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Difluorodioxirane
Difluorodioxirane (CF2O2) is a rare, stable member of the dioxirane family, known for a single oxygen-oxygen bond (O-O). Unlike most dioxiranes that decompose quickly, difluorodioxirane is surprisingly stable at room temperature, making it potentially useful for further research and applications. Synthesis Difluorodioxirane was first synthesised by Russo and DesMarteau in 1993 by treating fluorocarbonyl hypofluorite (FCOOF) with X2 (= F2, Cl2 or ClF) over pelletized CsF in a flow system. It also likely exists as a possible intermediate in reactions involving other fluorine-containing compounds. Properties Unlike most dioxiranes that decompose quickly, difluorodioxirane is surprisingly stable at room temperature due to the stabilising interacton of two fluorine atoms with the ring. This effect makes the O-O bond less reactive and more stable compared to other dioxiranes. The central F–C–F angle is 109°, approximately a tetrahedral angle. Difluorodioxirane is known fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioxirane
In chemistry, dioxirane (systematically named dioxacyclopropane, also known as methylene peroxide or peroxymethane) is an organic compound with formula . The molecule consists of a ring with one methylene and two oxygen atoms. It is of interest as the smallest cyclic organic peroxide, but otherwise it is of little practical value. Synthesis Dioxirane is highly unstable and the majority of studies of it have been computational; it has been detected during the low temperature (–196 °C) reaction of ethylene and ozone, although even at these temperatures such a mixture can be explosive. Its formation is thought to be radical in nature, preceding via a Criegee intermediate. Microwave analysis has indicated C-H, C-O and O-O bond lengths of 1.090, 1.388 and 1.516 Å respectively. The very long and weak O-O bond (cf. hydrogen peroxide O-O = 1.47 Å) is the origin of its instability. Other dioxiranes Beyond the parent dioxirane, which is mainly of theoretical interest, more c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethyldioxirane
Dimethyldioxirane (DMDO) is the organic compound with the formula . It is the dioxirane derived from acetone and can be viewed as the monomer of acetone peroxide. It is a powerful selective oxidizing agent that finds some use in organic synthesis. It is known only in the form of a dilute solution, usually in acetone, and hence the properties of the pure material are largely unknown. Synthesis DMDO is not commercially available because of chemical instability. DMDO can be prepared as dilute solutions (~0.1 M) by treatment of acetone with potassium peroxymonosulfate , usually in the form of Oxone (2KHSO5·KHSO4·K2SO4). : The preparation of DMDO is rather inefficient (typical yields < 3%) and typically only yields a relatively dilute solution in acetone (only up to approximately 0.1 M). This is tolerable as preparation uses inexpensive substances: acetone, sodium bicarbonate, and oxone. Cold solutions (−10 to −20 °C) of DMDO are stable for days. Decomposition is accelerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimesityldioxirane
Dimesityldioxirane is a substituted dioxirane with two mesityl groups attached to the dioxirane carbon. It is a colorless crystalline substance stable in its solid state around -20 °C. Structure The molecule possesses approximately C2 symmetry and the mesityl groups are twisted by 54.2°. The bulky mesityl groups cause steric strain which is reduced by increase in R1–C–R2 angle from 117° in dioxirane to 119.2° in dimesityldioxirane. The mesityl groups also rotate about the single bond, consequently reducing steric repulsions further. Synthesis and Uses Dimesityldioxirane was first isolated at room temperature in pure as well as in solution form in 1994. It was synthesised by irradiation of its diazo derivative in trichlorofluoromethane at 183K to form , followed by oxidation. The synthesis had a yield of 50%. It can mainly be used as an oxidizing agent but is less oxidizing than other dioxiranes due to its stability. See also * Difluorodioxirane *Dimethyldioxir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxide
In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ethers. They are produced on a large scale for many applications. In general, low molecular weight epoxides are colourless and nonpolar, and often volatile. Nomenclature A compound containing the epoxide functional group can be called an epoxy, epoxide, oxirane, and ethoxyline. Simple epoxides are often referred to as oxides. Thus, the epoxide of ethylene (C2H4) is ethylene oxide (C2H4O). Many compounds have trivial names; for instance, ethylene oxide is called "oxirane". Some names emphasize the presence of the epoxide functional group, as in the compound ''1,2-epoxyheptane'', which can also be called ''1,2-heptene oxide''. A polymer formed from epoxide precursors is called an ''epoxy''. However, few if any of the epoxy groups i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidizing Agents
