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Azines (heterocycles)
Azines are a functional class of organic compounds with the connectivity RR'C=N-N=CRR'. These compounds are the product of the condensation of hydrazine with ketones and aldehydes, although in practice they are often made by alternative routes. Ketazines are azines derived from ketones. For example, acetone azine is the simplest ketazine. Aldazines are azines derived from aldehydes. Preparation The usual method of industrial production is the peroxide process, starting from the ketone, ammonia, and hydrogen peroxide. : In the laboratory, azines are typically prepared by condensation of hydrazine with two equivalents of a carbonyl. Azines are also produced when chalcone reacts with a hydrazone to produce 3,5-diphenyl-1''H''-pyrazole, in a conversion also carried out with hydrazine hydrate. : Reactions Azines characteristically undergo hydrolysis to hydrazines. The reaction proceeds by the intermediacy of a hydrazone: :R2C=N-N=CR2 + H2O → R2C=N-NH2 + R2C=O :R2C=N-NH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azine
Azines are a functional class of organic compounds with the connectivity RR'C=N-N=CRR'. These compounds are the product of the condensation of hydrazine with ketones and aldehydes, although in practice they are often made by alternative routes. Ketazines are azines derived from ketones. For example, acetone azine is the simplest ketazine. Aldazines are azines derived from aldehydes. Preparation The usual method of industrial production is the peroxide process, starting from the ketone, ammonia, and hydrogen peroxide. : In the laboratory, azines are typically prepared by condensation of hydrazine with two equivalents of a carbonyl. Azines are also produced when chalcone reacts with a hydrazone to produce 3,5-diphenyl-1''H''-pyrazole, in a conversion also carried out with hydrazine hydrate. : Reactions Azines characteristically undergo hydrolysis to hydrazines. The reaction proceeds by the intermediacy of a hydrazone: :R2C=N-N=CR2 + H2O → R2C=N-NH2 + R2C=O :R2C=N-NH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diazo Compound
The diazo group is an organic moiety consisting of two linked nitrogen atoms ( azo) at the terminal position. Overall charge neutral organic compounds containing the diazo group bound to a carbon atom are called diazo compounds or diazoalkanes and are described by the general structural formula R2C=N+=N–. The simplest example of a diazo compound is diazomethane, CH2N2. Diazo compounds (R2C=N2) should not be confused with azo compounds of the type R-N=N-R or with diazonium compounds of the type R-N2+. Structure The electronic structure of diazo compounds is characterized by π electron density delocalized over the α-carbon and two nitrogen atoms, along with an orthogonal π system with electron density delocalized over only the terminal nitrogen atoms. Because all octet rule-satisfying resonance forms of diazo compounds have formal charges, they are members of a class of compounds known as 1,3-dipoles. Some of the most stable diazo compounds are α-diazo-β-diketones an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arkema
Arkema S.A. is a publicly listed, multi-national manufacturer of specialty materials, headquartered in Colombes, near Paris, France. It has three specialty materials segments (or divisions); adhesives, advanced materials and coatings. A further segment covers chemical intermediates. The company was created in 2004, as part of French oil major Total's restructuring of its chemicals business, and floated on the Paris stock exchange in May 2006. Turnover in 2021 was €9.5 billion. Arkema operates in more than 55 countries and has 20,200 employees, 13 research centers and 144 production plants. History Arkema itself was created when French oil major Total restructured its chemicals business in 2004, but the company's roots go back many years. Origin and evolution In 1971, Elf and Total merged their chemical operations into Aquitaine Total Organico (ATO), a joint subsidiary. The same year saw the creation of Produits Chimiques Ugine Kuhlmann (PCUK). The joint venture was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayer
Bayer AG (, commonly pronounced ; ) is a German multinational corporation, multinational pharmaceutical and biotechnology company and one of the largest pharmaceutical companies in the world. Headquartered in Leverkusen, Bayer's areas of business include pharmaceuticals; consumer healthcare products, agricultural chemicals, seeds and biotechnology products. The company is a component of the Euro Stoxx 50 stock market index. Bayer was founded in 1863 in Barmen as a partnership between dye salesman Friedrich Bayer and dyer Friedrich Weskott. As was common in this era, the company was established as a dyestuffs producer. The versatility of aniline chemistry led Bayer to expand their business into other areas, and in 1899 Bayer launched the compound acetylsalicylic acid under the trademarked name Aspirin. In 1904 Bayer received a trademark for the "Bayer Cross" logo, which was subsequently stamped onto each aspirin tablet, creating an iconic product that is still sold by Bayer. Ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2,4-triazole
