scholarly journals Spectroscopic Characterization of Poly(ortho-Aminophenol) Film Electrodes: A Review Article

2013 ◽  
Vol 2013 ◽  
pp. 1-26 ◽  
Author(s):  
Ricardo Tucceri ◽  
Pablo Maximiliano Arnal ◽  
Alberto Néstor Scian
Keyword(s):  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Review Article ◽  
Electro Oxidation ◽  
Redox Conversion

This paper refers to spectroscopic studies carried out to identify the products ofo-aminophenol electro-oxidation and elucidate the structure of electrochemically synthesized poly(o-aminophenol) (POAP) films. Spectroscopic studies of the redox conversion of POAP are also reviewed.

Poly(o-aminophenol) film electrodes: synthesis and characterization and formation mechanisms — A review article

2013 ◽  
Vol 91 (2) ◽  
pp. 91-112 ◽  
Author(s):  
R. Tucceri ◽  
P.M. Arnal ◽  
A.N. Scian
Keyword(s):  
Chemical Structure ◽  
Electrode Materials ◽  
Film Formation ◽  
Protective Layer ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Formation Mechanisms ◽  
Neutral Media ◽  
Electro Oxidation ◽  
Basic Solutions

This review, which is divided into three parts, concerns electrochemical synthesis, spectroscopic characterization, and formation mechanisms of poly(o-aminophenol) (POAP) film electrodes. The first part of this review is devoted to describing the electropolymerization process of o-aminophenol (o-AP) on different electrode materials and in different electrolyte media by employing both potentiodynamic and potentiostatic methods. The evolution of the voltammogram during the electrosynthesis of POAP and the assignation of the voltammetric peaks to different species, according to the formation mechanism formulated by each author, are described. The effects of some chemical substances and electrochemical pretreatments of the electrode surface, on the electropolymerization process of o-AP, are also considered in this part of the review. The synthesis of POAP in neutral media, which yields a nonconducting polymer, and its use as component of biosensors and protective layer in corrosion processes, are analyzed at the end of the first part. The second part of this review refers to spectroscopic studies carried out by different authors to both identify the products of the o-AP electro-oxidation and elucidate the chemical structure of POAP film electrodes. This second part of the review also describes the different spectroscopic methods employed to study the redox process of POAP, which allows the demonstration of the existence of transient species during the transition of the completely oxidized form of POAP to the completely reduced one. The third part of this review shows the different mechanisms formulated to interpret the POAP film formation from both acid and basic solutions of o-AP. Also, some electrochemical and spectroscopic data which allowed to propos the corresponding formation mechanisms, especially in basic media, are described.

scholarly journals Functional, structural, and spectroscopic characterization of a glutathione-ligated [2Fe–2S] cluster in poplar glutaredoxin C1

2007 ◽  
Vol 104 (18) ◽  
pp. 7379-7384 ◽  
Author(s):  
Nicolas Rouhier ◽  
Hideaki Unno ◽  
Sibali Bandyopadhyay ◽  
Lluis Masip ◽  
Sung-Kun Kim ◽  
...  
Keyword(s):  
Intracellular Localization ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Iron Sulfur Cluster ◽  
X Ray Crystallography ◽  
Iron Sulfur ◽  
Catalytic Cysteine ◽  
A Subunit ◽  
Stress Sensing

When expressed in Escherichia coli, cytosolic poplar glutaredoxin C1 (CGYC active site) exists as a dimeric iron–sulfur-containing holoprotein or as a monomeric apoprotein in solution. Analytical and spectroscopic studies of wild-type protein and site-directed variants and structural characterization of the holoprotein by using x-ray crystallography indicate that the holoprotein contains a subunit-bridging [2Fe–2S] cluster that is ligated by the catalytic cysteines of two glutaredoxins and the cysteines of two glutathiones. Mutagenesis data on a variety of poplar glutaredoxins suggest that the incorporation of an iron–sulfur cluster could be a general feature of plant glutaredoxins possessing a glycine adjacent to the catalytic cysteine. In light of these results, the possible involvement of plant glutaredoxins in oxidative stress sensing or iron–sulfur biosynthesis is discussed with respect to their intracellular localization.

