Relevant bibliographies by topics / Cobalt porphyrin / Journal articles

Journal articles on the topic 'Cobalt porphyrin'

To see the other types of publications on this topic, follow the link: Cobalt porphyrin.
Author: Grafiati
Published: 10 December 2022
Last updated: 29 January 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Cobalt porphyrin.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

FUKUZUMI, SHUNICHI, and SOUTA NOURA. "Cobalt(III) Porphyrin-catalysed Hydride Reduction of 10-Methylacridinium ion and Hydrometallation of Alkenes and Alkynes by Tributyltin Hydride." Journal of Porphyrins and Phthalocyanines 01, no. 03 (July 1997): 251–58. http://dx.doi.org/10.1002/(sici)1099-1409(199707)1:3<251::aid-jpp24>3.0.co;2-p.

Full text
Abstract:
Cobalt(III) tetraphenylporphyrin catalyses a hydride transfer reaction from tributyltin hydride to 10-methylacridinium ion via the formation of hydridocobalt(III) tetraphenylporphyrin, which is the rate-determining step, followed by facile hydride transfer from the hydridocobalt(III) porphyrin to 10-methylacridinium ion in acetonitrile. Tributyltin hydride is also effective for the hydrometallation of alkenes and alkynes with cobalt(III) tetraphenylporphyrin to yield the corresponding organocobalt(III) porphyrins regioselectively. The hydrometallation is suggested to proceed via the hydride transfer from tributyltin hydride to cobalt(III) tetraphenylporphyrin to give the hydridocobalt(III) porphyrin, followed by the hydrogen transfer from hydridocobalt(III) porphyrin to alkenes and alkynes to yield the corresponding organocobalt(III) porphyrins. The regioselectivities are consistent with the stabilities of radicals generated by the hydrogen transfer from hydridocobalt(III) porphyrin to alkenes and alkynes. The rates of the electrophilic cleavage of cobalt-carbon bonds of organocobalt(III) porphyrins by trifluoroacetic acid in MeCN are also reported.
APA, Harvard, Vancouver, ISO, and other styles
2

YUASA, MAKOTO, BEAT STEIGER, and FRED C. ANSON. "Hydroxy-substituted Cobalt Tetraphenylporphyrins as Electrocatalysts for the Reduction of O2." Journal of Porphyrins and Phthalocyanines 01, no. 02 (April 1997): 181–88. http://dx.doi.org/10.1002/(sici)1099-1409(199704)1:2<181::aid-jpp22>3.0.co;2-r.

Full text
Abstract:
The possible effects of the electron-donating properties of p-hydroxyphenyl groups on the catalytic activity of cobalt porphyrins toward the electro-reduction of O 2 were explored with three cobalt porphyrins having p-hydroxyphenyl substituents in the meso position of the porphyrin ring. The porphyrins were examined as electrocatalysts adsorbed on the surfaces of pyrolytic graphite electrodes in aqueous solution and as homogeneous catalysts dissolved in methanolic solutions. The adsorbed molecules exhibited a higher catalytic activity than those in solution and accomplished the reduction of a portion of the O 2 molecules reaching the electrode to H 2 O . However, the four-electron reduction was indirect, with H 2 O 2 being formed as an intermediate that was subsequently reduced. Although the introduction of the electron-donating p-hydroxyphenyl substituents on the porphyrin ring altered the catalytic activity of the cobalt porphyrins, the effect was not as great as can be obtained by coordinating ruthenium (II) complexes to π-accepting ligands in the meso position of the porphyrin ring.
APA, Harvard, Vancouver, ISO, and other styles
3

Khusnutdinova, Diana, Anna M. Beiler, Brian L. Wadsworth, Sylvia K. Nanyangwe, and Gary F. Moore. "Vibrational structure analysis of cobalt fluoro-porphyrin surface coatings on gallium phosphide." Journal of Porphyrins and Phthalocyanines 22, no. 06 (June 2018): 461–66. http://dx.doi.org/10.1142/s1088424618500906.

Full text
Abstract:
Grazing angle attenuated total reflectance Fourier transform infrared (GATR–FTIR) spectroscopy is used to characterize chemically modified gallium phosphide (GaP) surfaces containing grafted cobalt(II) porphyrins with 3-fluorophenyl substituents installed at the meso-positions. In these hybrid constructs, porphyrin surface attachment is achieved using either a two-step method involving coordination of cobalt fluoro-porphyrin metal centers to nitrogen sites on an initially applied thin-film polypyridyl surface coating, or via a direct modification strategy using a cobalt fluoro-porphyrin precursor bearing a covalently bonded 4-vinylphenyl surface attachment group at a [Formula: see text]-position. Both surface-attachment chemistries leverage the UV-induced immobilization of alkenes but result in distinct structural connectivities of the grafted porphyrin units and their associated vibrational spectra. In particular, the in-plane deformation vibrational frequency of metalloporphyrin components in samples prepared via coordination to the polymeric interface is characterized by an eight wavenumber shift to higher frequencies compared to that measured on metalloporphyrin-modified surfaces prepared using the one-step attachment method. The more rigid ring structure in the polymeric architecture is consistent with coordination of porphyrin cobalt centers to pyridyl-nitrogen sites on the surface graft. These results demonstrate the use of GATR–FTIR spectroscopy as a sensitive tool for characterizing porphyrin-modified surfaces with absorption signals that are close to the detection limits of many common spectroscopic techniques.
APA, Harvard, Vancouver, ISO, and other styles
4

Subedi, Dili R., Youngwoo Jang, Ashwin Ganesan, Sydney Schoellhorn, Ryan Reid, Guido F. Verbeck, and Francis D’Souza. "Donor-acceptor conjugates derived from cobalt porphyrin and fullerene via metal-ligand axial coordination: Formation and excited state charge separation." Journal of Porphyrins and Phthalocyanines 25, no. 05n06 (April 17, 2021): 533–46. http://dx.doi.org/10.1142/s1088424621500449.

Full text
Abstract:
Two types of cobalt porphyrins, viz., meso-tetrakis(tolylporphyrinato)cobalt(II), (TTP)Co (1), and meso-tetrakis(triphenylamino porphyrinato)cobalt(II), [(TPA)4P]Co, (2) were self-assembled via metal-ligand axial coordination of phenyl imidazole functionalized fulleropyrrolidine, ImC[Formula: see text] to form a new series of donor–acceptor constructs. A 1:2 complex formation with ImC[Formula: see text] was established in the case of (TTP)Co while for [(TPA)4P]Co only a 1:1 complex was possible to positively identify. The binding constants [Formula: see text] and [Formula: see text] for step-wise addition of ImC[Formula: see text] to (TTP)Co were found to be 1.07 × 105 and 3.20 × 104 M[Formula: see text], respectively. For [(TPA)4P]Co:ImC[Formula: see text], the measured [Formula: see text] values was found to be 6.48 × 104 M[Formula: see text], slightly smaller than that observed for (TTP)Co. Although both cobalt porphyrins were non-fluorescent, they were able to quench the fluorescence of ImC[Formula: see text] indicating occurrence of excited state events in the supramolecular donor-acceptor complexes. Electrochemistry coupled with spectroelectrochemistry, revealed the formation of cobalt(III) porphyrin cation instead of a cobalt(II) porphyrin radical cation, as the main product, during oxidation of phenyl imidazole coordinated cobalt porphyrin. With the help of computational and electrochemical results, an energy level diagram was constructed to witness excited state photo-events. Competitive energy and electron transfer from excited CoP to coordinated ImC[Formula: see text], and electron transfer from Im1C[Formula: see text]* to cobalt(II) porphyrin resulting into the formation of PCo[Formula: see text]:ImC[Formula: see text] charge separated state was possible to envision from the energy diagram. Finally, using femtosecond transient absorption spectroscopy and data analysis by Glotaran, it was possible to establish sequential occurrence of energy transfer and charge separation processes. The lifetime of the final charge separated state was [Formula: see text] 2 ns. A slightly better charge stabilization was observed in the case of [(TPA)4P]Co:ImC[Formula: see text] due to the presence of electron rich, peripheral triphenylamine substituents on the cobalt porphyrin.
APA, Harvard, Vancouver, ISO, and other styles
5

YUAN, HONGPING, and L. KEITH WOO. "Synthesis and Characterization of Thiol-Derivatized Porphyrins and Metalloporphyrin complexes." Journal of Porphyrins and Phthalocyanines 01, no. 02 (April 1997): 189–200. http://dx.doi.org/10.1002/(sici)1099-1409(199704)1:2<189::aid-jpp23>3.0.co;2-g.

