OxygenOxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2.
AlkylationAlkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins.
CatalysisCatalysis (kəˈtæləsɪs) is the process of change in rate of a chemical reaction by adding a substance known as a catalyst (ˈkætəlɪst). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst.
Allotropes of oxygenThere are several known allotropes of oxygen. The most familiar is molecular oxygen (), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen. Another is the highly reactive ozone (). Others are: Atomic oxygen (), a free radical. Singlet oxygen (O2*), one of two metastable states of molecular oxygen. Tetraoxygen (), another metastable form. Solid oxygen, existing in six variously colored phases, of which one is octaoxygen (,red oxygen) and another one metallic (ζ-oxygen).
Metal–organic frameworkMetal–organic frameworks (MOFs) are a class of compounds consisting of metal clusters (also known as SBUs) coordinated to organic ligands to form one-, two-, or three-dimensional structures. The organic ligands included are sometimes referred to as "struts" or "linkers", one example being 1,4-benzenedicarboxylic acid (BDC). More formally, a metal–organic framework is an organic-inorganic porous extended structure. An extended structure is a structure whose sub-units occur in a constant ratio and are arranged in a repeating pattern.
SiliconSilicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium are below it. It is relatively unreactive. Because of its high chemical affinity for oxygen, it was not until 1823 that Jöns Jakob Berzelius was first able to prepare it and characterize it in pure form.
Solid oxygenSolid oxygen forms at normal atmospheric pressure at a temperature below 54.36 K (−218.79 °C, −361.82 °F). Solid oxygen O2, like liquid oxygen, is a clear substance with a light sky-blue color caused by absorption in the red part of the visible light spectrum. Oxygen molecules have attracted attention because of the relationship between the molecular magnetization and crystal structures, electronic structures, and superconductivity. Oxygen is the only simple diatomic molecule (and one of the few molecules in general) to carry a magnetic moment.
WüstiteWüstite (FeO) is a mineral form of iron(II) oxide found with meteorites and native iron. It has a grey colour with a greenish tint in reflected light. Wüstite crystallizes in the isometric-hexoctahedral crystal system in opaque to translucent metallic grains. It has a Mohs hardness of 5 to 5.5 and a specific gravity of 5.88. Wüstite is a typical example of a non-stoichiometric compound. Wüstite was named after Fritz Wüst (1860–1938), a German metallurgist and founding director of the Kaiser-Wilhelm-Institut für Eisenforschung (presently Max Planck Institute for Iron Research GmbH).
Chemical reactionA chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.
Solid-state chemistrySolid-state chemistry, also sometimes referred as materials chemistry, is the study of the synthesis, structure, and properties of solid phase materials. It therefore has a strong overlap with solid-state physics, mineralogy, crystallography, ceramics, metallurgy, thermodynamics, materials science and electronics with a focus on the synthesis of novel materials and their characterization. A diverse range of synthetic techniques, such as the ceramic method and chemical vapour depostion, make solid-state materials.