scholarly journals The Electrophoretic and Spectroscopic Characterization of Hgb M

Blood ◽  
1958 ◽  
Vol 13 (10) ◽  
pp. 936-949 ◽  
Author(s):  
PARK S. GERALD
Keyword(s):  
Relative Concentration ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Spectral Curves ◽  
Spectral Changes ◽  
Electrophoretic Behavior ◽  
Patient Reported ◽  
High Concentrations

Abstract The hemoglobin (hgb) from a patient with Hgb M disease was resolved into two components by starch block electrophoresis (at pH 7.0-7.2) of the oxidized hemolyzate. One component was identified electrophoretically and spectroscopically as Hgb A, and the other as Hgb M. Methods for the determination of the relative concentration of Hgb M were given. In the patient reported, Hgb M was found to comprise approximately 30 per cent of the total hgb. Spectroscopic studies of electrophoreticably isolated Hgb M demonstrated that both the methgb and the cyanmethgb form were abnormal in their spectral curves. The reactions of the methgb form with low and high concentrations of cyanide were found to differ. The nature of the spectral changes were such as to indicate that some of the heme groups of the methgb form react abnormally and others apparently normally. The electrophoretic behavior of the patient’s hemolyzate after treatment with various combinations of cyanide and ferricyanide was consistent with this hypothesis. The differing reactivity of the heme groups was explained in the light of the biochemical genetics of the abnormal hemoglobins.

scholarly journals Cu+-specific CopB transporter: Revising P1B-type ATPase classification

2018 ◽  
Vol 115 (9) ◽  
pp. 2108-2113 ◽  
Author(s):  
Rahul Purohit ◽  
Matthew O. Ross ◽  
Sharon Batelu ◽  
April Kusowski ◽  
Timothy L. Stemmler ◽  
...  
Keyword(s):  
Maximal Activity ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Divalent Metal Ions ◽  
X Ray ◽  
Reducing Environment ◽  
Methionine Residues ◽  
Cellular Copper ◽  
X Ray Absorption

The copper-transporting P1B-ATPases, which play a key role in cellular copper homeostasis, have been divided traditionally into two subfamilies, the P1B-1-ATPases or CopAs and the P1B-3-ATPases or CopBs. CopAs selectively export Cu+ whereas previous studies and bioinformatic analyses have suggested that CopBs are specific for Cu2+ export. Biochemical and spectroscopic characterization of Sphaerobacter thermophilus CopB (StCopB) show that, while it does bind Cu2+, the binding site is not the prototypical P1B-ATPase transmembrane site and does not involve sulfur coordination as proposed previously. Most important, StCopB exhibits metal-stimulated ATPase activity in response to Cu+, but not Cu2+, indicating that it is actually a Cu+ transporter. X-ray absorption spectroscopic studies indicate that Cu+ is coordinated by four sulfur ligands, likely derived from conserved cysteine and methionine residues. The histidine-rich N-terminal region of StCopB is required for maximal activity, but is inhibitory in the presence of divalent metal ions. Finally, reconsideration of the P1B-ATPase classification scheme suggests that the P1B-1- and P1B-3-ATPase subfamilies both comprise Cu+ transporters. These results are completely consistent with the known presence of only Cu+ within the reducing environment of the cytoplasm, which should eliminate the need for a Cu2+ P1B-ATPase.

scholarly journals Synthesis and Spectroscopic Characterization of Lead(II)bis{O,O'-ditolyldithiophosphates} and their Adducts with 2,2'-Bipyridyl and 1,10-Phenanthroline