Full text
Abstract:
A series of thiol-derivatized porphyrins and the corresponding cobalt and zinc complexes were synthesized from 5-(p-aminophenyl)-10,15,20-triphenylporphyrin ( H 2 TPP - NH 2), and 5α,15α-bis(o-aminophenyl)porphyrin ( H 2 DPE - ( NH 2)2). These derivatized porphyrins have a different number of thiol appendages attached via amide linkages at different locations. The thiol-derivatized porphyrins made from H 2 TPP - NH 2, H 2 TPP - NHC ( O )( CH 2) n SH ( n = 2, 4, 5, 10), have one alkyl-thiol appendage attached to the porphyrin through an amide linkage on the p-aminophenyl position. The derivatives made from H 2 DPE -( NH 2)2 have two alkyl-thiol appendages attached to the porphyrin through amide linkages on the o-aminophenyl positions on the same face of the porphyrin ring. These thiol-derivatized porphyrins are important adsorbates for the preparation of thiol–porphyrin monolayers on gold.
APA, Harvard, Vancouver, ISO, and other styles
6

Glazkova, Maria Е., Тatiana А. Аgeeva, Yuliya S. Rodina, and Oscar I. Koifman. "SPECTRAL INVESTIGATIONS OF COBALT PORPHYRINATES INTERACTION WITH RADICAL POLYMERIZATION INITIATORS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, no. 5 (May 21, 2019): 91–96. http://dx.doi.org/10.6060/ivkkt.20196205.6029.

Full text
Abstract:
The article presents the results of the kinetics study of the cobalt porphyrins interaction with radical polymerization initiators – benzoyl peroxide and lauryl peroxide – in solution by the spectrophotometric method. From disparate literature data, it is known that some metalloporphyrins can interact with benzoyl peroxide to form the tautomers of porphyrins – isoporphyrins. These compounds have a number of specific properties, for example, it can be catalysts of various processes. Perhaps the isoporphyrins formation is the reason for high activity of the initiating systems “cobalt porphyrin – benzoyl peroxide” in the polymerization of vinyl monomers. Cobalt(II)complexes of tetraphenylporphyrin, tetra-para-methoxyphenylporphyrin, 5,15-bis(4´-tert-butylphenyl)-3,7,13,17-tetramethyl-2,8,12,18-tetra-p-butylporphyrin were selected as the objects of this study. The influence of the porphyrin ligand structure on the formation of cobalt isoporphyrins was estimated. The interaction of cobalt (II) tetraphenylporphyrin and cobalt (II) tetra-para-methoxyphenylporphyrin with peroxides showed changes in the electronic absorption spectra of metalloporphyrins: deformation of the Soret band, reduction of the absorption band in the visible region, and the appearance of absorption bands in the near IR region. These changes are characteristic for metalloisoporphyrins. Data on the interaction of cobalt porphyrins with lauryl peroxide were obtained for the first time. The formation of isoporphyrins is possible with the different ratio of concentrations of reagents: with a lack of peroxide, with equimolar ratio, and also with a significant (100-fold) excess of peroxide. When 5,15-bis (4´-tert-butylphenyl)-3,7,13,17-tetramethyl-2,8,12,18-tetra-p-butylporphyrinate cobalt (II) reacted with peroxides, no isoporphyrinates were observed. The article presents the effective reaction rate constants of the cobalt isoporphyrinates formation at 25 °C. It is shown that the structure of both cobalt porphyrinates and organic peroxides affects the possibility and rate of isoporphyrins formation.
APA, Harvard, Vancouver, ISO, and other styles
7

Barbe, Jean-Michel, Fabien Burdet, Enrique Espinosa, Claude P. Gros, and Roger Guilard. "New insights into the synthesis of porphyrin-corrole and biscorrole systems." Journal of Porphyrins and Phthalocyanines 07, no. 05 (May 2003): 365–74. http://dx.doi.org/10.1142/s1088424603000471.

Full text
Abstract:
As in the case of porphyrins, the relatively easier synthesis of meso-substituted corroles compared to that of β-pyrrole substituted ones greatly limits the use of these latter derivatives. Here we show, for the synthesis of β-substituted biscorrole and porphyrin-corrole dyads, that a simple replacement of sodium hydrogen carbonate by sodium acetate in the final cyclisation step of the a,c-biladiene to the corrole ring, increases the yield by at least a factor of 3. This reaction can be extended to the synthesis of β-substituted monocorroles. Moreover, when cobalt acetate is added instead of the reoxidation step, a 34 to 63% yield in porphyrin-spacer- Co ( III ) corrole is obtained, thus avoiding isolation of the free-base and further metalation of this latter derivative. This “cyclisation-oxidation-metalation” reaction is of particular interest in the preparation of heterobimetallic species in porphyrin-corrole series. Indeed, it leads to the formation of the monocobalt derivative with the cobalt atom inside the corrole moiety allowing for the further insertion of a large variety of metals into the porphyrin macrocycle. Crystals of the monocobalt complex of a biphenylene bridged porphyrin-corrole derivative were obtained in the presence of pyridine and the structure was determined by X-ray diffraction analysis. The structure shows that only one pyridine molecule is bound to the cobalt centre in an exo position, thus indicating a strong steric hindrance from the porphyrin counterpart.
APA, Harvard, Vancouver, ISO, and other styles
8

Carlucci, Lucia, Gianfranco Ciani, Simona Maggini, Davide M. Proserpio, Fabio Ragaini, Emma Gallo, Marco Ranocchiari, and Alessandro Caselli. "Synthesis and characterization of new tetra-substituted porphyrins with exo-donor carboxylic groups as building blocks for supramolecular architectures: Catalytic and structural studies of their metalated derivatives." Journal of Porphyrins and Phthalocyanines 14, no. 09 (September 2010): 804–14. http://dx.doi.org/10.1142/s1088424610002641.

Full text
Abstract:
We report herein the synthesis of the porphyrins 5,10,15,20-tetrakis(4-carboxybiphenyl)-porphyrin (H2TCBP) and 5,10,15,20-tetrakis(4-carboxy-2,6-dimethylbiphenyl)porphyrin (H2TCDMBP) bearing diphenyl units on meso-positions, and of their cobalt and silver derivatives. The silver complexes of H2TCDMBP and of H2TCPP ( H2TCPP = 5 ,10,15,20-tetrakis(4-carboxyphenyl)porphyrin) were investigated by X-ray crystallography and their supramolecular organization elucidated. Co(TCBP) was reacted with copper formate, yielding a polymeric compound that showed a catalytic activity in the benzylic amination of hydrocarbons using arylazide as aminating agent.
APA, Harvard, Vancouver, ISO, and other styles
9

D'SOUZA, FRANCIS, YI-YING HSIEH, and G. R. DEVIPRASAD. "Electrochemical and Spectroelectrochemical Characterization of Water-soluble, β-Pyrrolebrominated Cobalt Porphyrins." Journal of Porphyrins and Phthalocyanines 02, no. 05 (October 1998): 429–37. http://dx.doi.org/10.1002/(sici)1099-1409(199807/10)2:4/5<429::aid-jpp117>3.0.co;2-8.

