Identification of Fe (IV) in oxides by chemical test methods

2020 ◽  
Vol 86 (6) ◽  
pp. 5-13
Author(s):  
N. V. Barkovskii
Keyword(s):  
Redox Reactions ◽  
Alkaline Earth ◽  
Solid Phase ◽  
Test Methods ◽  
Alkaline Media ◽  
Chemical Test ◽  
Phase Synthesis ◽  
Organic Reagents ◽  
Standard Redox Potential ◽  
First Time

A comparative analysis of the behavior of oxides containing Fe (III) and Fe (IV) in redox reactions with organic and inorganic reagents has been carried out. SrFeO3-x oxide obtained by solid-phase synthesis from SrCO3 and Fe2O3 has been an object to develop test methods. It has been shown that Fe (IV) exhibits the properties of a stronger oxidizer than Fe (III), thus providing a set of reagents which enable identification of Fe (IV): hydrobromic acid, Fe2+ complex with V (IV), and Mn (II) salts, and organic reagents, namely, amines (diphenylamine, o-tolidine, benzidine) and dyes (methyl red). Potentiometric method proved stronger oxidative properties of Fe (IV) compared to Fe (III) revealed in different character of changes in EMF during dissolution of the corresponding oxides in HCl. SrFeO3–x oxide does not oxidize Mn (II) to Mn (VII), Cr (III) to Cr (VI), Ce (III) to Ce (IV) in acidic media, and Cu (II) to Cu (III) in alkaline media. Since the oxide under study oxidize Cl– = 1.3583 V) and Br– = 1.087 V) ions to the corresponding halogens, but does not oxidize Mn2+ to = 1.51 V), an estimated value of the standard redox potential is ~1.4 V. We have developed for the first time a system of analytical tests for differentiation of Fe (IV) and Fe (III) which can provide monitoring of the synthesis of complex oxides and phase formation in the systems containing iron, alkali and alkaline earth metals.

scholarly journals Твердофазные реакции и фазовые превращения в наноразмерной пленочной структуре висмут/селен

2018 ◽  
Vol 52 (8) ◽  
pp. 823
Author(s):  
В.Я. Когай ◽  
Г.М. Михеев
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Phase Transformations ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Film Structure ◽  
Phase Synthesis ◽  
Crystallite Sizes ◽  
Solid Phase Reactions ◽  
First Time

AbstractExperimental results of a study concerned with solid-phase reactions and phase transformations in a Bi/Se nanoscale film structure under heat treatment in vacuum are presented. Nanocrystalline Bi2Se3, BiSe, and Bi_4Se_3 films are obtained for the first time by solid-phase synthesis at various ratios between the Bi and Se layer thicknesses. The phase-transformation temperatures at which Se, BiSe, and Bi4Se3 crystalline phases are formed are determined. The average crystallite sizes in the Bi_2Se_3, BiSe, and Bi_4Se_3 films are found to be 21, 23, and 33 nm, respectively.

A Different Approach to the EGFR Inhibitor Gefitinib Involving Solid-Phase Synthesis

Synlett ◽  
2018 ◽  
Vol 29 (10) ◽  
pp. 1346-1350 ◽  
Author(s):  
Luísa Carvalho ◽  
André Sequeira ◽  
Ana Lourenço ◽  
Luísa Ferreira ◽  
Paula Branco ◽  
...  
Keyword(s):  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Solid Support ◽  
Egfr Inhibitor ◽  
Phase Synthesis ◽  
Synthetic Strategy ◽  
Colorimetric Assays ◽  
First Time ◽  
Synthesis Approach

An efficient solid-phase synthesis approach is here reported for the first time to prepare the EGFR inhibitor Gefitinib. The five-step synthetic strategy used FMP resin as the solid support, and FTIR and colorimetric assays were used to track the reaction’s progress. Gefitinib was obtained with an overall yield of 40%.

Effect of Mn Doping on Magnetic and Dielectric Properties of Bi2Sn2O7

2015 ◽  
Vol 233-234 ◽  
pp. 105-108 ◽  
Author(s):  
Lubov V. Udod ◽  
Sergey S. Aplesnin ◽  
Maxim N. Sitnikov ◽  
Evgenii V. Eremin ◽  
Maxim S. Molokeev
Keyword(s):  
Electrical Resistance ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Phase Synthesis ◽  
Martensitic Phase Transitions ◽  
Polymorphic Modifications ◽  
Temperature Dependences ◽  
Magnetic And Dielectric Properties ◽  
First Time ◽  
Magnetic Dielectric

The Bi2(Sn0.95Mn0.05)2O7 compound existing simultaneously in two polymorphic modifications, namely, orthorhombic and cubic has been synthesized for the first time by solid-phase synthesis. The magnetic, dielectric and electrical properties of the compound have been studied. Anomalies in the temperature dependences of the electrical resistance and magnetic propoties have been found. These features are explained as martensitic phase transitions.

scholarly journals STUDY OF SORPTION OF RHENIUM IONS ON SOLID EXTRAGENTS

2021 ◽  
pp. 3-10
Keyword(s):  
Sulfuric Acid ◽  
Solid Phase ◽  
Sulfuric Acid Concentration ◽  
Sorption Process ◽  
Organic Reagent ◽  
Organic Reagents ◽  
Static Conditions ◽  
Sulfuric Acid Solutions ◽  
First Time ◽  
Kinetics Of