1,2,4-Triazole (as ligand in coordination compounds, Htrz abbreviation is sometimes used) is one of a pair of isomeric chemical compounds with molecular formula CHN, called triazoles, which have a five-membered ring of two carbon atoms and three nitrogen atoms. 1,2,4-Triazole and its derivatives find use in a wide variety of applications. Structure and properties 1,2,4-Triazole is a planar molecule. The C-N and N-N distances fall into a narrow range 136 - 132 picometers, consistent with the aromaticity. Although two tautomers can be envisioned, only one exists practically speaking. 1,2,4-Triazole is amphoteric, being susceptible to both N-protonation and deprotonation in aqueous solution. The pKa of 1,2,4-triazolium (C2N3H4+) is 2.45. The pKa of the neutral molecule is 10.26. Synthesis and occurrence 1,2,4-Triazoles can be prepared using the Einhorn–Brunner reaction or the Pellizzari reaction. Unsubstituted 1,2,4-triazole can be prepared from thiosemicarbazide by acylation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbicide
Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page for EPA reports on pesticide use ihere Selective herbicides control specific weed species, while leaving the desired crop relatively unharmed, while non-selective herbicides (sometimes called total weedkillers in commercial products) can be used to clear waste ground, industrial and construction sites, railways and railway embankments as they kill all plant material with which they come into contact. Apart from selective/non-selective, other important distinctions include ''persistence'' (also known as ''residual action'': how long the product stays in place and remains active), ''means of uptake'' (whether it is absorbed by above-ground foliage only, through the roots, or by other means), and ''mechanism of action'' (how it works). Historica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketazine
Azines are a functional class of organic compounds with the connectivity RR'C=N-N=CRR'. These compounds are the product of the condensation of hydrazine with ketones and aldehydes, although in practice they are often made by alternative routes. Ketazines are azines derived from ketones. For example, acetone azine is the simplest ketazine. Aldazines are azines derived from aldehydes. Preparation The usual method of industrial production is the peroxide process, starting from the ketone, ammonia, and hydrogen peroxide. : In the laboratory, azines are typically prepared by condensation of hydrazine with two equivalents of a carbonyl. Azines are also produced when chalcone reacts with a hydrazone to produce 3,5-diphenyl-1''H''-pyrazole, in a conversion also carried out with hydrazine hydrate. : Reactions Azines characteristically undergo hydrolysis to hydrazines. The reaction proceeds by the intermediacy of a hydrazone: :R2C=N-N=CR2 + H2O → R2C=N-NH2 + R2C=O :R2C=N-NH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidant
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 ). 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 a substrate. Combust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analytical Chemistry (journal)
''Analytical Chemistry'' is a biweekly peer-reviewed scientific journal published since 1929 by the American Chemical Society. Articles address general principles of chemical measurement science and novel analytical methodologies. Topics commonly include chemical reactions and selectivity, chemometrics and data processing, electrochemistry, elemental and molecular characterization, imaging, instrumentation, mass spectrometry, microscale and nanoscale systems, -omics, sensing, separations, spectroscopy, and surface analysis. It is abstracted and indexed in Chemical Abstracts Service, CAB International, EBSCOhost, ProQuest, PubMed, Scopus, and the Science Citation Index Expanded. According to the ''Journal Citation Reports'', it has a 2020 impact factor of 6.986 . The editor-in-chief is Jonathan V. Sweedler (University of Illinois). See also * List of chemistry journals References External links * {{DEFAULTSORT:Analytical Chemistry (Journal) Analytical Chemistry Analyti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Chromatography
Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture. In preparative chromatography, GC can be used to prepare pure compounds from a mixture. Gas chromatography is also sometimes known as vapor-phase chromatography (VPC), or gas–liquid partition chromatography (GLPC). These alternative names, as well as their respective abbreviations, are frequently used in scientific literature. Gas chromatography is the process of separating compounds in a mixture by injecting a gaseous or liquid sample into a mobile phase, typically called the carrier gas, and passing the gas through a stationary phase. The mobile phase is usually an inert gas or an unreactive gas such as helium, argon, nitrogen or hydrogen. The stationary phase is a microscopic la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetone
Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscible with water and serves as an important organic solvent in its own right, in industry, home, and laboratory. About 6.7 million tonnes were produced worldwide in 2010, mainly for use as a solvent and production of methyl methacrylate (and from that PMMA) as well as bisphenol A.Acetone World Petrochemicals report, January 2010Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. It is a common building block in |
Ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electron pairs, often through Lewis bases. The nature of metal–ligand bonding can range from covalent to ionic. Furthermore, the metal–ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic "ligands". Metals and metalloids are bound to ligands in almost all circumstances, although gaseous "naked" metal ions can be generated in a high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection requires critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environmental chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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