Oxidation states of manganese porphyrins in water solutions

2005 ◽  
Vol 09 (06) ◽  
pp. 436-443 ◽  
Author(s):  
Oscar Ramirez-Gutierrez ◽  
Josep Claret ◽  
Josep M. Ribo
Keyword(s):  
Oxidation State ◽  
Water Soluble ◽  
Oxidation States ◽  
Vitreous Carbon ◽  
Alkaline Solutions ◽  
Carbon Electrode ◽  
Water Solutions ◽  
Manganese Porphyrins ◽  
Electron Reduction ◽  
Mn Porphyrins

The Mn oxidation state of two water soluble Mn porphyrins, MnTMPyP and MnTPPS 4, was studied as a function of the aqua or hydroxo ligands of the Mn atom. In NaOH solutions, long-lived O = Mn(IV) species were detected in the presence of O 2. Conversely, the dihydroxo Mn(III) porphyrin reduces spontaneously to the Mn(II) species in the absence of O 2. In alkaline solutions, these Mn porphyrins were able to electrocatalyze the 4-electron reduction of O 2 to H 2 O on a vitreous carbon electrode.

Cyclic voltammetry of water-soluble manganese porphyrins in the presence of cyclodextrins

2005 ◽  
Vol 09 (05) ◽  
pp. 368-376 ◽  
Author(s):  
Oscar Ramirez-Gutierrez ◽  
Josep Claret ◽  
Josep M. Ribo
Keyword(s):  
Cyclic Voltammetry ◽  
Aqueous Solutions ◽  
Inclusion Complexes ◽  
Electrode Surface ◽  
Water Soluble ◽  
Manganese Porphyrins ◽  
Mn Porphyrins

The addition of cyclodextrins (α-CD, β-CD, 2-hydroxopropyl-β-CD and γ-CD) to aqueous solutions of representative cationic ( MnTMPyP ) and anionic ( MnTPPS 4) water-soluble Mn porphyrins only substantially affect the behavior of the Mn (III)/ Mn (II) couple when inclusion complexes (i.e. for MnTPPS 4) are formed. The voltammetric responses were interpreted under the assumption that the inclusion complexes are electroactive, which occurs after their adsorption on the electrode surface. In addition, the results point to a higher affinity of the cyclodextrins for Mn II TPPS 4 than for Mn III TPPS 4.

Heterogeneous metal-insertion: a novel reaction with porphyrins

1978 ◽  
Vol 56 (8) ◽  
pp. 1084-1087 ◽  
Author(s):  
Otto Herrmann ◽  
S. Husain Mehdi ◽  
Alfio Corsini
Keyword(s):  
Metal Complexes ◽  
Oxidation State ◽  
High Purity ◽  
Heterogeneous Reaction ◽  
Water Soluble ◽  
Oxidation States ◽  
Insoluble Form ◽  
Metal Insertion ◽  
Lower Oxidation

Metal complexes of water-soluble and other porphyrins have been prepared by a heterogeneous reaction with the metal reactant present in an insoluble form. The oxidation state of the metal is important in the reactions. Metal reactants in the lower oxidation states (0, I, II) react with porphyrins but those in the higher oxidation states (III, IV) do not. Metalloporphyrins of high purity may be conveniently prepared by this method.

Sorption of Water Soluble Organic Dyes on Magnetic Poly(oxy-2,6-dimethyl-1,4-phenylene)

1995 ◽  
Vol 60 (9) ◽  
pp. 1448-1456 ◽  
Author(s):  
Ivo Šafařík ◽  
Miroslava Šafaříková ◽  
Vlasta Buřičová
Keyword(s):  
Organic Compounds ◽  
Azo Dye ◽  
Organic Dyes ◽  
Water Soluble ◽  
Magnetic Composite ◽  
Water Solutions ◽  
Magnetite Particles

Magnetic composite based on poly(oxy-2,6-dimethyl-1,4-phenylene) (PODMP) was prepared by melting the polymer with ε-caprolactam in a presence of fine magnetite particles. Magnetic PODMP was used for sorption of water soluble organic compounds (dyes belonging to triphenylmethane, heteropolycyclic and azo dye groups) from water solutions. There were considerable differences in the binding of the dyes tested. In general, heteropolycyclic dyes exhibited the lowest sorption.