Full text
Abstract:
The electrochemical and spectroelectrochemical characterization of two water-soluble porphyrins, namely the tetrachloro salt of cobalt(II) tetrakis-(N-methyl pyridyl)-β-octabromoporphyrin, [( Br 8 TMPyP ) Co II] Cl 4, and the tetrasodium salt of cobalt(II) tetrakis-(4-sulfonatophenyl)-β-octabromoporphyrin, Na 4[( Br 8 TPPS ) Co II], under different pH conditions is reported. The investigated porphyrins are highly non-planar and electron-deficient owing to the presence of eight bromides at the β-pyrrole positions and the four meso-aryl substituents. The redox potentials corresponding to the first oxidation and first reduction are shifted positively compared with the redox potentials of the respective unbrominated porphyrin derivatives. Spectroelectrochemical studies reveal the formation of a cobalt(III) complex during the first oxidation of both cobalt porphyrins. The first reduction of Br 8 TPPS ) Co II]4− results in a cobalt(I) complex, while involvement of the peripheral N-methyl pyridyl groups in the case of Br 8 TMPyP ) Co II]4+ is suggested. The peak potentials of the first oxidation corresponding to a Co II/ Co III redox couple of both investigated compounds are found to be pH-dependent. Debromination of the β-pyrrole bromo substituents of Br 8 TMPyP ) Co II]4+ at more negative potentials is observed. The UV-vis spectrum obtained after bulk electrolysis of Br 8 TMPyP ) Co II]4+ at −1.0 V vs Ag / AgCl followed by reoxidation at 0.2 V indicates complete elimination of the bromo substituents of the porphyrin periphery.
APA, Harvard, Vancouver, ISO, and other styles
10

Intrieri, Daniela, Sergio Rossi, Alessandra Puglisi, and Emma Gallo. "Metal-porphyrin catalyzed aziridination of α-methylstyrene: Batch vs. flow process." Journal of Porphyrins and Phthalocyanines 21, no. 04-06 (April 2017): 381–90. http://dx.doi.org/10.1142/s1088424617500365.

Full text
Abstract:
This work describes the aziridination process of [Formula: see text]-methylstyrene by using electron poor aromatic azides in the presence of metal-based porphyrins as catalysts. Different ruthenium and cobalt-based porphyrins were successfully employed for the synthesis of [Formula: see text]-aryl aziridines performed under a traditional batch methodology and under continuous flow conditions. In general, yields obtained using ruthenium-based catalysts in a traditional batch process were higher than those observed when the reaction was performed under flow conditions. However, cobalt-based porphyrins showed better activities and short reaction times when employed in a flow system process. DFT calculations were also performed in order to understand the influence of substituents on the porphyrin ring in the aziridination process.
APA, Harvard, Vancouver, ISO, and other styles
11

Nasri, Soumaya, Mouhieddinne Guergueb, Jihed Brahmi, Youssef O. Al-Ghamdi, Florian Molton, Frédérique Loiseau, Ilona Turowska-Tyrk, and Habib Nasri. "Synthesis of New Cobalt(III) Meso-Porphyrin Complex, Photochemical, X-ray Diffraction, and Electrical Properties for Photovoltaic Cells." Molecules 27, no. 24 (December 13, 2022): 8866. http://dx.doi.org/10.3390/molecules27248866.

Full text
Abstract:
The present work describes the preparation and characterization of a new cobalt(III) porphyrin coordination compound named (chlorido)(nicotinoylchloride)[meso-tetra(para-chlorophenyl)porphyrinato]cobalt(III) dichloromethane monosolvate with the formula [CoIII(TClPP)Cl(NTC)]·CH2Cl2 (4). The single-crystal X-ray molecular structure of 4 shows very important ruffling and waving distortions of the porphyrin macrocycle. The Soret and Q absorption bands of 4 are very red-shifted as a consequence of the very distorted porphyrin core. This coordination compound was also studied by fluorescence and cyclic voltammetry. The efficiency of our four porphyrinic compounds—the H2TClPP (1) free-base porphyrin, the [CoII(TClPP)] (2) and [CoIII(TClPP)Cl] (3) starting materials, and the new Co(III) metalloporphyrin [CoIII(TClPP)Cl(NTC)]·CH2Cl2 (4)—as catalysts in the photochemical degradation was tested on malachite green (MG) dye. The current voltage of complexes 3 and 4 was also studied. Electrical parameters, including the saturation current density (Js) and barrier height (ϕb), were measured.
APA, Harvard, Vancouver, ISO, and other styles
12

Do, Minh N., Nadezhda M. Berezina, Mikhail I. Bazanov, Sabir S. Gyseinov, Mikhail M. Berezin, and Oscar I. Koifman. "Electrochemical behavior of a number of bispyridyl-substituted porphyrins and their electrocatalytic activity in molecular oxygen reduction reaction." Journal of Porphyrins and Phthalocyanines 20, no. 05 (May 2016): 615–23. http://dx.doi.org/10.1142/s1088424616500437.

Full text
Abstract:
The investigation of electrochemical properties of active layers containing 5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphine, [5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12, 18-tetraethylporphinato]cobalt(II), bispyridine[5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(III), [5,15-bis(pyrid-4-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(II) and bispyridine[5,15-bis(pyrid-4-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(III) in 0.1 M KOH aqueous solution has been carried out by cyclic voltammetry. The potential ranges of redox processes related to the transformation of the porphyrin macrocycle, pyridyl substituents and central metal have been established. The electrochemical parameters of oxygen electroreduction reaction (the half-wave potential — E[Formula: see text](O[Formula: see text]), the maximum potential — E[Formula: see text](O[Formula: see text]), the current density — j, the activation energy — Eact) have been determined. It was shown that all porphyrins exhibit the catalytic activity. The electroreduction process of oxygen on electrode with the porphyrin-ligand occurs via 2-electron mechanism to give hydrogen peroxide ion HO2-, and on ones with the cobalt porphyrins — via parallel-sequential pathway including 2-electron and 4-electron processes to give HO2-, OH-. The presence of pyridine axial ligands in Co-complexes leads to a significant increase of the electrocatalytic activity in molecular oxygen reduction reaction.
APA, Harvard, Vancouver, ISO, and other styles
13

James, B. R., G. G. Meng, J. J. Posakony, J. A. Ravensbergen, C. J. Ware, and K. A. Skov. "Porphyrins and Metalloporphyrins: Potential Hypoxic Agents." Metal-Based Drugs 3, no. 2 (January 1, 1996): 85–89. http://dx.doi.org/10.1155/mbd.1996.85.

Full text
Abstract:
Synthetic water-soluble porphyrins and their metalloporphyrin derivatives with Co(III), Cu(II), Ru(II) and Pt(II), containing various functional groups within the meso-positions of the porphyrin, were synthesised and evaluated as hypoxic agents, especially as cytotoxins and radiosensitisers. Cobalt complexes of the porphyrins containing positively charged methylpyridinium groups showed selective toxicity toward hypoxic Chinese Hamster Ovary (CHO) cells. The Co(III) complexes of the cationic and the anionic porphyrins are all weak radiosensitisers toward hypoxic cells, the highest sensitisation enhancement ratio (SER = 1.22, at 50 μM) being with a porphyrin complex containing a cis-arrangement of two nitro and two methylpyridinium meso-substituents. A copper complex of a tetracationic porphyrin showed slight radiosensitisation activity with an SER value of about 1.1. The other metalloporphyrins showed no hypoxic selectivity or radiosensitisation activity. In total, over 50 porphyrin free bases have been synthesised, of which half are water-soluble and have been metallated; thus, the chemistry is now in place for further development of water-soluble hypoxic agents.
APA, Harvard, Vancouver, ISO, and other styles
14

MATHEW, TESSYMOL, and SUNNY KURIAKOSE. "Cobalt(II) Porphyrins Supported on Crosslinked Polymer Matrix as Model Compounds." Journal of Porphyrins and Phthalocyanines 03, no. 04 (April 1999): 316–21. http://dx.doi.org/10.1002/(sici)1099-1409(199904)3:4<316::aid-jpp136>3.0.co;2-z.