2011 ◽  
Vol 8 (s1) ◽  
pp. S113-S118
Author(s):  
Disha Jain Alok Chaturvedi ◽  
R.K. Upadhayay
Keyword(s):  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Ammonium Salts ◽  
Molar Ratio ◽  
Spectroscopic Techniques ◽  
Lead Atom ◽  
H Nmr

The reaction of lead(II) dichloride with ammonium salts ofO,O'-ditolyldithiophosphoric acid have been carried out in 1:2 molar ratio by refluxing in benzene. These compounds have been further used to synthesize the adduct of the type lead(II)bis{O,O'-ditolyldithiophosphates}.2,2'-bipyridyl and lead(II)bis {O,O'-ditolyldithiophosphates}.1,10-phenanthroline by the reaction of lead(II)bis{O,O'-ditolyldithiophosphates} and 2,2'-bipyridyl and 1,10-phenanthro-line in the presence of unimolar dichloromethane and ethanol. All these complexes have been characterized by spectroscopic techniques such as IR,1H NMR and31P NMR. On the basis of spectroscopic studies tetracoordinated nature of lead atom in ditolyldithiophosphates complexes and hexacoordinated nature in their adducts have been established.

scholarly journals Electrosynthesis and Spectroscopic Characterization of Poly(o-Aminophenol) Film Electrodes

2012 ◽  
Vol 2012 ◽  
pp. 1-26 ◽  
Author(s):  
Ricardo Tucceri ◽  
Pablo Arnal ◽  
Alberto Scian
Keyword(s):  
Electrochemical Synthesis ◽  
Spectroscopic Data ◽  
Chemical Structure ◽  
Electrode Materials ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Formation Mechanisms ◽  
The Third ◽  
Basic Solutions

This review, which is divided into three parts, concerns electrochemical synthesis, spectroscopic characterization, and formation mechanisms of poly(o-aminophenol) (POAP) film electrodes. The first part of this review is devoted to describe the electropolymerization process of o-aminophenol on different electrode materials and in different electrolyte media by employing both potentiodynamic and potentiostatic methods. The second part refers to spectroscopic studies carried out by different authors to both, identify the products of the o-aminophenol electrooxidation and elucidate the chemical structure of poly(o-aminophenol) film electrodes. The third part shows the different mechanisms formulated to interpret the POAP films formation from both acid and basic solutions of o-AP. Also, some electrochemical and spectroscopic data which allowed to propos the corresponding formation mechanisms, especially in basic media, are described.

scholarly journals Synthesis and Spectroscopic Characterization of Thienopyrazine-Based Fluorophores for Application in Luminescent Solar Concentrators (LSCs)

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5428
Author(s):  
Xheila Yzeiri ◽  
Massimo Calamante ◽  
Alessio Dessì ◽  
Daniele Franchi ◽  
Andrea Pucci ◽  
...  
Keyword(s):  
Stokes Shift ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Solar Concentrators ◽  
Luminescent Solar Concentrators ◽  
Silicon Photovoltaics ◽  
Donor Acceptor ◽  
Intense Light ◽  
Stokes Shifts

Organic fluorophores have found broad application as emitters in luminescent solar concentrators (LSCs) for silicon photovoltaics. In particular, the preparation of organic conjugated systems with intense light-harvesting ability, emissions in the deep-red and NIR regions, and large Stokes shift values represent a very challenging undertaking. Here, we report a simple and easy way to prepare three symmetrical donor–acceptor–donor (DAD) organic-emitting materials based on a thienopyrazine core. The central core in the three dyes was modified with the introduction of aromatic substituents, aiming to affect their optical properties. The fluorophores were characterized by spectroscopic studies. In all cases, visible-NIR emissions with large Stokes shifts were found, highlighting these molecules as promising materials for the application in LSCs.

scholarly journals A functional description of CymA, an electron-transfer hub supporting anaerobic respiratory flexibility in Shewanella