Decoloration of Azo Dyes by Hydrogen Peroxide Catalyzed by Water-Soluble Manganese Porphyrins

1999 ◽  
Vol 69 (12) ◽  
pp. 956-960 ◽  
Author(s):  
J. Tokuda ◽  
R. Ohura ◽  
T. Iwasaki ◽  
Y. Takeuchi ◽  
A. Kashiwada ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Azo Dyes ◽  
Water Soluble ◽  
Manganese Porphyrins

scholarly journals Characterizing Wool Keratin

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jeanette M. Cardamone ◽  
Alberto Nuñez ◽  
Rafael A. Garcia ◽  
Mila Aldema-Ramos
Keyword(s):  
Hydrogen Peroxide ◽  
Gel Electrophoresis ◽  
Water Soluble ◽  
Alkaline Solutions ◽  
Biodegradable Material ◽  
Alkaline Hydrogen Peroxide ◽  
Cortical Cells ◽  
Sds Page ◽  
Fibrous Matrices ◽  
Wool Keratin

Keratin from wool is a reactive, biocompatible, and biodegradable material. As the biological structural component of skin (soft keratins) and of nails, claws, hair, horn, feathers, and scales (hard keratins) pure keratin comprises up to 90% by weight of wool. Wool was treated in alkaline solutions to extract from 68% to 82% keratin within 2 to 5 hours of exposure at . The keratin products were water-soluble and were confirmed to contain intermediate filament and microfibrillar component-proteins of fractured, residual cuticle, and cortical cells. Oxidation of wool by peroxycarboximidic acid in alkaline hydrogen peroxide produced keratin products with distinct microcrystalline structures: descaled fibers, fibrous matrices, and lyophilized powders. Morphology and confirmation of peptide functionality were documented by SEM, Amino Acid Analysis, SDS-PAGE gel electrophoresis, MALDI-TOF/TOF, and FTIR analyses. The reactivity of keratin from wool models the reactivity of keratin from low-value sources such as cattle hair.

scholarly journals Anion influence in lead removal from aqueous solution by deposition onto a vitreous carbon electrode

1999 ◽  
Vol 44 (15) ◽  
pp. 2633-2643 ◽  
Author(s):  
G. Carreño ◽  
E. Sosa ◽  
I. González ◽  
C. Ponce-de-León ◽  
N. Batina ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Vitreous Carbon ◽  
Lead Removal ◽  
Carbon Electrode

Stable copernicium hexafluoride (CnF6) with an oxidation state of +VI

2021 ◽  
Author(s):  
Shuxian Hu ◽  
Wenli Zou
Keyword(s):  
Oxidation State ◽  
Oxidation States ◽  
Group 12

As the heaviest group 12 element known now, copernicium (Cn) often presents the oxidation states of +I, +II, and rarely +IV as in its homologue mercury. In this work we...

scholarly journals Selenium– and tellurium–halogen reagents

2018 ◽  
Vol 3 (12) ◽  
Author(s):  
Tristram Chivers ◽  
Risto S. Laitinen
Keyword(s):  
Oxidation State ◽  
Halogen Bond ◽  
The Other ◽  
Oxidation States ◽  
Alkyl Aryl ◽  
Organic Selenium ◽  
Formal Oxidation State ◽  
Wide Range ◽  
Inorganic And Organic

Abstract Selenium and tellurium form binary halides in which the chalcogen can be in formal oxidation states (IV), (II) or (I). They are versatile reagents for the preparation of a wide range of inorganic and organic selenium and tellurium compounds taking advantage of the reactivity of the chalcogen–halogen bond. With the exception of the tetrafluorides, the tetrahalides are either commercially available or readily prepared. On the other hand, the low-valent species, EX2 (E = Se, Te; X = Cl, Br) and E2X2 (E = Se, Te; X = Cl, Br) are unstable with respect to disproportionation and must be used as in situ reagents. Organoselenium and tellurium halides are well-known in oxidation states (IV) and (II), as exemplified by REX3, R2EX2 and REX (R = alkyl, aryl; E = Se, Te; X = F, Cl, Br, I); mixed-valent (IV/II) compounds of the type RTeX2TeR are also known. This chapter surveys the availability and/or preparative methods for these widely used reagents followed by examples of their applications in synthetic inorganic and organic selenium and tellurium chemistry. For both the binary halides and their organic derivatives, the discussion is subdivided according to the formal oxidation state of the chalcogen.

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