Full text
Abstract:
Polymer-bound cobalt(II) porphyrins were studied for their dioxygen—binding capacity. Tetra—aminoporphyrins were anchored on a divinylbenzene (DVB)-crosslinked chloromethyl polystyrene network. The crosslinked, solid polymers were swelled in chloroform and the swollen polymers were used for the entire studies. Ortho-, meta- and para-substituted porphyrin systems were developed by adjusting the bonding position with the help of suitably substituted aminoporphyrins. The products were characterized by chemical and spectroscopic methods. Cobalt(II) complexes of polymeric porphyrins were synthesized and characterized by electronic and ESR spectral methods. The spectra gave evidence for the systematic variation of electronic properties in ortho, meta and para compounds and for the dioxygen-binding capacity of cobalt complexes. These results are discussed.
APA, Harvard, Vancouver, ISO, and other styles
15

Milaeva, Elena R., Yulia A. Gracheva, Dmitry B. Shpakovsky, Olga A. Gerasimova, Vladimir Yu Tyurin, and Valery S. Petrosyan. "Oleic acid peroxidation in the presence of metallo-porphyrins." Journal of Porphyrins and Phthalocyanines 07, no. 11 (November 2003): 719–24. http://dx.doi.org/10.1142/s1088424603000896.

Full text
Abstract:
The influence of free bases of meso-tetrakis(3,5-di-tert-butyl-4-hydroxy-phenyl)porphyrins and meso-tetraphenylporphyrins and their complexes of Co , Ni , Cu , Pt upon the radical chain oxidation of oleic acid as model substrates for lipid peroxidation has been studied. It was shown that the introduction of the antioxidative phenolic fragment into the porphyrin ring leads to the dual activity of phenolic porphyrins when compared with their tetraphenyl substituted analogues in substrate oxidation. Free base phenolic porphyrins and their nickel, copper, platinum complexes demonstrate acute inhibitory effect upon oleic acid peroxidation due to the key role of 2,6-di-tert-butylphenol moities, whereas cobalt porphyrin exhibits dual activity associated with the presence of both the redox active metal center and phenolic group.
APA, Harvard, Vancouver, ISO, and other styles
16

Peng, Zhi-Jie, Jiao Zhao, Lei Gu, Xuan-Long Sun, Hai-Lang Jia, Ming-Yun Guan, and Shuai-Shuai Ma. "S-Doped hierarchical graphene decorated with Co-porphyrins as an efficient electrocatalyst for zinc–air batteries." New Journal of Chemistry 44, no. 34 (2020): 14343–49. http://dx.doi.org/10.1039/d0nj03443f.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Blackburn, P. Thomas, Iram F. Mansoor, Kaitlyn G. Dutton, Alexei M. Tyryshkin, and Mark C. Lipke. "Accessing three oxidation states of cobalt in M6L3 nanoprisms with cobalt–porphyrin walls." Chemical Communications 57, no. 86 (2021): 11342–45. http://dx.doi.org/10.1039/d1cc04860k.

Full text
Abstract:
Pt2+-linked M6L3 nanoprisms with cobalt–porphyrin walls were prepared and their redox properties were evaluated, leading to the first time that cobalt–porphyrin nanocages have been characterized in CoI, CoII, and CoIII states.
APA, Harvard, Vancouver, ISO, and other styles
18

Imaoka, Takane, Toshio Takatsuka, and Kimhisa Yamamoto. "Catalytic dehalogenation enhanced by appending dendritic ligands on cobalt porphyrins." Journal of Porphyrins and Phthalocyanines 10, no. 08 (August 2006): 1066–70. http://dx.doi.org/10.1142/s1088424606000429.

Full text
Abstract:
The dehalogenation activities of cobalt porphyrin catalysts with dendritic phenylazomethine units on the meso-positions were studied. Tetrachloroethylene was used as a substrate. By applying samarium iodide as a reducing agent, the tetrachloroethylene conversion into trichloroethylene and dichloroethylene was observed in the presence of the cobalt porphyrin catalyst. The turnover frequency was 1.70 min−1 when a cobalt porphyrin connected with dendritic phenylazomethines (3 generations) was employed as the catalyst. While the turnover frequency was almost the same as that for a non-dendritic porphyrin catalyst (1.57 min−1 by cobalt tetraphenylporphyrin), a significant increase in the turnover frequency was observed when samarium (3.43 min−1) or terbium trifluoromethane sulfonate (8.57 min−1) binds to the phenylazomethine units of the dendrimer. Because these metal ions ( Sm 3+ or Tb 3+) are positioned in a space between the encapsulated catalytic center and the solvent phase, they can act as electron mediators that relay electrons from the reducing agent (samarium iodide) to the catalytic center (cobalt porphyrin). This facile electron transfer would provide an enhancement in the catalytic activity for the tetrachloroethylene reduction leading to dehalogenation.
APA, Harvard, Vancouver, ISO, and other styles
19

Baral, Ek Raj, Dongwook Kim, Sunwoo Lee, Myung Hwan Park, and Jeung Gon Kim. "Tin(IV)-Porphyrin Tetracarbonyl Cobaltate: An Efficient Catalyst for the Carbonylation of Epoxides." Catalysts 9, no. 4 (March 29, 2019): 311. http://dx.doi.org/10.3390/catal9040311.

Full text
Abstract:
Cationic tin(IV) porphyrins with tetracarbonyl cobaltates were synthesized, exhibiting bifunctional catalytic reactivity. The Lewis acidic tin-porphyrin center activated epoxides; concurrently, cobalt carbonyl anions efficiently opened epoxides and delivered carbonyl moieties. Thus, a series of β-lactones with a high synthetic value were obtained. This catalytic system showed excellent efficiency exceeding a turnover number of one thousand with a broad substrate scope. In addition, the presented tin porphyrin-based catalyst exhibited exclusive chemoselectivity to terminal epoxides over internal ones. The selective carbonylation of di-epoxides demonstrated the usefulness of these catalysts in the synthesis of complex molecular structures.
APA, Harvard, Vancouver, ISO, and other styles
20

Kuvshinova, Elizaveta M., Maria A. Bykova, Irina A. Vershinina, Olga V. Gornukhina, Tatyana V. Lyubimova, and Alexander S. Semeikin. "SYNTHESIS AND COORDINATION PROPERTIES OF COBALT COMPLEXES OF 5-PHENYL-2,3,7,8,12,18-HEXAMETHYL-13,17-DIETHYLPORPHYRIN AND ITS NITRO-SUBSTITUTED IN ORGANIC SOLVENTS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 61, no. 7 (June 18, 2018): 44. http://dx.doi.org/10.6060/ivkkt.20186107.5843.

