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Phase oxidation

The electrophilic character of boron is again evident when we consider the oxida tion of organoboranes In the oxidation phase of the hydroboration-oxidation sequence as presented m Figure 6 11 the conjugate base of hydrogen peroxide attacks boron Hydroperoxide ion is formed m an acid-base reaction m step 1 and attacks boron m step 2 The empty 2p orbital of boron makes it electrophilic and permits nucleophilic reagents such as HOO to add to it... [Pg.254]

FIGURE 6 11 The oxidation phase in the hydroboration-oxidation of 1 methylcydo pentene... [Pg.255]

Niobium Oxides. The solubihty of oxygen in niobium obeys Henry s law to the solubiHty limit of the first oxide phase of 850—1300°C (123). The amount of oxygen in solution in niobium is 1.3 at. % at 850°C and nearly 2 at. % at 1000°C (124). Only three clearly defined anhydrous oxides of niobium have been obtained in bulk, ie, NbO, Nb02, and Nb20. Niobium monoxide, NbO, is obtained by hydrogen reduction of the pentoxide at... [Pg.28]

Examination of the metallic product (regulus) of such aluminothermically produced vanadium metal reveals the presence of oxide phases in the metal matrix. This suggests that there is a decreasing solubiHty for aluminum and oxygen below the melting point. To date, no purification processes have been developed that take advantage of the purification potential of this phenomenon. [Pg.383]

The nickel oxide modification obtained electrochemicaHy in KOH electrolyte contained potassium ion and its nickel oxidation level are higher than that of NiO 5. Conclusions regarding the transitions between the reduced and oxidized products within the two series are that the redox process was not reversible and although the oxidized phases of the P- and the y-nickel hydroxides differ in energy contents, differences in analyses and x-ray patterns are not significant. [Pg.545]

Fig. 1. Calcium carbide—calcium oxide phase diagram using A, pure CaC2, and B, technical-grade... Fig. 1. Calcium carbide—calcium oxide phase diagram using A, pure CaC2, and B, technical-grade...
After preparing a homogeneous solution of the precursors, powder precipitation is accompHshed through the addition of at least one complexing ion. For PLZT, frequently OH in the form of ammonium hydroxide is added as the complexing anion, which results in the formation of an amorphous, insoluble PLZT-hydroxide. Other complexing species that are commonly used are carbonate and oxalate anions. CO2 gas is used to form carbonates. Irrespective of the complexing anion, the precipitated powders are eventually converted to the desired crystalline oxide phase by low temperature heat treatment. [Pg.346]

In all of these oxide phases it is possible that departures from the simple stoichiometric composition occur dirough variation of the charges of some of the cationic species. Furthermore, if a cation is raised to a higher oxidation state, by the addition of oxygen to tire lattice, a conesponding number of vacant cation sites must be formed to compensate tire structure. Thus in nickel oxide NiO, which at stoichiomen ic composition has only Ni + cations, oxidation leads to Ni + ion formation to counterbalance the addition of extra oxide ions. At the same time vacant sites must be added to the cation lattice to retain dre NaCl sUmcture. This balanced process can be described by a normal chemical equation thus... [Pg.225]

The difference in stability between FeO and NiO is not as large as that between iron and copper oxides, and so the preferential oxidation of iron is not so marked in pentlandite. Furthermore, the nickel and iron monoxides form a continuous series of solid solutions, and so a small amount of nickel is always removed into die oxide phase (Table 9.2). [Pg.275]

Another example of the use of neutron diffraction to understand the role of atomic vacancies in producing a superconducting metal oxide phase is work that has been performed on Bao Kq 4fii03. This work demonstrates that at the synthesis temperature (700° C), under the proper conditions, oxygen vacancies are created to allow the formation of the parent phase with bismuth largely in the +3 oxidation state. The presence of the vacancies allows the incorporation of potassium in the... [Pg.656]

Boulesteix, C. (editor) (1998) Oxides Phase Transitions, Non-Stoichiometry, Superconductors in Key Engineering Materials, vol. 155-156. [Pg.148]

