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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 Dach ... [...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 Dach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Diffraction
Electron diffraction refers to the bending of electron beams around atomic structures. This behaviour, typical for waves, is applicable to electrons due to the wave–particle duality stating that electrons behave as both particles and waves. Since the diffracted beams interfere, they generate diffraction patterns widely used for analysis of the objects which caused the diffraction. Therefore, electron diffraction can also refer to derived experimental techniques used for material characterization. This technique is similar to X-ray and neutron diffraction. Electron diffraction is most frequently used in solid state physics and chemistry to study crystalline, quasi-crystalline and amorphous materials using electron microscopes. In these instruments, electrons are accelerated by an electrostatic potential in order to gain energy and shorten their wavelength. With the wavelength sufficiently short, the atomic structure acts as a diffraction grating generating diffraction patte ... [...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 105-10 ... [...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 Dach ... [...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 Carbonate
Ethylene carbonate (sometimes abbreviated EC) is the organic compound with the formula (CH2O)2CO. It is classified as the Cyclic compound, cyclic carbonate ester of ethylene glycol and carbonic acid. At room temperature (25 °C) ethylene carbonate is a transparent crystalline solid, practically odorless and colorless, and somewhat soluble in water. In the liquid state (m.p. 34-37 °C) it is a colorless odorless liquid. JEFFSOL ETHYLENE CARBONATE catalog entry at www.huntsman.com. Accessed on 2010-02-18. Production and reactions Ethylene carbonate is produced by the reaction between ethylene oxide and carbon dioxide. The reaction is catalyzed by a variety of cations and complexes: :(CH2)2O + CO2[...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 Dach ... [...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 as i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiocyanate
Thiocyanate (also known as rhodanide) is the anion . It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Mercury(II) thiocyanate was formerly used in pyrotechnics. Thiocyanate is analogous to the cyanate ion, , wherein oxygen is replaced by sulfur. is one of the pseudohalides, due to the similarity of its reactions to that of halide ions. Thiocyanate used to be known as rhodanide (from a Greek word for rose) because of the red colour of its complexes with iron. Thiocyanate is produced by the reaction of elemental sulfur or thiosulfate with cyanide: : 8 CN- + S8 -> 8 SCN- : CN- + S2O3^2- -> SCN- + SO3^2- The second reaction is catalyzed by thiosulfate sulfurtransferase, a hepatic mitochondrial enzyme, and by other sulfur transferases, which together are responsible for around 80% of cyanide metabolism in the body. Biological chemistry of thiocyanate in medicine Thiocyanate is known to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angstrom
The angstromEntry "angstrom" in the Oxford online dictionary. Retrieved on 2019-03-02 from https://en.oxforddictionaries.com/definition/angstrom.Entry "angstrom" in the Merriam-Webster online dictionary. Retrieved on 2019-03-02 from https://www.merriam-webster.com/dictionary/angstrom. (, ; , ) or ångström is a metric unit of length equal to m; that is, one ten-billionth ( US) of a metre, a hundred-millionth of a centimetre,Entry "angstrom" in the Oxford English Dictionary, 2nd edition (1986). Retrieved on 2021-11-22 from https://www.oed.com/oed2/00008552. 0.1 nanometre, or 100 picometres. Its symbol is Å, a letter of the Swedish alphabet. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–1874). The angstrom is often used in the natural sciences and technology to express sizes of atoms, molecules, microscopic biological structures, and lengths of chemical bonds, arrangement of atoms in crystals,Arturas Vailionis (2015):Geometry of Crystals Lect ... [...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 gives ethylene episulfoxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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