Full text
Abstract:
5-Phenyl-2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin (1), 5-phenyl-10,20-dinitro-2,3,7,8,12,18-hexamethyl -13,17-diethylporphyrin (2), 5- (p-nitrophenyl) -2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin (3) weresynthesized. The kinetics of formation and dissociation of their cobalt complexes in pyridine and acetic acid was studied. It was found that the change in reactivity upon transition from porphyrin 1 to 2 during complexation in acetic acid is due to an increase in the degree of deformation of the tetrapyrrole aromatic nucleus and the electronic effect of nitro groups. This is manifested by a strong bathochromic shift of all absorption bands in electronic spectra. It is shown that the opposite effect of the deformation effect and the i-effect of nitro groups on the rate of the reaction of formation of metal porphyrin leads to an insignificant change in the kinetic parameters. In pyridine, which has weakly basic properties, the reaction rate increases sharply with the introduction of nitro groups at position of 10, 20 of the porphyrin core. This is due to the fact that the deviation of the tetrapyrrole macrocycle from planarity leads to an increase in the reaction rate. It was found that a spherical distortion of the planar structure of porphyrins (1-3) in the series 1<3<2 relatively slightly influence on the rate of dissociation of their cobalt complexes. Apparently, this is due to the fact that coordination of the cobalt cation leads to a more flat structure of the tetrapyrrole macrocycle and the electronic effects of the nitro groups is the main contribution to the rate of the dissociation reaction of porphyrins (1-3).Forcitation:Kuvshinova E.M., Bykova M.A., Vershinina I.A., Gornukhina O.V., Lyubimova T.V., Semeikin A.S. Synthesis and coordination properties of cobalt complexes of 5-phenyl-2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin and its nitro-substituted in organic solvents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 43-48
APA, Harvard, Vancouver, ISO, and other styles
21

Hou, Yueping, Yuanyuan Fang, Zhongping Ou, Liping Wang, Weijie Xu, and Karl M. Kadish. "Electrochemical characterization of β,β′-butanoporphyrins containing sterically hindered meso-2,6-dihalogenophenyl substituents and first-row transition metal ions in nonaqueous media." Journal of Porphyrins and Phthalocyanines 25, no. 05n06 (May 2021): 555–70. http://dx.doi.org/10.1142/s1088424621500450.

Full text
Abstract:
Six [Formula: see text],[Formula: see text]-butano substituted metalloporphyrins containing sterically hindered meso-dihalogenophenyl substituents and first-row transition metal ions were synthesized and their electrochemical and spectroelectrochemical properties were characterized in nonaqueous media. The investigated compounds have the general formula butano(Y2Ph)4PorM, where Por is a dianion of the porphyrin, M = Mn[Formula: see text]Cl, Fe[Formula: see text]Cl, Co[Formula: see text], Ni[Formula: see text], Cu[Formula: see text] or Zn[Formula: see text]and Y2Ph is a sterically hindered 2,6-F2Ph or 2,6-Cl2Ph group on each of the four meso-positions of the macrocycle. The electrochemistry of each porphyrin was examined in CH2Cl2 or pyridine containing 0.1 M tetra-[Formula: see text]-butylammonium perchlorate. The first one-electron reduction is metal-centered for the manganese(III), iron(III) and cobalt(II) porphyrins to generate the Mn(II), Fe(II) and Co(I) porphyrins, but it is porphyrin ring-centered for the other examined M(II) porphyrins to give porphyrin [Formula: see text]-anion radicals under the given solution conditions. The effect of the [Formula: see text],[Formula: see text]-butano and sterically hindered meso-Y2Ph substituents on redox potentials and electron transfer mechanisms are discussed and compared to what was previously reported for butano-substituted tetraarylporphyrins without hindered meso-substituents.
APA, Harvard, Vancouver, ISO, and other styles
22

Lysenko, Andrey B., Patchanita Thamyongkit, Izabela Schmidt, James R. Diers, David F. Bocian, and Jonathan S. Lindsey. "Diverse porphyrin dimers as candidates for high-density charge-storage molecules." Journal of Porphyrins and Phthalocyanines 10, no. 01 (January 2006): 22–32. http://dx.doi.org/10.1142/s1088424606000041.

Full text
Abstract:
Porphyrinic molecules have been shown to be viable candidates for a molecular-based information storage medium on the basis of redox activity. An optimal redox-based information storage medium requires a large charge density in the molecular footprint on the anchoring substrate. The use of dimeric versus monomeric architectures affords one route to achieving increased charge density without sacrificing surface cross sectional area. Towards this goal, a series of zinc and cobalt containing porphyrin dimers has been prepared and characterized. The interporphyrin linkages in the dimers include p-phenylene, ethynyl, 1,4-butadiynyl, and ethynylphenylethynyl joining porphyrin meso-positions; Crossley-type fusion bridging porphyrin β-positions, and Osuka-type triple fusions bridging one meso- and two β-positions. The electrochemical features of each dimer have been evaluated.
APA, Harvard, Vancouver, ISO, and other styles
23

Zhao, Huazhang, Yingyue Chang, and Chuan Liu. "Electrochemical behavior of electrodes modified with metalloporphyrin and multiwalled carbon nanotubes for the reduction of oxygen, proton and carbon dioxide." Journal of Porphyrins and Phthalocyanines 17, no. 04 (April 2013): 259–63. http://dx.doi.org/10.1142/s1088424612501507.

Full text
Abstract:
Iron porphyrin and cobalt porphyrin were respectively modified on glassy carbon (GC) electrodes together with multiwalled carbon nanotubes (MWCNTs), and the modified electrodes were characterized by X-ray photoelectron spectroscopy (XPS). Their electrochemical performance for the reduction of oxygen (O2) , proton (H+) and carbon dioxide (CO2) were respectively investigated and compared by cyclic voltammetry (CV). The results showed that iron porphyrin-MWCNT modified electrode always had a better performance than cobalt porphyrin-MWCNT modified electrode. It is proposed that iron porphyrin-MWCNT modified electrode will have promising application in electrochemical architectures like microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) for its good biocompatibility, easy availability, as well as excellent electrochemical performance.
APA, Harvard, Vancouver, ISO, and other styles
24

Zhu, Weihua, Yuanyuan Fang, Wei Shen, Guifen Lu, Ying Zhang, Zhongping Ou, and Karl M. Kadish. "Reductive dechlorination of DDT electrocatalyzed by synthetic cobalt porphyrins in N,N′-dimethylformamide." Journal of Porphyrins and Phthalocyanines 15, no. 01 (January 2011): 66–74. http://dx.doi.org/10.1142/s1088424611002957.

Full text
Abstract:
Two cobalt porphyrins, (OEP) CoII and (TPP) CoII , where OEP and TPP are the dianions of octaethylporphyrin and tetraphenylporphyrin, respectively, were examined as electrocatalysts for the reductive dechlorination of DDT (1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane) in N,N′-dimethylformamide (DMF) containing 0.1 M tetra-n-butylammonium perchlorate (TBAP). No reaction is observed between DDT and the porphyrin in its Co(II) oxidation state but this is not the case for the reduced Co(I) forms of the porphyrins which electrocatalyze the dechlorination of DDT, giving initially DDD (1,1-bis(4-chlorophenyl)-2,2-dichloroethane), DDE (1,1-bis(4-chlorophenyl)-2, 2-dichloroethylene) and DDMU (1,1-bis(4-chlorophenyl)-2-chloroethylene) as determined by GC-MS analysis of the reaction products. A further dechlorination product, DDOH (2,2-bis(4-chlorophenyl)ethanol), is also formed on longer timescales when using (TPP)Co as the electroreduction catalyst. The effect of porphyrin structure and reaction time on the dechlorination products was examined by GC-MS, cyclic voltammetry, controlled potential electrolysis and UV-visible spectroelectrochemistry and a mechanism for the reductive dechlorination is proposed.
APA, Harvard, Vancouver, ISO, and other styles
25

Yuan, Bing, Riyue Ge, Shi-Zhao Kang, Lixia Qin, Guodong Li, and Xiangqing Li. "Self-directedly assembled porphyrin thin films with high photoactivity." RSC Advances 5, no. 114 (2015): 94046–52. http://dx.doi.org/10.1039/c5ra17015j.

Full text
APA, Harvard, Vancouver, ISO, and other styles
26

STEIGER, BEAT, and FRED C. ANSON. "Preparation, Isolation and Electrochemical Characterization of Cobalt Porphyrins with Ru(NH3)52+ Complexes Coordinated to 4-Cyanophenyl Substituents in the 5, 10, 15 and 20 Positions on the Porphyrin Ring." Journal of Porphyrins and Phthalocyanines 03, no. 02 (February 1999): 159–65. http://dx.doi.org/10.1002/(sici)1099-1409(199902)3:2<159::aid-jpp113>3.0.co;2-e.