This section considers a number of extremely important structure types in which A1 combines with one or more other metals to form a mixed oxide phase. The most significant of these from both a theoretical and an industrial viewpoint are spinel (MgAl204) and related compounds, Na- -alumina (NaAlnOi ) and related phases, and tricalcium aluminate (Ca3Al20g) which is a major constituent of Portland cement. Each of these compounds raises points of fundamental importance in solid-state chemistry and each possesses properties of crucial significance to... [Pg.247]

Nonstoichiometric oxide phases are of great importance in semiconductor devices, in heterogeneous catalysis and in understanding photoelectric, thermoelectric, magnetic and diffusional properties of solids. They have been used in thermistors, photoelectric cells, rectifiers, transistors, phosphors, luminescent materials and computer components (ferrites, etc.). They are cmcially implicated in reactions at electrode surfaces, the performance of batteries, the tarnishing and corrosion of metals, and many other reactions of significance in catalysis. ... [Pg.644]

Finally, oxygen is soluble in metallic titanium up to a composition of TiOo.s with the oxygen atoms occupying octahedral sites in the hep metal lattice distinct phases that have been crystallographically characterized are TieO, TisO and Ti20. It seems likely that in all these reduced oxide phases there is extensive metal-metal bonding. [Pg.962]

Niobium and tantalum also form various oxide phases but they are not so extensive or well characterized as those of vanadium. Their pentoxides are relatively much more stable and difficult to reduce. As they are attacked by cone HF and will dissolve in fused alkali, they may perhaps... [Pg.982]

The dioxides of molybdenum (violet) and tungsten (brown) are the final oxide phases produced by reduction of the trioxides with hydrogen they have rutile structures sufficiently distorted to allow the formation of M-M bonds and concomitant metallic conductivity and diamagnetism. Strong heating causes disproportionation ... [Pg.1008]

No other oxide phases below MO2 have been established but a yellow hydroxide , precipitated by alkali from aqueous solutions of chromium(II), spontaneously evolves H2 and forms a chromium(III) species of uncertain composition. The sulfides, selenides and tellurides of this triad are considered on p. 1017. [Pg.1009]

BaAn" 03 (An = Th Am) all have the perovskite strueture and are obtained from the aetinide dioxide. In aeeord with normal redox behaviour, the Pa and U eompounds are only obtainable if O2 is rigorously exeluded, and the Am eompound if O2 is present. Aetinide dioxides also yield an extensive series of nonstoiehiometrie, mixed oxide phases in whieh a seeond oxide is ineorporated into the fluorite lattiee of the An02. The UO2/PUO2 system, for example, is of great importanee in the fuel of fast-breeder reaetors. [Pg.1269]

It is generally agreed that the four known oxide phases in the Pu-0 system are PU2O3 (hexagonal, La203 type), PuOi.52 (bcc), PuOl.61 Cfee, tentative), and Pu02 (fee, fluorite type). Above... [Pg.113]

See other pages where Phase oxidation is mentioned: [Pg.510]    [Pg.323]    [Pg.545]    [Pg.545]    [Pg.274]    [Pg.351]    [Pg.455]    [Pg.654]    [Pg.744]    [Pg.247]    [Pg.247]    [Pg.249]    [Pg.251]    [Pg.961]    [Pg.982]    [Pg.1260]    [Pg.25]    [Pg.284]    [Pg.967]    [Pg.978]    [Pg.1132]    [Pg.1134]    [Pg.1135]    [Pg.1135]    [Pg.307]    [Pg.751]    [Pg.144]   
See also in sourсe #XX -- [ Pg.106 ]



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1-Alkenes, liquid-phase oxidation

3-picoline liquid-phase oxidation

Acetaldehyde liquid phase oxidation

Amorphous oxide and hydroxide phases

Anthracene liquid phase oxidation

Anthracene vapor phase oxidation

Aqueous-phase oxidation

Arsenic from iron-oxide phases

Au-catalyzed liquid-phase oxidation

Benzyl liquid-phase oxidation

C-X-Y-Fragment (Nitrile Oxide on Solid Phase)

Catalyst oxide phase

Catalysts in liquid phase oxidations

Catalytic Oxidation by Nitrous Oxide in the Gas Phase

Catalytic liquid phase oxidations with

Cerium-molybdenum oxide phases

Chromium oxide phase diagrams

Chromium reagents two phase oxidation

Comparison of Aqueous-Phase S(IV) Oxidation Paths

Conjugated Reactions of Oxidation with Hydrogen Peroxide in the Gas Phase

Cuprous oxide metallic phase

Design of Well-Defined Active Sites on Crystalline Materials for Liquid-Phase Oxidations

Disulfides, liquid-phase oxidation

Fluorite-related oxide phases

Formation aqueous-phase oxidation pathway

Free radical reactions vapour-phase oxidation

Free radicals, liquid-phase chain oxidation

Gas phase, oxidation processes

Gas-Phase Oxidation with

Gas-Phase Selective Oxidation of Alcohols

Gas-Phase Selective Oxidation of Aliphatic Alkanes

Gas-Phase Selective Oxidation of Organic Compounds

Gas-phase oxidation

Gas-phase oxidation of carbon

Gas-phase oxidation of hydrocarbons

Gas-phase oxidation over metals

Gas-phase partial oxidation

Heterogeneous Catalysis of Liquid Phase Oxidations

High-Pressure Investigations of Magnetic Properties (Examples Laves Phases and Iron Oxides)

Homogeneous oxidation in the gas phase

Hydrocarbons liquid-phase oxidation

Hydrocarbons vapor-phase oxidation

Hydrous oxide solid-phase adsorbents

Hydrous oxide solid-phase adsorbents adsorbate

Influence of the Specific Oxide Support Phase

Inhibited liquid-phase oxidation

Lead oxides, crystalline phases

Liquid Phase Aerobic Oxidation Catalysis: Industrial Applications and Academic Perspectives

Liquid Phase Oxidation Reactions Catalyzed by Polyoxometalates

Liquid phase oxidation process

Liquid phases, high-temperature corrosion oxidation reaction

Liquid-Phase Catalytic Oxidations with Perovskites and Related Mixed Oxides

Liquid-Phase Oxidation of Alkenes

Liquid-Phase Oxidation of MEP with Nitric Acid

Liquid-Phase Oxidation of Nicotine with Permanganate, Chromic Acid, etc

Liquid-Phase Oxidations with Hydrogen Peroxide and Molecular Oxygen Catalyzed by Polyoxometalate-Based Compounds

Liquid-Phase Selective Oxidation of Organic Compounds

Liquid-phase Oxidation over Heterogeneous Catalysts

Liquid-phase catalytic oxidations

Liquid-phase chain oxidation, equations

Liquid-phase co-oxidations

Liquid-phase olefin oxidation

Liquid-phase oxidation of hydrocarbon

Liquid-phase oxidation of secondary

Liquid-phase oxidation reactions

Liquid-phase oxidation with oxidizing compounds

Liquid-phase oxidation with oxygen

Liquid-phase oxidation, homogeneous catalysis

Liquid-phase selective oxidation catalysts

Liquid-phase selective oxidations

Liquid-phase, oxidation, organic

Liquids liquid-phase oxidation

Lower oxides stable phases

MIEC oxides single-phase

Magneli phase titanium oxide

Manganese Oxide Phases

Manganese oxides, crystalline phases

Metal oxide-based phases

Metal-Catalyzed Liquid-Phase Auto-oxidation

Metal-ion catalyzed, liquid-phase oxidation

Metal-oxide phase

Metastable mixed oxide phase synthesis

Methyl liquid-phase oxidation

Mixed metal amorphous and spinel phase oxidation catalysts derived from carbonates

Mixed oxides, phase equilibria

Mixed oxides, phase equilibria metal-oxygen

Mixed oxides, structure types phases

Mixed-phase oxide pigments

Nanostructured phases oxidation

Naphthols oxidation, liquid phase

Nitric oxide aqueous phase reactions

Non-oxide phases

Nonstoichiometric phases, lead oxides

Osmium liquid phase oxidation

Outside vapor-phase oxidation

Overview on Gallium Oxide Nitride Phases

Oxidation Reactions in the Gas Phase

Oxidation Vapor phase processes

Oxidation absorbance changes’ phases during

Oxidation by Nitrous Oxide in the Gas Phase

Oxidation by Ozone in the Aqueous Phase

Oxidation in gas-phase

Oxidation in liquid-phase

Oxidation in the Aqueous Phase

Oxidation in the Gas Phase

Oxidation in the Solid Phase

Oxidation liquid-phase

Oxidation liquid-phase alcohol

Oxidation phase transfer-catalyze

Oxidation phase-transfer-catalysed

Oxidation under phase-transfer condition

Oxidation, troposphere aqueous phase

Oxidative cleavage phase transfer catalysis

Oxidative phase

Oxidative phase

Oxide Composition—Phase Diagrams

Oxide and Hydroxide Systems with Poorly Crystalline Phases

Oxide liquid phase deposition

Oxide phases

Oxide phases

Oxide phases phase diagrams

Oxides gas phase

Oxides phase composition

Oxides sesqui, phase transformation

Oxygen Ionic Transport in Acceptor-Doped Oxide Phases Relevant Trends

Oxygen acceptor-doped oxide phases

Paraffins liquid phase oxidations

Partial oxidation phases

Pentose phosphate pathway oxidative phase

Perhalocarbons, Gas Phase Oxidation of (Heicklen)

Phase I Oxidations

Phase I oxidation, reduction, and

Phase I oxidative reaction

Phase I reactions oxidation

Phase Oxidation Processes for Hydrogen Sulfide Removal

Phase Oxidation Techniques

Phase Oxidation of Alkenes

Phase Selective Oxidation of Organic Compounds

Phase Wacker-type oxidation

Phase aluminium oxide

Phase diagram mixed oxides

Phase diagrams oxide

Phase diagrams vanadium oxide

Phase ternary oxide

Phase transfer catalysis alkene oxidation

Phase transfer oxidation

Phase-supported oxidant

Phase-transfer catalytic oxidation

Phase-transfer catalytic oxidation medium

Phases aluminum oxide

Physical and Chemical Steps in Aqueous-Phase Oxidation

Plutonium oxides phase composition

Polymer-assisted solution phase synthesis oxidizing polymers

Polyoxometalate liquid phase oxidation

Potential Future Solutions for PO Synthesis Direct Gas-Phase Oxidation of Propene with Oxygen (DOPO)

Potential Future Solutions for PO Synthesis Gas-Phase Hydro-oxidation of Propene with Oxygen and Hydrogen (HOPO)

Precursor Approach for Gallium Oxide Nitride Phases

Rate Constants for Reactions in Gas-phase Hydrocarbon Oxidation

Reactor Concepts for Aerobic Liquid Phase Oxidation Microreactors and Tube Reactors

Research on liquid-phase oxidation

Second phase particles oxides

Selective Oxidation Vapor Phase

Silica phases among oxides

Simple oxides, structural and electronic phase transitions

Single-phase oxide solid-solutions

Solid Phases Hydroxides, Oxyhydroxides, Oxides

Solid phase oxidations

Solid state oxide phases

Solid-phase synthesis oxidation reactions

Stationary phases inorganic oxides

Stationary phases metal oxide-based

Stirred reactor, liquid phase oxidation

Sulfur aqueous-phase oxidants

Sulfur aqueous-phase oxidation

Sulfur dioxide aqueous-phase oxidation

Supercritical water oxidation vapor phase

Supported Metal Nanoparticles in Liquid-Phase Oxidation Reactions

Supported liquid phase catalyst SO2 oxidation mechanism

Supported liquid-phase oxidation reactions

Surface oxide electrochemical phase

Ternary and more complex oxide phases

Thallium oxide phase

Transition manganese oxide phases

Two-phase oxidations

Unconventional Oxidants for Gas-Phase Oxidations

Vapor phase oxidation reactions

Vapor phase oxidation silica

Vapor-phase oxidation

Vapor-phase oxidation inhibitors

Vapor-phase oxidation of aromatic hydrocarbons

Zirconium oxide, phase transitions

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