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Sultine
In chemistry, a sultine is a cyclic ester of a sulfinic acid. This class of organosulfur compounds has few applications. These compounds are typically prepared by the dehydration of hydroxy-sulfinic acids or their equivalent. Illustrative of an alternative route, xylylene dibromide reacts with sodium sulfoxylate (source of SO22-) to give the sultine C6H4(CH2S(O)OCH2), which is a precursor to o-quinodimethane In organic chemistry, a xylylene (sometimes quinone-dimethide) is any of the constitutional isomers having the formula C6H4(CH2)2. These compounds are related to the corresponding quinones and quinone methides by replacement of the oxygen atoms ....{{cite book, first1=Donald C., last1=Dittmer, first2=Michael D., last2=Hoey , chapter=Cyclic Sulphinic Acid Derivatives (Sultines and Sulphinamides), page = 239-273, year=1981, editor=Saul Patai, title=Sulphinic Acids, Esters and Derivatives, doi=10.1002/9780470772270.ch9, publisher=John Wiley & Sons, series=PATAI'S Chemistr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfinic Acid
Sulfinic acids are oxoacids of sulfur with the structure RSO(OH). In these organosulfur compounds, sulfur is pyramidal. Structure and properties Sulfinic acids RSO2H are about 1000x more acidic than the corresponding carboxylic acid RCO2H. Sulfur is pyramidal, consequently sulfinic acids are chiral. Preparation They are often prepared in situ by acidification of the corresponding sulfinate salts, which are typically more robust than the acid. These salts are generated by reduction of sulfonyl chlorides. An alternative route is the reaction of Grignard reagents with sulfur dioxide. Transition metal sulfinates are also generated by insertion of sulfur dioxide into metal alkyls, a reaction that may proceed via a metal sulfur dioxide complex. Unsubstituted sulfinic acid, when R is the hydrogen atom, is a higher energy isomer of sulfoxylic acid, both of which are unstable. Examples An example of a simple, well-studied sulfinic acid is phenylsulfinic acid. A commercially import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfinic Acids
Sulfinic acids are oxoacids of sulfur with the structure RSO(OH). In these organosulfur compounds, sulfur is pyramidal. Structure and properties Sulfinic acids RSO2H are about 1000x more acidic than the corresponding carboxylic acid RCO2H. Sulfur is pyramidal, consequently sulfinic acids are chiral. Preparation They are often prepared in situ by acidification of the corresponding sulfinate salts, which are typically more robust than the acid. These salts are generated by reduction of sulfonyl chlorides. An alternative route is the reaction of Grignard reagents with sulfur dioxide. Transition metal sulfinates are also generated by insertion of sulfur dioxide into metal alkyls, a reaction that may proceed via a metal sulfur dioxide complex. Unsubstituted sulfinic acid, when R is the hydrogen atom, is a higher energy isomer of sulfoxylic acid, both of which are unstable. Examples An example of a simple, well-studied sulfinic acid is phenylsulfinic acid. A commercially importa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a Chemical reaction, reaction with other Chemical substance, substances. Chemistry also addresses the nature of chemical bonds in chemical compounds. In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both Basic research, basic and Applied science, applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant growth (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the properties ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organosulfur Compound
Organosulfur compounds are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulfur is vital for life. Of the 20 common amino acids, two ( cysteine and methionine) are organosulfur compounds, and the antibiotics penicillin and sulfa drugs both contain sulfur. While sulfur-containing antibiotics save many lives, sulfur mustard is a deadly chemical warfare agent. Fossil fuels, coal, petroleum, and natural gas, which are derived from ancient organisms, necessarily contain organosulfur compounds, the removal of which is a major focus of oil refineries. Sulfur shares the chalcogen group with oxygen, selenium, and tellurium, and it is expected that organosulfur compounds have similarities with carbon–oxygen, carbon–selenium, and carbon–tellurium compounds. A classical chemical test for the detection of sulfur co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylylene Dibromide
Xylylene dibromide is an organic compound with the formula C6H4(CH2Br)2. It is an off-white solid that, like other benzyl halides, a strong lachrymator. It is a useful reagent owing to the convenient reactivity of the two C-Br bonds. Two other isomers are known, para- and meta-xylylene dibromide. Synthesis It is prepared by the photochemical reaction of ortho-xylene with bromine: :C6H4(CH3)2 + 2Br2 → C6H4(CH2Br)2 + 2 HBr Reactions Further bromination gives the tetrabromide: :C6H4(CH2Br)2 + 2Br2 → C6H4(CHBr2)2 + 2 HBr Upon reaction with thiourea followed by hydrolysis of the intermediate bisisothiouronium salts, xylylene dibromide can be converted to the dithiol C6H4(CH2SH)2. Xylylene dibromide is a precursor to the ephemeral molecule ortho-quinonedimethane, also known as xylylene. This species can be trapped when the dehalogenation is conducted in the presence of iron carbonyl. Coupling of xylylene dibromide by treatment with lithium metal gives dibenzo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Sulfoxylate
Sodium dithionite (also known as sodium hydrosulfite) is a white crystalline powder with a sulfurous odor. Although it is stable in dry air, it decomposes in hot water and in acid solutions. Structure The structure has been examined by Raman spectroscopy and single-crystal X-ray diffraction. The dithionite dianion has C symmetry, with almost eclipsed with a 16° O-S-S-O torsional angle. In the dihydrated form (), the dithionite anion has gauche 56° O-S-S-O torsional angle. A weak S-S bond is indicated by the S-S distance of 239 pm, which is elongated by ca. 30 pm relative to a typical S-S bond. Because this bond is fragile, the dithionite anion dissociates in solution into the O2sup>− radicals, as has been confirmed by EPR spectroscopy. It is also observed that 35S undergoes rapid exchange between S2O42− and SO2 in neutral or acidic solution, consistent with the weak S-S bond in the anion. Preparation Sodium dithionite is produced industrially by reduction of sulfur d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinodimethane
In organic chemistry, a xylylene (sometimes quinone-dimethide) is any of the constitutional isomers having the formula C6H4(CH2)2. These compounds are related to the corresponding quinones and quinone methides by replacement of the oxygen atoms by CH2 groups. ''ortho''- and ''para''-xylylene are best known, although neither is stable in solid or liquid form. The ''meta'' form is a diradical. Certain substituted derivatives of xylylenes are however highly stable, such as tetracyanoquinodimethane and the xylylene dichlorides. p-Xylylene ''p''-Xylylene forms upon pyrolysis of ''p''-xylene or, more readily, the α-substituted derivatives. ''p''-Xylylene dimerizes with moderate efficiency to give ''p''-cyclophane: Further heating of the ''p''-cyclophane gives poly(''para''-xylylene). o-Xylylenes o-Xylylenes (''o''-quinodimethanes) are often generated in situ, e.g., by the pyrolysis of the corresponding sulfone. Another method involves 1,4-elimination of ortho benzylic silanes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Groups
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis. A functional group is a group of atoms in a molecule with distinctive chemical properties, regardless of the other atoms in the molecule. The atoms in a functional group are linked to each other and to the rest of the molecule by covalent bonds. For repeating units of polymers, functional groups attach to their nonpolar core of carbon atoms and thus add chemical character to carbon chains. Functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