Full text
Abstract:
A procedure has been devised by which quantitative coordination of Ru ( NH 3)52+ groups to the nitrile sites in [5,10,15,20-tetrakis(4-cyanophenyl)porphyrinato]cobalt(II) and [5,10,15,20-tetrakis(4-cyano-2,6-dimethylphenyl)porphyrinato]cobalt(II) can be achieved. The procedure takes advantage of the solubility of both [ Ru ( NH 3)5( OSO 2 CF 3)]( CF 3 SO 3)2 and either porphyrin in a mixed solvent consisting of 1,2-dimethoxyethane/N,N-dimethylacetamide (27:1 v/v). This new synthetic procedure allowed the fully ruthenated porphyrins to be isolated as solids in milligram quantities. The products were characterized using cyclic and rotating disk voltammetry and infrared and NMR spectroscopy.
APA, Harvard, Vancouver, ISO, and other styles
27

QIU, AIMIN, and DONALD T. SAWYER. "The Electrochemical Evaluation of the Metal-Carbon Bond Energies (−ΔGBF) of Alkylated Iron and Cobalt Porphyrins [(por)M-R]." Journal of Porphyrins and Phthalocyanines 01, no. 02 (April 1997): 125–34. http://dx.doi.org/10.1002/(sici)1099-1409(199704)1:2<125::aid-jpp15>3.0.co;2-x.

Full text
Abstract:
The electron-transfer oxidation-reduction chemistry for the alkyl derivatives of iron and cobalt porphyrins [( por ) M III − R ] has been characterized on the basis of cyclic voltammetric and controlled-potential-electrolysis measurements. The electrogenerated anions of iron and cobalt porphyrins [( por ) M − and ( por −·) M −] are strong nucleophiles that react with alkyl halides ( RX ) via a nucleophilic displacement process to form metal-carbon bonds [( por ) M - R and ( por −·) M - R ]. The difference in the reduction potentials for RX and ( por ) M II provides an approximate measure of the ( por ) M - R bond-formation free energy (−ΔG BF ). The −ΔG BF values for iron porphyrins (14–35 kcal mol−1) and for cobalt porphyrins (20-38 kcal mol−1) depend on the electron density of the porphyrin ring ( OEP > TPP > Cl 8 TPP > F 20TPP) and the structure of the alkyl group (1° > 2° > 3°). Thus, the apparent metal-carbon bond energy (−ΔG BF ) for ( OEP ) Fe III- Bu -n is 28 ± 2 kcal mol−1, and for [( MeO )4 TPP ] Co III- Bu -n is 36 ± 2 kcal mol −1. The ( por −·) M − dianions react with carbon dioxide in an electrocatalysed reduction cycle to give CO and CO 32− via the apparent transient formation of a metal-carbon bond [( por −·) M - C ( O ) O −; −Δ G BF ≥ 12 kcal mol −1 for iron porphyrins].
APA, Harvard, Vancouver, ISO, and other styles
28

Anca Lascu, Anca Lascu, Anca Palade Anca Palade, and Mihaela Birdeanu and Eugenia Fagadar Cosma Mihaela Birdeanu and Eugenia Fagadar Cosma. "Procaine Detection Using Hybrids of Cobalt-Metalloporphyrin with Gold and Silver Nanoparticles." Journal of the chemical society of pakistan 41, no. 1 (2019): 43. http://dx.doi.org/10.52568/000725/jcsp/41.01.2019.

Full text
Abstract:
Two organic-inorganic nanomaterials derived from Co(II)-tetra(3-hydroxyphenyl)porphyrin (Co-3OHPP) and noble metal nanoparticles, namely: Co-porphyrin-nanoAu (Co-3OHPP/nAu) and Co-porphyrin-nanoAg (Co-3OHPP/nAg) were obtained and tested for their capacity to detect procaine. Both hybrids present changes in UV-vis spectroscopy after interaction with procaine, in the same range of procaine concentration. The silver colloid is more easily obtainable and more economically affordable and its hybrid has a wider range of procaine detection from 5.39 x 10-5 mol l-1 to 28.04 x 10-5 mol l-1 concentration, thus being useful for the monitoring of the anesthesic remanence in patients’ plasma. Besides, the plasmonic band of the hybrid is more clearly defined. AFM studies were performed to compare the morphology of the two hybrid materials, Co-3OHPP/nAu and Co-3OHPP/nAg after being exposed to procaine. Both materials display triangular geometries that in case of Co-3OHPP/nAg are not very well defined taking also the form of kvatarons and these two coexisting forms generate pyramidal architectures.
APA, Harvard, Vancouver, ISO, and other styles
29

Ben Yahia, Manel, and Mohamed Ben Yahia. "New insights in the physicochemical investigation of the vitamin B12 nucleus using statistical physics treatment: interpretation of experiments and surface properties." RSC Advances 10, no. 37 (2020): 21724–35. http://dx.doi.org/10.1039/d0ra03077e.

Full text
APA, Harvard, Vancouver, ISO, and other styles
30

Zhao, Huanqin, Baolong Wang, Qingpan Li, Liying Wang, Junmin Sun, Yongfeng Zhang, Lichun Ji, and Zhenzhu Cao. "Dispersion and soap-free emulsion polymerization of tert-butyl acrylate with the living character and controlled particle size mediated by cobalt porphyrin." RSC Advances 7, no. 17 (2017): 10124–31. http://dx.doi.org/10.1039/c6ra28325j.

Full text
Abstract:
Living radical polymerization (LRP) of tert-butyl acrylate (tBA) was carried out via the dispersion and soap-free emulsion polymerization mediated by cobalt porphyrin [cobalt tetramethoxyphenylporphyrin, (TMOP)Co(ii)].
APA, Harvard, Vancouver, ISO, and other styles
31

Wang, Liying, Huanqin Zhao, Baolong Wang, Junmin Sun, Yongfeng Zhang, Lichun Ji, and Zhenzhu Cao. "Dispersion polymerization of acrylamide with living character and controlled morphologies initiated and mediated by cobalt porphyrin." RSC Advances 6, no. 68 (2016): 63519–24. http://dx.doi.org/10.1039/c6ra09619k.

Full text
Abstract:
Dispersion polymerization of acrylamide (AM) catalyzed by cobalt porphyrin [cobalt tetramethoxyphenylporphyrin, (TMOP)Co(ii)] with the feature of living radical polymerization (LRP) in alcohol/water or dimethylformamide (DMF)/water is described.
APA, Harvard, Vancouver, ISO, and other styles
32

Amiri, Nesrine, Mouhieddinne Guergueb, Maged S. Al-Fakeh, Marwa Bourguiba, and Habib Nasri. "A new cobalt(ii) meso-porphyrin: synthesis, characterization, electric properties and application in the catalytic degradation of dyes." RSC Advances 10, no. 73 (2020): 44920–32. http://dx.doi.org/10.1039/d0ra08786f.

Full text
Abstract:
In this work, a new porphyrin, 5,10,15,20-tetrakis{4-[((4-methoxyphenyl)acetyl)oxy]phenyl}porphyrin (H2TMAPP) (1), and its cobalt complex [CoII(TMAPP)] (2) were synthesized in good and quantitative yields, respectively.
APA, Harvard, Vancouver, ISO, and other styles
33

Hou, Zongsheng, Chongqing Yang, Wenbei Zhang, Chenbao Lu, Fan Zhang, and Xiaodong Zhuang. "Cobalt/nitrogen co-doped porous carbon nanosheets as highly efficient catalysts for the oxygen reduction reaction in both basic and acidic media." RSC Advances 6, no. 85 (2016): 82341–47. http://dx.doi.org/10.1039/c6ra16539g.

