third-generation metalloporphyrin, chloro-5,10,15,20-tetrakis-(3′-bromine-4′-methoxyphenyl)-2,3,7,8,12,13,17,18-octabromoporphyrinatomanganese(iii), [MnIIIBr12T4(-OMe)PPCl], designated as MnBr12Por, was synthesized and characterized. The catalytic activity of the new manganese porphyrin was investigated in the oxidation of cyclohexane, adam...

This work describes the synthesis and characterization of a novel third-generation catalyst 5,10,15,20-tetrakis-(4′-bromine-3′,5′-dimethoxyphenyl)-2,3,7,8,12,13,17,18-octabromoporphyrinatomanganese chloride [MnIIIBr12T3,5DMPP]Cl (Cat.2). The catalytic activity of Cat.2 in cyclohexane, adamantane, and n-hexane oxidation by iodosylbenzene (PhIO) or i...

Synthetic strategies that comply with the principles of green chemistry represent a challenge: they will enable chemists to conduct reactions that maximize the yield of products with commercial interest while minimizing by-products formation. The search for catalysts that promote the selective oxidation of organic compounds under mild and environme...

Synthetic metalloporphyrins can oxidize organic substrates efficiently and selectively in the presence of different oxygen donors. In an attempt to propose new catalytic systems to treat industrial effluents, researchers have recently turned their attention to the performance of metalloporphyrin-based catalysts in bleaching reactions of organic dye...

This work employed [5,10,15,20-tetrakis-(pentafluorophenyl)porphyrin] ([H 2 (TPPF 20)], H 2 P1) as the platform to prepare a tetrasubstituted galactodendritic conjugate porphyrin (H 2 P3). After metalation with excess copper(II) acetate, H 2 P3 afforded a new solid porphyrin material, Cu 4 CuP3S. This work also assessed the ability of the copper(II...

Inspired by the efficiency and selectivity of the reactions catalyzed by cytochrome P-450, in recent years researchers have made great efforts to develop synthetic routes that afford new porphyrins with different structures. Synthetic metalloporphyrins are catalysts that can efficiently insert oxygen and other atoms such as nitrogen and sulfur in h...

This work employed [5,10,15,20-tetrakis(pentafluorophenyl)porphyrin] ([H-2(TPPF20)], H(2)P1) as the platform to prepare a tetrasubstituted galactodendritic conjugate porphyrin (H(2)P3). After metalation with excess copper(II) acetate, H(2)P3 afforded a new solid porphyrin material, Cu(4)CuP3S. This work also assessed the ability of the copper(II) c...

The oxidation of organic substrates via catalytic routes is an important class of reactions to produce industrial input materials such as epoxides, alcohols, and ketones. Metalloporphyrins display recognized catalytic activity that mimics oxidation processes in living organisms. Their immobilization in different inert supports allows their recovery...

The preparation, characterization, and application in oxidation reactions and antibacterial activity of new biomimetic heterogeneous materials are reported. Brazilian Sao Simao kaolinite has been functionalized with Fe(III)-[meso-tetrakis(tetracarboxyphenyl)porphinato], [FeTCPP]. Clay functionalization with FeTCPP was confirmed by the amide bands o...

Considering the versatility of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPPF20) to react with nucleophiles we highlight here the synthesis and characterization of several mono- and tetra-thiocarboxylate derivatives. The selective displacement of the para-fluorine groups in TPPF20 by thiocarboxylic acids demonstrates that TPPF20 is an ideal...

Metalloporphyrins effectively catalyze C-H bond functionalization, including C-O (hydroxylation), C-N (amination), and C-C bond formation (carbene insertion). Over the last 20 years, numerous papers have reported that these complexes display catalytic effi-ciency and selectivity (regioselectivity and enantioselectivity) in solution (homogeneous cat...

The catalytic activity of two manganese(II) complexes, [MnL1(H2O)](ClO4)2 (1) and [MnL2]ClO4 (2) N,O-donor L1 = N,N,N′-tris(2-methylpyridyl)-N′-hydroxyethyl-ethylenediamine and L2 = N-(2-hydroxybenzyl)-N,N′-bis(2-methylpyridyl)-N′-hydroxyethyl-ethylenodiamine in the epoxidation of alkenes was investigated in acetonitrile:dichloromethane mixtures at...

We reacted [meso-tetrakis(pentafluorophenyl) porphyrin] with ethylene glycol to obtain porphyrins substituted with one to four hydroxyalkyloxy groups at position 4 of the meso-aryl groups. We then inserted iron(III) or manganese(III) into the mono-and tetra-substituted free-base derivatives, which afforded the corresponding metalloporphyrin complex...