2012 ◽  
Vol 444 (3) ◽  
pp. 465-474 ◽  
Author(s):  
Sophie J. Marritt ◽  
Thomas G. Lowe ◽  
Jordan Bye ◽  
Duncan G. G. McMillan ◽  
Liang Shi ◽  
...  
Keyword(s):  
High Spin ◽  
Shewanella Oneidensis ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Redox Partner ◽  
Quinol Oxidation ◽  
Thermodynamic Driving Force ◽  
Redox Poise ◽  
Quinol Binding

CymA (tetrahaem cytochrome c) is a member of the NapC/NirT family of quinol dehydrogenases. Essential for the anaerobic respiratory flexibility of shewanellae, CymA transfers electrons from menaquinol to various dedicated systems for the reduction of terminal electron acceptors including fumarate and insoluble minerals of Fe(III). Spectroscopic characterization of CymA from Shewanella oneidensis strain MR-1 identifies three low-spin His/His co-ordinated c-haems and a single high-spin c-haem with His/H2O co-ordination lying adjacent to the quinol-binding site. At pH 7, binding of the menaquinol analogue, 2-heptyl-4-hydroxyquinoline-N-oxide, does not alter the mid-point potentials of the high-spin (approximately −240 mV) and low-spin (approximately −110, −190 and −265 mV) haems that appear biased to transfer electrons from the high- to low-spin centres following quinol oxidation. CymA is reduced with menadiol (Em=−80 mV) in the presence of NADH (Em=−320 mV) and an NADH–menadione (2-methyl-1,4-naphthoquinone) oxidoreductase, but not by menadiol alone. In cytoplasmic membranes reduction of CymA may then require the thermodynamic driving force from NADH, formate or H2 oxidation as the redox poise of the menaquinol pool in isolation is insufficient. Spectroscopic studies suggest that CymA requires a non-haem co-factor for quinol oxidation and that the reduced enzyme forms a 1:1 complex with its redox partner Fcc3 (flavocytochrome c3 fumarate reductase). The implications for CymA supporting the respiratory flexibility of shewanellae are discussed.

Spectroscopic studies of peroxo/hydroperoxo derivatives of heme proteins and model compounds

2004 ◽  
Vol 08 (03) ◽  
pp. 215-225 ◽  
Author(s):  
Mohammed Ibrahim ◽  
James R. Kincaid
Keyword(s):  
Heme Proteins ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Model Compounds ◽  
Paramagnetic Resonance ◽  
Biochemical Systems ◽  
And Function ◽  
Electron Paramagnetic ◽  
Derivatives Of

The spectroscopic characterization of peroxo- and hydroperoxo- intermediates of heme proteins and enzymes has long interested scientists studying the structure and function of these important biochemical systems. Until very recently, little progress had been made in studying these fleeting intermediates by vibrational spectroscopic methods. In this brief review, recent studies reporting the Resonance Raman and Infrared spectra of such intermediates and pertinent model compounds are reviewed and compared to corresponding studies utilizing electronic absorption and electron paramagnetic resonance spectrometric methods.

scholarly journals SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OF SOME NEW HYDROGENOXALATO ORGANOTIN (IV) COMPLEXES

2020 ◽  
Vol 26 (2) ◽  
pp. 15-19
Author(s):  
MOUHAMADOU SEMBENE BOYE ◽  
AMINATA DIASSE-SARR ◽  
LIBASSE DIOP
Keyword(s):  
Hydrogen Bonds ◽  
Spectroscopic Data ◽  
Spectroscopic Characterization ◽  
Spectroscopic Studies ◽  
Supramolecular Architectures ◽  
Polymeric Structures

The synthesis and spectroscopic studies (infrared and Mössbauer) of new hydrogenoxalato derivatives and adducts containing SnRn (R=Me, Ph; n=2, 3) residues are reported. Based on their spectroscopic data dimeric and polymeric structures containing hexacoordinated or pentacoordinated Sn are suggested, the hydrogenoxolate anion behaving as a monocoordinating or a monochelating ligand. In two studied adducts, supramolecular architectures may be obtained when extra hydrogen bonds involving the free NH groups are considered.

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