Full text
Abstract:
Cobalt/nitrogen co-doped porous carbon nanosheets as highly-efficient catalysts for ORR in both basic and acidic electrolytes have been prepared by using cobalt porphyrin based conjugated microporous polymer nanosheet as a precursor.
APA, Harvard, Vancouver, ISO, and other styles
34

Zhang, X., S. Zhu, J. Ruppel, H. Lu, and L. Wojtas. "Asymmetric Cyclopropanation with Cobalt-Porphyrin Complex." Synfacts 2008, no. 7 (July 2008): 0720. http://dx.doi.org/10.1055/s-2008-1077841.

Full text
APA, Harvard, Vancouver, ISO, and other styles
35

Hopmann, Kathrin H., and Abhik Ghosh. "Mechanism of Cobalt-Porphyrin–Catalyzed Aziridination." ACS Catalysis 1, no. 6 (April 29, 2011): 597–600. http://dx.doi.org/10.1021/cs1001114.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Han, Ali, Hongxing Jia, Hao Ma, Shifan Ye, Haotian Wu, Haitao Lei, Yongzhen Han, Rui Cao, and Pingwu Du. "Cobalt porphyrin electrode films for electrocatalytic water oxidation." Phys. Chem. Chem. Phys. 16, no. 23 (2014): 11224–32. http://dx.doi.org/10.1039/c4cp00523f.

Full text
Abstract:
Two water-insoluble cobalt porphyrin complexes were synthesized and used to prepare electrode films on FTO. The films showed good activities and possible recyclability for water oxidation catalysis under benign conditions. No heterogeneous cobalt oxides were observed in the reaction system, as have been confirmed by UV-vis spectroscopy, mass spectrometry, SEM, and EDX measurements.
APA, Harvard, Vancouver, ISO, and other styles
37

Lai, Ya-Yuan, Yu-Chang Chang, Jyh-Horung Chen, Shin-Shin Wang, and Jo-Yu Tung. "Axial zero-field splitting in mononuclear Co(ii) 2-N substituted N-confused porphyrin: Co(2-NC3H5-21-Y-CH2C6H4CH3-NCTPP)Cl (Y = o, m, p) and Co(2-NC3H5-21-CH2C6H5-NCTPP)Cl." Dalton Transactions 45, no. 11 (2016): 4854–62. http://dx.doi.org/10.1039/c6dt00137h.

Full text
Abstract:
Four inner C-benzyl and C-xylyl-substituted cobalt(ii) complexes of a 2-N-substituted N-confused porphyrin were synthesized and the D-parameter is related to the structural parameters of the cobalt(ii) complexes.
APA, Harvard, Vancouver, ISO, and other styles
38

Liu, Zishan, Liang Dong, Feifeng Li, Changjun Hou, Kun He, and Danqun Huo. "Determination of the binding mechanism of cobalt(II) meso-tetraphenyl porphyrin with plant-esterase." Polish Journal of Chemical Technology 23, no. 1 (March 1, 2021): 25–30. http://dx.doi.org/10.2478/pjct-2021-0004.

Full text
Abstract:
Abstract Plant-esterase (EC 3.1.1.X) has received much attention because plant esterase and acetylcholinesterase (AChE) share a similar sensitivity towards organophosphorus (OP) pesticides detection with the same inhibition mechanism. To improve the analytical performance, tetraphenyl metal porphyrin, as an indicator was introduced to combine with plant-esterase. The time of reach equilibrium in PBS solution was shortened after adding plant-esterase by assaying the intensify change of the porphyrin spectrum. Meanwhile, intensify of porphyrin spectrum with plant-esterase was increased compared with that of only the porphyrin spectrum in solution. Tetraphenyl metal porphyrin, such as cobalt(II) meso-tetraphenyl porphyrin, is a mixed reversible inhibitor of plant-esterase from kinetic parameters. The combination ratio of plant-esterase and porphyrin is 2:1. On the other hand, the interaction between CoTPPCl and plant-esterase is the strongest among all tested tetraphenyl metal porphyrin. And the mixed system (CoTPPCl-plant-esterase) showed the best sensitivity towards the tested pesticide. All these results indicated that a complex system composed of tetraphenyl metal porphyrin and plant-esterase was fit for detecting pesticides. They make meaningful guidance on the further design of sensing material in monitoring pesticides.
APA, Harvard, Vancouver, ISO, and other styles
39

Ghafuri, Hossein, Zahra Movahedinia, Rahmatollah Rahimi, and Hamid Reza Esmaili Zand. "Synthesis of 5,10,15,20-tetrakis[4-(naphthalen-2-yloxycarbonyl)phenyl]porphyrin (TNBP) and its complexes with zinc and cobalt and an investigation of the photocatalytic activity of nanoFe3O4@ZrO2–TNBP." RSC Advances 5, no. 74 (2015): 60172–78. http://dx.doi.org/10.1039/c5ra11126a.

Full text
Abstract:
5,10,15,20-Tetrakis[4-(naphthalen-2-yloxycarbonyl)phenyl]porphyrin and its porphyrin complexes with zinc and cobalt and nanoFe3O4@ZrO2–TNBP photocatalysts were synthesized with high yields and the structure and morphology were fully characterized.
APA, Harvard, Vancouver, ISO, and other styles
40

Sabater, Laurent, Pei-Ju Fang, Chi-Fon Chang, Aurore De Rache, Enora Prado, Jérôme Dejeu, Antonio Garofalo, et al. "Cobalt(iii)porphyrin to target G-quadruplex DNA." Dalton Transactions 44, no. 8 (2015): 3701–7. http://dx.doi.org/10.1039/c4dt03631j.

Full text
APA, Harvard, Vancouver, ISO, and other styles
41

Feldborg, Lise N., Wojciech J. Saletra, Patrizia Iavicoli, and David B. Amabilino. "Central metal ion determined self-assembly of intrinsically chiral porphyrins." Journal of Porphyrins and Phthalocyanines 15, no. 09n10 (September 2011): 995–1003. http://dx.doi.org/10.1142/s108842461100394x.

Full text
Abstract:
The aggregation of a tetraaryl-porphyrin with chiral amide-containing side groups depends critically on the central metal ion in the tetrapyrrolic core, an effect shown dramatically in solution as well as in the gel formation by the compounds. In solution, the circular dichroism (CD) spectra of the metalloporphyrins show that they all aggregate to some degree, and in most cases the aggregates of the metal-containing species is more favored than the parent free-base porphyrin. The compound which shows the greatest optical activity is the zinc(II) porphyrin which forms a J-aggregate with large Cotton effects in the CD spectrum. Infrared spectroscopy revealed that this aggregate is favored by interaction of the amide oxygen atom with the zinc(II) ion at the core of the porphyrin. The other metalloporphyrins, containing divalent copper, cobalt, and palladium or manganese(III) acetate all show CD activity, and all but the cobalt compound form gels in hexane or cyclohexane. The morphology of the xerogels formed after evaporation of the solvent from these gels depend greatly on the metal ion, with only the copper porphyrin — which shows a clear H-aggregate in solution — having a fibrous morphology
APA, Harvard, Vancouver, ISO, and other styles
42

Runge, Steffen, Mathias O. Senge, and Karin Ruhlandt-Senge. "5,10,15,20-Tetrakis(diphenylmethyl)porphyrin - A Nonplanar Porphyrin with Intermediate Degree of Ruffling." Zeitschrift für Naturforschung B 54, no. 5 (May 1, 1999): 662–66. http://dx.doi.org/10.1515/znb-1999-0515.

Full text
Abstract:
The title compound was prepared by condensation of pyrrole and diphenylacetaldehyde in 16% yield. Based on spectroscopic data, the free base porphyrin exhibits a nonplanar macrocycle in solution with a degree of distortion between that of 5,10,15,20-tetracyclohexylporphyrin and 5,10,15,20-tetra(t-butyl)porphyrin. A crystal structure determination of the cobalt(II) complex reveals a ruffled macrocycle conformation with an average out-of-plane displacement of the meso carbon atoms by 0.55 Å.
APA, Harvard, Vancouver, ISO, and other styles
43

Chen, Sudi, Xitong Ren, Shufang Tian, Jiajie Sun, and Feng Bai. "Controllable Synthesis of Cobalt Porphyrin Nanocrystals through Micelle Confinement Self-Assembly." MRS Advances 5, no. 42 (2020): 2147–55. http://dx.doi.org/10.1557/adv.2020.269.