Bioenergy Research: Advances and Applications, (2014) 513pp. 978-0-444-59561-4

The synthetic versatility and the potential application of metalloporphyrins (MP) in different fields have aroused researchers' interest in studying these complexes, in an attempt to mimic biological systems such as cytochrome P-450. Over the last 40 years, synthetic MPs have been mainly used as catalysts for homogeneous or heterogeneous chemical r...

We prepared a free base porphyrin (HP) containing hydroxy and methoxy groups in the mesophenyl substituents of the porphyrin ring. We then inserted Mn(III) ion into the resulting HP, to obtain MnP. We used silica synthesized by the sol–gel process to immobilize the MnP in either acidic or basic medium, which afforded the solids MnPA and MnPB, respe...

In this paper we report the immobilization of different cationic and neutral metalloporphyrins (MPs) on silica-coated Fe3O4 nanoparticles, obtained by basic hydrolytic sol–gel process. We characterized the MP-immobilized materials by UV–vis spectroscopy (UV–vis), X-ray diffraction (XRD), infrared spectroscopy (FTIR), scanning electron microscopy (S...

The conversion of lauric acid and fatty acid mixtures to methyl esters was investigated using bismuth-containing solid catalysts obtained from Bi2O3. When the reaction was carried out at 140 °C for 2 h using a methanol:fatty acid molar ratio of 2:1 and 5 wt % of Bi2O3 in relation to the mass of fatty acids, conversions up to 87 wt % were achieved e...

The raw clay minerals kaolinite and halloysite were calcined at controlled temperature and time, to obtain metakaolinite and metahalloysite, respectively. The resulting materials were used as supports for the anionic iron(III) porphyrin [Fe(TDFSPP)] (FePor) and found that only metahalloysite is adequate for FePor immobilization, although the FePor...

Molybdenum-containing silica easily synthesized by the sol–gel process was evaluated as catalyst for heterogeneous esterification reaction of fatty acids using methanol and ethanol. The molybdenum content depended on the conditions employed during the synthesis. The solids were characterized by X-ray powder diffraction, textural analysis, X-ray pho...

Raw kaolinite was modified with triethanolamine (TEA), in an attempt to create a new support for the immobilization of metalloporphyrins. Anionic metalloporphyrins containing Fe(3+) or Mn(3+) as metallic centers were immobilized on the prepared support, and the obtained solids were characterized by Fourier-transform infrared (FTIR) spectroscopy, X-...

Sodium bismuthate dihydrate and two species derived from its thermal treatment were investigated as catalysts for soybean oil methanolysis and, regardless of the type of solid used, ester yields always above 76 wt% were obtained. After a single reaction course, both liquid and solid phases were characterized using several analytical methods such as...

The preparation and characterization of the metalloporphyrins [Fe(TAPP)]Cl, 5,10,15,20-tetrakis(acetalphenyl porphyrin) iron(III) chloride, and [Mn(TAPP)]Ac, 5,10,15,20-tetrakis (acetalphenyl porphyrin) manganese(III) acetate and of the solids obtained by their heterogenization in silica obtained by the sol-gel process in acidic and basic media are...

The development of alternative methods of biodiesel production still remains a major priority of the biofuel industry. In this work, the catalytic activity of anhydrous and insoluble sodium tungstate (Na2WO4) and its heterogenized form in silica (Na2WO4/SiO2) in soybean oil methanolysis was studied. The sol–gel process was conducted by both the aci...

This work describes the immobilization of an anionic iron(III) porphyrin (FePor) family on zinc hydroxide chloride (ZHC), a layered hydroxide salt prepared by reacting an aqueous zinc chloride solution with an ammonium hydroxide solution. The FePor immobilization was performed at room temperature under magnetic stirring, under air atmosphere, of ea...

An Mg–Al layered double hydroxide containing intercalated NO3− anions (LDH-N) was synthesized and subsequently submitted to a reaction with triethanolamine as modifying agent (LDH-TEA). A neutral iron(III) porphyrin was immobilized onto both solids LDH-N and LDH-TEA, and the catalytic activity of the resulting FePor-LDH-N and FePor-LDH-TEA was eval...

This paper is the first report on the immobilization of an anionic iron(III) porphyrin family on zinc hydroxide nitrate (ZHN), a layered hydroxide salt. ZNH was prepared by means of a precipitation reaction between a zinc nitrate solution and ammonium hydroxide. Two immobilization systems were investigated, namely magnetic stirring at room temperat...