major oxidation
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Author(s):  
Dr. Nasser K Thallaj ◽  

This report describes how the coordination of FeCl2 with tris(pyridin-2-ylmethyl)amine (TPA) ligands offers the possibilty to activate the molecular dioxygen in biomimetic processes. . It includes all procedures taken to the case for major oxidation reactions carried out in Nature under particular conditions. The aim of the this paper is to present the outcome of a thorough study for complex coordinations with ligands substituted by groups known as electron donors. It demonstrates how ligands with methoxy substituents are likely to be demethylated, and therefore providing entities potentially useful in synthesis. Targeting in modulating the electronic properties at the metal center, a new type of ligand (MeO)2TPA has been prepared and the complex of (MeO)2TPAFeCl2 has been studied by uv-visble ; 1H RMN paramagnatic and conductometry. The effect of (MeO) group in α-substituted on the structure as well as the effect of substitution on the oxygenation of the complex has been verified. Afterwards, the reactivity of the complex towards molecular dioxygen in absence of substrat is checked by uv-visble, 1H RMN paramagnatic and radiocristallography. As well, the reactivity in presence of substrat is tested.


2021 ◽  
Vol 1 (2) ◽  
pp. 1-2
Author(s):  
Dr. Nasser K Thallaj* ◽  

This report describes how the coordination of FeCl2 with tris(pyridin-2-ylmethyl)amine (TPA) ligands offers the possibilty to activate the molecular dioxygen in biomimetic processes. . It includes all procedures taken to the case for major oxidation reactions carried out in Nature under particular conditions. The aim of the this paper is to present the outcome of a thorough study for complex coordinations with ligands substituted by groups known as electron donors. It demonstrates how ligands with methoxy substituents are likely to be demethylated, and therefore providing entities potentially useful in synthesis. Targeting in modulating the electronic properties at the metal center, a new type of ligand (MeO)2TPA has been prepared and the complex of (MeO)2TPAFeCl2 has been studied by uv-visble ; 1H RMN paramagnatic and conductometry. The effect of (MeO) group in α-substituted on the structure as well as the effect of substitution on the oxygenation of the complex has been verified. Afterwards, the reactivity of the complex towards molecular dioxygen in absence of substrat is checked by uvvisble, 1H RMN paramagnatic and radiocristallography. As well, the reactivity in presence of substrat is tested.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andrew R. J. Murphy ◽  
David J. Scanlan ◽  
Yin Chen ◽  
Nathan B. P. Adams ◽  
William A. Cadman ◽  
...  

AbstractThe planktonic synthesis of reduced organophosphorus molecules, such as alkylphosphonates and aminophosphonates, represents one half of a vast global oceanic phosphorus redox cycle. Whilst alkylphosphonates tend to accumulate in recalcitrant dissolved organic matter, aminophosphonates do not. Here, we identify three bacterial 2-aminoethylphosphonate (2AEP) transporters, named AepXVW, AepP and AepSTU, whose synthesis is independent of phosphate concentrations (phosphate-insensitive). AepXVW is found in diverse marine heterotrophs and is ubiquitously distributed in mesopelagic and epipelagic waters. Unlike the archetypal phosphonate binding protein, PhnD, AepX has high affinity and high specificity for 2AEP (Stappia stellulata AepX Kd 23 ± 4 nM; methylphosphonate Kd 3.4 ± 0.3 mM). In the global ocean, aepX is heavily transcribed (~100-fold>phnD) independently of phosphate and nitrogen concentrations. Collectively, our data identifies a mechanism responsible for a major oxidation process in the marine phosphorus redox cycle and suggests 2AEP may be an important source of regenerated phosphate and ammonium, which are required for oceanic primary production.


2021 ◽  
Vol 22 (12) ◽  
pp. 6452
Author(s):  
Max Y. Zhang ◽  
George J. Dugbartey ◽  
Smriti Juriasingani ◽  
Alp Sener

Thiosulfate in the form of sodium thiosulfate (STS) is a major oxidation product of hydrogen sulfide (H2S), an endogenous signaling molecule and the third member of the gasotransmitter family. STS is currently used in the clinical treatment of acute cyanide poisoning, cisplatin toxicities in cancer therapy, and calciphylaxis in dialysis patients. Burgeoning evidence show that STS has antioxidant and anti-inflammatory properties, making it a potential therapeutic candidate molecule that can target multiple molecular pathways in various diseases and drug-induced toxicities. This review discusses the biochemical and molecular pathways in the generation of STS from H2S, its clinical usefulness, and potential clinical applications, as well as the molecular mechanisms underlying these clinical applications and a future perspective in kidney transplantation.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 848 ◽  
Author(s):  
Karolina Wojtacha-Rychter ◽  
Adam Smoliński

