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Episulfide
In organic chemistry, episulfides are a class of organic compounds that contain a saturated, heterocyclic ring consisting of two carbon atoms and one sulfur atom. It is the sulfur analogue of an epoxide or aziridine. They are also known as thiiranes, olefin sulfides, thioalkylene oxides, and thiacyclopropanes. Episulfides are less common and generally less stable than epoxides. The most common derivative is ethylene sulfide (). Structure According to electron diffraction, the and distances in ethylene sulfide are respectively 1.473 and 1.811 Å. The and angles are respectively 66.0 and 48.0°. Preparation History A number of chemists in the early 1900s, including Staudinger and Pfenninger (1916), as well as Delepine (1920) studied episulfides.Sander, M. Thiiranes. Chem. Rev. 1966, 66(3), 297-339. I 1934 Dachlauer and Jackel devised a general synthesis of episulfides from epoxides using alkali thiocyanates and thiourea. Contemporary methods Following the lead of Da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Episulfide
In organic chemistry, episulfides are a class of organic compounds that contain a saturated, heterocyclic ring consisting of two carbon atoms and one sulfur atom. It is the sulfur analogue of an epoxide or aziridine. They are also known as thiiranes, olefin sulfides, thioalkylene oxides, and thiacyclopropanes. Episulfides are less common and generally less stable than epoxides. The most common derivative is ethylene sulfide (). Structure According to electron diffraction, the and distances in ethylene sulfide are respectively 1.473 and 1.811 Å. The and angles are respectively 66.0 and 48.0°. Preparation History A number of chemists in the early 1900s, including Staudinger and Pfenninger (1916), as well as Delepine (1920) studied episulfides.Sander, M. Thiiranes. Chem. Rev. 1966, 66(3), 297-339. I 1934 Dachlauer and Jackel devised a general synthesis of episulfides from epoxides using alkali thiocyanates and thiourea. Contemporary methods Following the lead of Da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Episulfide Pic4
In organic chemistry, episulfides are a class of organic compounds that contain a saturated, heterocyclic ring consisting of two carbon atoms and one sulfur atom. It is the sulfur analogue of an epoxide or aziridine. They are also known as thiiranes, olefin sulfides, thioalkylene oxides, and thiacyclopropanes. Episulfides are less common and generally less stable than epoxides. The most common derivative is ethylene sulfide (). Structure According to electron diffraction, the and distances in ethylene sulfide are respectively 1.473 and 1.811 Å. The and angles are respectively 66.0 and 48.0°. Preparation History A number of chemists in the early 1900s, including Staudinger and Pfenninger (1916), as well as Delepine (1920) studied episulfides.Sander, M. Thiiranes. Chem. Rev. 1966, 66(3), 297-339. I 1934 Dachlauer and Jackel devised a general synthesis of episulfides from epoxides using alkali thiocyanates and thiourea. Contemporary methods Following the lead of Da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Episulfide Pic2
In organic chemistry, episulfides are a class of organic compounds that contain a saturated, heterocyclic ring consisting of two carbon atoms and one sulfur atom. It is the sulfur analogue of an epoxide or aziridine. They are also known as thiiranes, olefin sulfides, thioalkylene oxides, and thiacyclopropanes. Episulfides are less common and generally less stable than epoxides. The most common derivative is ethylene sulfide (). Structure According to electron diffraction, the and distances in ethylene sulfide are respectively 1.473 and 1.811 Å. The and angles are respectively 66.0 and 48.0°. Preparation History A number of chemists in the early 1900s, including Staudinger and Pfenninger (1916), as well as Delepine (1920) studied episulfides.Sander, M. Thiiranes. Chem. Rev. 1966, 66(3), 297-339. I 1934 Dachlauer and Jackel devised a general synthesis of episulfides from epoxides using alkali thiocyanates and thiourea. Contemporary methods Following the lead of Da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxide
In organic chemistry, an epoxide is a cyclic ether () with a three-atom ring. This ring approximates an equilateral triangle, which makes it strained, and hence 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'', but such materials do not contain epoxide groups (or contain only a few residual epoxy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Thiocyanate