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ''electron donor''). In other words, an oxidizer is any substance that oxidizes another substance. The oxidation state, which describes the degree of loss of electrons, of the oxidizer decreases while that of the reductant increases; this is expressed by saying that oxidizers "undergo reduction" and "are reduced" while reducers "undergo oxidation" and "are oxidized". Common oxidizing agents are oxygen, hydrogen peroxide, and the halogens. In one sense, an oxidizing agent is a chemical species that undergoes a chemical reaction in which it gains one or more electrons. In that sense, it is one component in an oxidation–reduction (redox) reaction. In the second sense, an oxidizing agent is a chemical species that transfers electronegative atoms, usually oxygen, to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Peroxides
In organic chemistry, organic peroxides are organic compounds containing the peroxide functional group (). If the R′ is hydrogen, the compounds are called hydroperoxides, which are discussed in that article. The O−O bond of peroxides easily breaks, producing free radicals of the form (the dot represents an unpaired electron). Thus, organic peroxides are useful as radical initiator, initiators for some types of polymerization, such as the Acrylic resin, acrylic, unsaturated polyester, and vinyl ester resins used in glass-reinforced plastics. methyl ethyl ketone peroxide, MEKP and benzoyl peroxide are commonly used for this purpose. However, the same property also means that organic peroxides can explosively combust. Organic peroxides, like their inorganic counterparts, are often powerful bleaching agents. Types of organic peroxides Organic peroxides are classified (i) by the presence or absence of a hydroxyl () terminus and (ii) by the presence of alkyl vs acyl substituents. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shi Epoxidation
The Shi epoxidation is a chemical reaction described as the asymmetric epoxidation of alkenes with oxone (potassium peroxymonosulfate) and a fructose-derived catalyst (1). This reaction is thought to proceed via a dioxirane intermediate, generated from the catalyst ketone by oxone (potassium peroxymonosulfate). The addition of the sulfate group by the oxone facilitates the formation of the dioxirane by acting as a good leaving group during ring closure. It is notable for its use of a non-metal catalyst and represents an early example of organocatalysis. History The reaction was first reported by Yian Shi (史一安, pinyin: Shǐ Yī-ān) is derived from D-fructose and has a stereogenic center close to the reacting center (ketone)- the rigid six-membered ring structure of the catalyst and adjacent quaternary ring group minimizes epimerization of this stereocenter. Oxidation by the active dioxirane catalyst takes place from the si-face, due to steric hindrance of the opposing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxy Group
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxylation
In chemistry, hydroxylation refers to the installation of a hydroxyl group () into an organic compound. Hydroxylations generate alcohols and phenols, which are very common functional groups. Hydroxylation confers some degree of water-solubility. Hydroxylation of a hydrocarbon is an oxidation, thus a step in degradation. Biological hydroxylation In biochemistry, hydroxylation reactions are often facilitated by enzymes called hydroxylases. These enzymes insert an O atom into a bond. Typical stoichiometries for the hydroxylation of a generic hydrocarbon are these: : : Since itself is a slow and unselective hydroxylating agent, catalysts are required to accelerate the pace of the process and to introduce selectivity. Hydroxylation is often the first step in the degradation of organic compounds in air. Hydroxylation is important in detoxification since it converts lipophilic compounds into water-soluble (hydrophilic) products that are more readily removed by the kidneys or liver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxide
In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ethers. They are produced on a large scale for many applications. In general, low molecular weight epoxides are colourless and nonpolar, and often volatile. Nomenclature A compound containing the epoxide functional group can be called an epoxy, epoxide, oxirane, and ethoxyline. Simple epoxides are often referred to as oxides. Thus, the epoxide of ethylene (C2H4) is ethylene oxide (C2H4O). Many compounds have trivial names; for instance, ethylene oxide is called "oxirane". Some names emphasize the presence of the epoxide functional group, as in the compound ''1,2-epoxyheptane'', which can also be called ''1,2-heptene oxide''. A polymer formed from epoxide precursors is called an ''epoxy''. However, few if any of the epoxy groups i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