The self-heating phenomenon of coal leads to work safety hazards in underground mining. The quantitative analysis of gaseous products in mine atmosphere constitutes one of the detection methods of advanced coal heating. The article presents the results of tests on CO, CO2, and H2 emissions during simulated heating of coal in the temperature range of 323–523 K. The oxidation of 15 Polish coals of various carbon contents was performed using a flow reactor technique. A chromatography method was applied to measure the changes of oxidation products concentrations with the increase of temperature. It has been determined that all the tested gases were generated at the initial temperature. The collected data indicated that CO2 was a major oxidation product in the entire temperature range, while the amounts of H2 produced did not exceed 0.49% volume. At the temperature of 323 K, the ratio of CO2/CO was in the range of 10–23 but along with the temperature increase the ratio range narrowed to 3–4. In this paper, a comparison of the physical-chemical properties of the tested coals and the emissions profile of the gases using, among others, the hierarchical clustering analysis showed that samples with higher oxygen, sulfur, and inertinite content as well as lower ash and carbon content formed larger amounts of fire gases.


2019 ◽  
Vol 56 (2) ◽  
pp. 330-336
Author(s):  
Adriana-Mariana Bors ◽  
Marius-Eduard Lungulescu ◽  
Nicoleta Oana Nicula (Butoi) ◽  
Alina-Ruxandra Caramitu ◽  
Iosif Lingvay

This paper shows the ageing study of some coatings and / or impregnation lacquers due to microbiological stress through fungal attack. Dielectric spectroscopy has shown that the dielectric losses of the investigated materials increase as result of microbiological ageing. The mean recorded increases are about 4 times for the alkyl-epoxy-melamine copolymer, 2 times for epoxy polymer and 1.5 times for urethane polymer in agreement with the mould coverage degree of about 20 %, 10 %, and 3 %, respectively. The fungal attack of the investigated polymers led to a decrease in volume resistivity of about 65 % for the alkyl-epoxy-melamine copolymer, 45 % for the epoxy polymer, and 14 % for polyurethane, in agreement with the increase of dielectric losses and degree of mold coverage of the samples. FTIR determinations have shown that fungal attack significantly increased the number of aliphatic -OH and C-H bonds and decreased the number of C-O bonds, respectively of C-O-C oxiran groups and C-C aromatic bonds. DSC thermograms recorded at different temperature ranges and the activation energies calculation for first major oxidation process indicate that after the fungal attack the thermooxidative reactivity of the investigated polymers increases.


2019 ◽  
Vol 124 (7) ◽  
pp. 4174-4185 ◽  
Author(s):  
Yan‐Li Wang ◽  
Wei Song ◽  
Wen Yang ◽  
Xin‐Chao Sun ◽  
Yin‐Dong Tong ◽  
...  

2018 ◽  
Vol 62 (2) ◽  
Author(s):  
Nelson Bravo Yumi ◽  
Patricio Espinoza ◽  
Enric Brillas ◽  
Juan Manuel Peralta Hernandez

<p>Nowadays, the increasing pollution of natural water effluents with herbicides, such as atrazine (ATZ, 2-chloro-4-ethylamino-6-isopropylamino-s-triazine), is an emerging problem that has not received the sufficient attention.  This work presents a study on ATZ degradation under an electrochemical advanced oxidation process (EAOP), such as anodic oxidation (AO).  The degradation of 175 mL of 10 and 40 mg L<sup>-1</sup> ATZ solutions was studied using Pt or BDD as anode. The assays were made with a stirred tank cell, using a supporting electrolyte of 0.050 mM of Na<sub>2</sub>SO<sub>4</sub> at pH 3.0 by applying 0.18, 0.27 and 0.37 A cm<sup>-2</sup>. The degradation rate increased by increasing current density, regardless of the anode employed. Greater amounts of ATZ were removed at higher organic load. The pesticide decay always obeyed a pseudo-first-order kinetics. A high degradation efficiency of 97%-99% was obtained by the more powerful AO-BDD process at 0.37 A cm<sup>-2</sup>. High performance liquid chromatography (HPLC) was used to follow the evolution of major oxidation products by AO-BDD, such as desethyl atrazine, desethyl desisopropyl atrazine and cyanuric acid.</p>


2018 ◽  
Vol 1547 ◽  
pp. 62-70 ◽  
Author(s):  
Joaquín Velasco ◽  
Arturo Morales-Barroso ◽  
M. Victoria Ruiz-Méndez ◽  
Gloria Márquez-Ruiz

2018 ◽  
Vol 118 (7) ◽  
pp. 3337-3390 ◽  
Author(s):  
Paul O. Wennberg ◽  
Kelvin H. Bates ◽  
John D. Crounse ◽  
Leah G. Dodson ◽  
Renee C. McVay ◽  
...  

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