Potassium thiocyanate is the chemical compound with the molecular formula KSCN. It is an important salt of the thiocyanate anion, one of the pseudohalides. The compound has a low melting point relative to most other inorganic salts. Use in chemical synthesis Aqueous KSCN reacts almost quantitatively with Pb(NO3)2 to give Pb(SCN)2, which has been used to convert acyl chlorides to isothiocyanates. KSCN converts ethylene carbonate to ethylenesulfide. For this purpose, the KSCN is first melted under vacuum to remove water. In a related reaction, KSCN converts cyclohexene oxide to the corresponding episulfide. :C6H10O + KSCN → C6H10S + KOCN KSCN is also the starting product for the synthesis of carbonyl sulfide. Other uses Dilute aqueous KSCN is occasionally used for moderately realistic blood effects in film and theater. It can be painted onto a surface or kept as a colorless solution. When in contact with ferric chloride solution (or other solutions containing Fe3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethylene Sulfide
Thiirane, more commonly known as ethylene sulfide, is the cyclic chemical compound with the formula C2H4S. It is the smallest sulfur-containing heterocycle and the simplest episulfide. Like many organosulfur compounds, this species has a highly unpleasant odour. Thiirane is also used to describe any derivative of the parent ethylene sulfide. Structure According to electron diffraction, the C-C and C-S distances in ethylene sulfide are respectively 1.473 and 1.811 Å. The C-C-S and C-S-C angles are respectively 66.0 and 48.0°. Preparation and reactions It can be prepared by the reaction of ethylene carbonate and KSCN. For this purpose the KSCN is first melted under vacuum to remove water. :KSCN + C2H4O2CO → KOCN + C2H4S + CO2 Ethylenesulfide adds to amines to afford 2-mercaptoethylamines, which are good chelating ligands. :C2H4S + R2NH → R2NCH2CH2SH This process is often called mercaptoethylation. Oxidation of thiirane with periodate Periodate is an anion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocycle
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone, which means "burning stone". Today, almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.. Downloahere The greatest commercial use of the element is the production ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiourea
Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), except that the oxygen atom is replaced by a sulfur atom (as implied by the ''thio-'' prefix); however, the properties of urea and thiourea differ significantly. Thiourea is a reagent in organic synthesis. " Thioureas" refer to a broad class of compounds with the general structure . Thioureas are related to thioamides, e.g. , where R is methyl, ethyl, etc. Structure and bonding Thiourea is a planar molecule. The C=S bond distance is 1.71 Å. The C-N distances average 1.33 Å. The weakening of the C-S bond by C-N pi-bonding is indicated by the short C=S bond in thiobenzophenone, which is 1.63 Å. Thiourea occurs in two tautomeric forms, of which the thione form predominates in aqueous solutions. The equilibrium constant has been calculated as ''K''eq is . The thiol form, which is also known as an isothiourea, can be encountered in substituted compounds such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dithietane
Dithietanes are saturated heterocyclic compounds that contain two divalent sulfur atoms and two sp3-hybridized carbon centers. Two isomers are possible for this class of organosulfur compounds: 1,2-Dithietanes 1,2-dithietanes, 4-membered rings where the two sulfur atoms are adjacent, are very rare. The first stable 1,2-dithietane to be reported was the so-called dithiatopazine formed by intramolecular photodimerization of a dithiocarbonyl compound. 1,2-Dithietanes are to be distinguished from 1,2- dithietes, containing two adjacent sulfur atoms and two sp2-hybridized carbon centers. A stable 1,2-dithietane ''derivative'' is ''trans''-3,4-diethyl-1,2-dithietane 1,1-dioxide, formed by the spontaneous dimerization of the lachrymatory agent syn-propanethial-S-oxide, found in onion. 1,3-Dithietanes In 1,3-dithietanes, the sulfur atoms are non-adjacent. 1,3-Dithietane itself, a colorless, easily sublimed, crystalline, unpleasant-smelling solid with melting point 105-106&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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