In this work, the aim is to study the possibility of extracting rhenium from sulfuric acid solutions by sorption of impregnated sorbents based on polystyrene-divinylbenzene (MN202) and an organic reagent MAB (2-amino-1-methylbenzimidazole).New sorbent based on MN202 (Purolite) impregnated with organic reagents have been obtained and investigated. The sorbent characteristics determined using SEM, XRD and FTIR methods. The optimal conditions for the sorption of rhenium (VII) ions for the "element-sorbent" systems have been established. Under static conditions, the sorption of rhenium on impregnated sorbents in a sulfuric acid solution was studied in the periodic system with respect to the contact time, sulfuric acid concentration, the ratio of the solid phase to liquid, and the initial concentration of rhenium. For the first time, the kinetics of sorption of rhenium (VII) ions with the obtained solid extractants has been studied. The kinetic parameters of the chemical reaction on the surface of the impregnate have been determined. Based on the processing of the integral kinetic curves of sorption, it was found that the sorption process proceeds in accordance with second-order models.

scholarly journals Solid-phase Synthesis of Tetrapeptide on 2-Chlorotrityl Chloride Resin by Using Benzotriazol-1-yl-oxytripyrrolidinophosphonium Hexafluorophosphate as Coupling Reagent

2016 ◽  
Vol 2 (2) ◽  
pp. 85-90
Author(s):  
Rani Maharani ◽  
Nuruzzahra Ammatillah ◽  
Gunawan Gunawan ◽  
Ace Tatang Hidayat
Keyword(s):  
Solid Phase ◽  
Coupling Reaction ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Protecting Group ◽  
Phase Synthesis ◽  
Coupling Reagent ◽  
Cleavage Step ◽  
First Time ◽  
Fmoc Strategy

Tetrapeptide, OH-Pro-Ala-Gly-Tyr-NH2, was successfully synthesised on 2-chlorotrityl chloride resin by taking advantage of PyBOP (benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate) as coupling reagent. The selection of the peptide as the target of synthesis was due to its interesting bioactivity as antioxidant. The synthesis was undertaken with Fmoc strategy, where Fmoc-proline was added onto the resin at the first place. It is known from the literature that proline can resist from rasemisation when  it was attached on the resin at the first time. Fmoc deprotection step was carried out by employing 20% piperidine in DMF and the reaction mixture was shaken for 30 minutes. Once the proline attached, the next step was to attach amino acids, alanine (Ala), glycine (Gly) and tyrosine(Tyr), subsequently onto the resin until tetrapeptidyl resin was constructed on the resin.  Hydroxyl group of Tyr was protected with t-butyl, which is TFA-labiled. Coupling reaction was undertaken by mixing the amino acid and PyBOP in a mixture of dichloromethane and DMF (1:1) and in the presence of basic DIPEA. Resin cleavage step was carried out by using 95% TFA in water, where t-butyl protecting group on the side chain of Tyr was cleaved at the same time. The analytical RP-HPLC of the final product showed a single peak at 21.9 minutes (20-90% of acetonitrile in water with 0.1% of TFA during 30 minutes), indicating that each coupling has given a good coupling performance and resulting in a pure product. The desired product showed the correct molecular weight with m/z 407.2 [M+H]+ and 429.2 [M+Na]. DOI: http://dx.doi.org/10.15408/jkv.v0i0.4055

PREPARATION AND CHARACTERIZATION OF ELECTRIC ZAO NANOPARTICLES

NANO ◽  
2010 ◽  
Vol 05 (04) ◽  
pp. 215-220 ◽  
Author(s):  
HAO-WEI SHI ◽  
HONG-ZHEN XIE ◽  
JIN-KU LIU ◽  
YAN WANG
Keyword(s):  
Seed Germination ◽  
Root Growth ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Synthesis Method ◽  
Strong Inhibition ◽  
Phase Synthesis ◽  
White Good ◽  
First Time

The white good dispersion zinc aluminium oxide (ZAO) nanoparticles were efficiently prepared by solid phase synthesis method. The morphologies, structures, photoelectricity of the ZAO nanoparticles and the thermochemistry behavior of the precursor were analyzed by TEM, XRD, UV-vis and TG, etc. The phytotoxicity properties of the ZAO nanoparticles were researched for the first time. The results show that the ZAO nanoparticles have a strong inhibition of seed germination and root growth. The biological toxicity of ZAO nanoparticle reduces along with the enlargement of nanoparticle size.

scholarly journals Исследование кинетики гибели неравновесных носителей заряда в четверных соединениях меди Cu-=SUB=-2-delta-=/SUB=-NiSnS-=SUB=-4-=/SUB=- (0≤delta≤0.2)

2021 ◽  
Vol 55 (12) ◽  
pp. 1176
Author(s):  
М.В. Гапанович ◽  
Е.В. Рабенок ◽  
Б.И. Голованов ◽  
Д.М. Седловец ◽  
Г.Ф. Новиков
Keyword(s):  
Crystal Lattice ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Time Resolved ◽  
Phase Synthesis ◽  
Recombination Processes ◽  
Bimolecular Recombination ◽  
The Times ◽  
First Time ◽  
Kinetics Of

By solid-phase synthesis from elemental Cu, Ni, Sn, and S samples Cu2 - δNiSnS4 was prepared . The parameters of their crystal lattice have been refined. The lifetimes of photogenerated current carriers in Cu2 - δNiSnS4 were estimated for the first time by the contactless time-resolved microwave photoconductivity method. This times turned out to be τ ≈ 7 ns, which is comparable with the literature data for the times in kesterites CZTS. Herewith, in kinetics of loses of photogenerated cureent carriers is observed predominance of bimolecular recombination processes over capture processes.

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