Full text
Abstract:
AbstractThe self-assembly of optically active building blocks into functional nanocrystals as high-activity photocatalysts is a key in the field of photocatalysis. Cobalt porphyrin with abundant catalytic properties is extensively studied in photocatalytic water oxidation and CO2 reduction. Here, we present the fabrication of cobalt porphyrin nanocrystals through a surfactant-assisted interfacial self-assembly process using Co-tetra(4-pyridyl) porphyrin as building block. The self-assembly process relies on the combined noncovalent interactions such as π-π stacking and axial Co-N coordination between individual porphyrin molecules within surfactant micelles. Tuning different reaction conditions (temperature, the ratio of co-solvent DMF) and types of surfactant, various nanocrystals with well-defined 1D to 3D morphologies such as nanowires, nanorods and nano hexagonal prism were obtained. Due to the ordered accumulation of molecules, the nanocrystals exhibit the properties of the enhanced capability of visible light capture and can conduce to improve the transport and separation efficiency of the photogenerated carriers, which is important for photocatalysis. Further studies of photocatalytic CO2 reduction are being performed to address the relationship between the size and shape of the nanocrystals with the photocatalytic activity.
APA, Harvard, Vancouver, ISO, and other styles
44

Iwanaga, Osamu, Mayuko Miyanishi, Toshihiro Tachibana, Takaaki Miyazaki, Yoshihito Shiota, Kazunari Yoshizawa, and Hiroyuki Furuta. "A Computational Study on the Mechanism of Catalytic Cyclopropanation Reaction with Cobalt N-Confused Porphyrin: The Effects of Inner Carbon and Intramolecular Axial Ligand." Molecules 27, no. 21 (October 26, 2022): 7266. http://dx.doi.org/10.3390/molecules27217266.

Full text
Abstract:
The factors that affect acceleration and high trans/cis selectivity in the catalytic cyclopropanation reaction of styrene with ethyl diazoacetate by cobalt N-confused porphyrin (NCP) complexes were investigated using density functional theory calculations. The reaction rate was primarily related to the energy gap between the cobalt–carbene adduct intermediates, A and B, which was affected by the NCP skeletons and axial pyridine ligands more than the corresponding porphyrin complex. In addition, high trans/cis stereoselectivity was determined at the TS1 and, in part, in the isomerization process at the carbon-centered radical intermediates, Ctrans and Ccis.
APA, Harvard, Vancouver, ISO, and other styles
45

Bichan, N. G., E. N. Ovchenkova, N. O. Kudryakova, A. A. Ksenofontov, M. S. Gruzdev, and T. N. Lomova. "Self-assembled cobalt(ii)porphyrin–fulleropyrrolidine triads via axial coordination with photoinduced electron transfer." New Journal of Chemistry 42, no. 15 (2018): 12449–56. http://dx.doi.org/10.1039/c8nj00887f.

Full text
APA, Harvard, Vancouver, ISO, and other styles
46

Nakazono, Takashi, and Ken Sakai. "Improving the robustness of cobalt porphyrin water oxidation catalysts by chlorination of aryl groups." Dalton Transactions 45, no. 32 (2016): 12649–52. http://dx.doi.org/10.1039/c6dt02535h.

Full text
APA, Harvard, Vancouver, ISO, and other styles
47

Pamin, Katarzyna, Jan Połtowicz, Joanna Kiełkowicz, and Andrzej Hendrich. "Interaction of metalloporphyrins with lipid bilayers, a calorimetric study." Current Topics in Biophysics 34, no. 1 (January 1, 2011): 11–14. http://dx.doi.org/10.2478/v10214-011-0002-5.

Full text
Abstract:
Interaction of metalloporphyrins with lipid bilayers, a calorimetric studyThe interaction of three metalloporphyrins, containing manganese, iron and cobalt atoms, with lipid bilayers composed of neutral (DPPC) or charged (DMPG) phospholipids were studied by means of scanning differential calorimetry. We found only minute effects exerted by studied compounds on DPPC, while phase transitions of charged DMPG were seriously affected by porphyrins. Analysis of experimental data revealed that due to the electrostatic interactions DMPG bilayers are perturbed not only in the polar head group region. Putative rearrangements of the polar heads packing affects also the acyl chain region of this lipid bilayer. Perturbation of DMPG polar heads induced by porphyrin in complex with manganese atoms is bigger than that induced by other porphyrins.
APA, Harvard, Vancouver, ISO, and other styles
48

Gridnev, Alexei A., Steven D. Ittel, Michael Fryd, and Bradford B. Wayland. "Formation of organocobalt porphyrin complexes from reactions of cobalt(II) porphyrins and dialkylcyanomethyl radicals with organic substrates: chemical trapping of a transient cobalt porphyrin hydride." Organometallics 12, no. 12 (December 1993): 4871–80. http://dx.doi.org/10.1021/om00036a029.

Full text
APA, Harvard, Vancouver, ISO, and other styles
49

Kaur, Balwinder, Kamila Malecka, Domenico A. Cristaldi, Clarissa S. Chay, Iwona Mames, Hanna Radecka, Jerzy Radecki, and Eugen Stulz. "Approaching single DNA molecule detection with an ultrasensitive electrochemical genosensor based on gold nanoparticles and cobalt-porphyrin DNA conjugates." Chemical Communications 54, no. 79 (2018): 11108–11. http://dx.doi.org/10.1039/c8cc05362f.

Full text
APA, Harvard, Vancouver, ISO, and other styles
50

Goodwin, John A., and Tigran S. Kurtikyan. "Electrocatalytic reactions of dioxygen and nitric oxide with reduced (nitrosyl) cobalt porphyrins — cyclic voltammetry and computational chemistry." Journal of Porphyrins and Phthalocyanines 15, no. 02 (February 2011): 99–105. http://dx.doi.org/10.1142/s1088424611003033.

Full text
Abstract:
Water-soluble cationic cobalt(tetra(N-methyl-pyridyl)porphyrins, CoTMpyP(4) and CoTMpyP(2) and the β-pyrrole octabrominated derivative CoTMpyP(4)Br8 have been studied by cyclic voltammetry under aqueous aerobic conditions at pH of 4.0 with and without addition of nitrite to explore their ability to catalyze the reduction of dioxygen. The porphyrins and their nitro/nitrosyl derivatives were studied in aqueous acetate buffer solution at a solid silver electrode and then also as they were immobilized in Nafion® film loaded with silver nanoparticles which provided electrical conductivity. Under these reducing conditions with nitrite in solution, coordinated nitrite appears to undergo an oxo-transfer/reduction reaction resulting in the formation of the nitrosyl ligand. The reaction of the nitrosyl complex allows a short-lived electrocatalytic reduction reaction with dioxygen before NO is lost from the complex by dissociation. The thermodynamics of the reactions and possible catalytic intermediates in the reduction of dioxygen were studied by DFT (BP/6-31G*) computations. An unusual N -bound cyclic NO3- structure was obtained in the optimized geometries for the product of reduced nitrosyl porphyrins and dioxygen in the model complexes and for [CoTMpyP(2)(NO-O2)]- . These structures are tentatively proposed to represent an intermediate in the mechanism of activation of dioxygen in catalytic reduction. DFT (BP/6-31G*) computations were also applied to probe thermodynamics and intermediates in the known catalytic reduction of NO to N2O by the reduced porphyrin under anaerobic conditions. Thermodynamics estimates suggest that reduction occurs through coordinated NO in the reduced porphyrin species similar to cytochrome P450nor (nitric oxide reductase), but the detailed mechanism is not clear.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Cobalt porphyrin' for other source types:
Dissertations / Theses
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography