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Oxidation chemistry of phenylenediamines
The oxidation chemistry of phenylenediamines describes how the three benzenediamine isomers oxidize stepwise through semiquinonediimine radicals and quinonediimines, reactions underlying hair dyeing, color photography, and toxicity problems.
Oxidation state
Oxidation state, also called oxidation number, is the charge an atom would carry after ionic approximation of its bonds, defined by IUPAC in 2016 and written as Roman numerals in chemical names.
Oxidative addition
Oxidative addition, also called oxidative insertion, is an organometallic reaction in which a metal complex inserts into a covalent bond, raising its oxidation state by two.
Oxidative Coupling
Oxidative cross-coupling is a named synthetic method that forms bonds between two nucleophilic partners, usually C–H bonds, with an oxidant accepting the released electrons, avoiding prefunctionalization steps.
Oxidative coupling of methane
Oxidative coupling of methane (OCM) is a catalytic reaction that converts methane directly to ethylene and ethane over oxygen at 700–850 °C, reported by G. Keller in 1982.
Oxidative dehydrogenation of propane on hexagonal boron nitride
Oxidative dehydrogenation of propane on hexagonal boron nitride (h-BN) is a metal-free catalytic route to propene with low COx formation, first reported in 2016 by the Hermans group in Wisconsin.
Oxidative depolymerization of plastics
Oxidative depolymerization of plastics is a chemical recycling strategy that uses oxygen or oxidants to cleave polymer chains, yielding oxygenated chemicals such as dicarboxylic and benzoic acids.
Oxidative Heck reaction
The oxidative Heck reaction, also known as the dehydrogenative Heck or Fujiwara-Moritani reaction, is a Pd(II)-catalyzed carbon-carbon coupling first reported by Fujiwara and Moritani in 1967.
Oxidative lignin depolymerization
Oxidative lignin depolymerization is the chemical breakdown of lignin, the aromatic polymer of plant cell walls, using oxidants like oxygen and hydrogen peroxide to produce aromatic chemicals, chiefly vanillin.
Oxidative polymerization
Oxidative polymerization is a chemical synthesis method in which an oxidizing agent converts monomers such as aniline, pyrrole, and thiophene derivatives into conjugated conducting polymers used in batteries, sensors, and coatings.
Oxidative pyrolysis
Oxidative pyrolysis is a thermal analysis method in which solid fuels like coal and biomass are heated in air so pyrolysis and partial combustion overlap.
Oxide
An oxide is a binary chemical compound of oxygen with only one other element, such as CO₂ or H₂O, classified as acidic, basic, amphoteric, or neutral.
Oxide classification
Oxide classification is the sorting of oxides, binary compounds of oxygen with another element, into acidic, basic, amphoteric, and neutral families, with further categories for peroxides, superoxides, and mixed oxides.
Oxide interface magnetism
Oxide interface magnetism is magnetic order at the atomically sharp boundary between two non-magnetic oxide insulators, canonically the LaAlO3/SrTiO3 interface, whose reported ferromagnetism remains disputed as intrinsic or an artifact.
Oxide interface superconductivity
Oxide interface superconductivity is superconductivity that appears only within a few nanometers of the boundary between two insulating oxides, such as LaAlO₃/SrTiO₃, and can be tuned by electrostatic gating.
Oxide scale
Oxide scale is the layer of iron oxides, chiefly wüstite, magnetite, and hematite, that forms on iron and steel at high temperature, especially during hot rolling.
Oxide thermoelectrics
Oxide thermoelectrics are thermoelectric materials based on metal oxides that convert temperature gradients into electricity, studied as stable, low-cost alternatives to alloys like PbTe, though with lower efficiency.
Oxide-derived copper
Oxide-derived copper (OD-Cu) is a nanocrystalline copper electrocatalyst made by reducing copper oxide, first reported in 2014 at Stanford for converting carbon dioxide into ethylene, ethanol, and acetate.
Oxide-derived copper catalysts
Oxide-derived copper (OD-Cu) is a copper electrocatalyst prepared by reducing a copper oxide precursor, best known for converting carbon dioxide into ethylene and ethanol at lower overpotentials than metallic copper.
Oxide-derived copper for CO2 reduction
Oxide-derived copper CO2 reduction catalyst, or OD-Cu, is a copper electrocatalyst made by oxidizing then reducing copper; the roughened, defect-rich surface boosts selectivity for multi-carbon products like ethylene and ethanol.
Oxide-derived copper for CO2-to-ethylene
Oxide-derived copper (OD-Cu) is copper prepared by oxidation followed by electrochemical reduction, producing a roughened, defect-rich surface that converts CO2 to multicarbon products, especially ethylene, more selectively than pristine copper.
Oxide-derived silver catalysts
Oxide-derived silver (OD-Ag) catalysts are silver electrocatalysts prepared by oxidizing silver and reducing it back, leaving a nanostructured surface that converts CO2 to carbon monoxide more selectively.
Oxide-mediated oxygen reduction mechanism on platinum
The oxide-mediated oxygen reduction mechanism on platinum holds that reduction of a thin surface oxide, not adsorbate binding alone, determines the oxygen reduction reaction's overpotential on polycrystalline platinum.
Oxide-zeolite (OXZEO) syngas-to-olefins
Oxide-zeolite (OXZEO) syngas-to-olefins is a catalytic process, introduced in 2016 at the Dalian Institute of Chemical Physics, that converts synthesis gas directly into ethylene, propylene, and butenes.
Oxidizing agent
An oxidizing agent, also called an oxidant or oxidizer, is a substance that gains electrons in a reaction and is itself reduced; fluorine is the strongest common example.
Oxime
An oxime is an organic compound of structure R₂C=NOH, formed when an aldehyde or ketone condenses with hydroxylamine; its best-known reaction is the Beckmann rearrangement, used to make the nylon-6 precursor caprolactam.
Oxime ester
An oxime ester is an organic compound in which an oxime's oxygen atom is acylated, widely used as a radical precursor in organic synthesis and as a photoinitiator.
Oxime ester N–O bond activation
Oxime ester N–O bond activation is the deliberate cleavage of an oxime ester's weak nitrogen–oxygen bond, generating iminyl radicals used to build N-heterocycles and functionalize C–H bonds.
Oxindole
Oxindole, also called 2-oxindole or indolin-2-one, is a bicyclic aromatic organic compound first synthesized by Adolf von Baeyer in 1878 whose derivatives are widely used in medicinal chemistry, especially as kinase inhibitors for cancer treatment.
Oxisols
Oxisols, known as Ferralsols in the World Reference Base, are the most highly weathered of the twelve USDA soil orders, forming in hot, humid tropics with low natural fertility.