Dithietanes are saturated heterocyclic compounds that contain two divalent sulfur atoms and two sp3-hybridized carbon centers. [1] [2] Two isomers are possible for this class of organosulfur compounds:
Dithietanes are saturated heterocyclic compounds that contain two divalent sulfur atoms and two sp3-hybridized carbon centers. [1] [2] Two isomers are possible for this class of organosulfur compounds:
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. [3] 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. [4]
In 1,3-dithietanes, the sulfur atoms are non-adjacent. [5] 1,3-Dithietane itself, a colorless, easily sublimed, crystalline, unpleasant-smelling solid with melting point 105-106 °C, was first prepared in 1976 by reaction of bis(chloromethyl) sulfoxide with sodium sulfide followed by THF-borane reduction of the first formed 1,3-dithietane 1-oxide, as shown in the scheme below. [6] [7] Carbon-substituted 1,3-dithietanes are well known, with the first examples being described as early as 1872. Examples include 2,2,4,4-tetrachloro-1,3-dithietane, the photochemically-formed dimer of thiophosgene, and tetrakis(trifluoromethyl)-1,3-dithietane, [(CF3)2CS]2. [8]
Oxidized forms of 1,3-dithietane are well known, although they are often not prepared from the dithietane. Examples include the so-called zwiebelanes (2,3-dimethyl-5,6-dithiabicyclo[2.1.1]hexane S-oxides) from onion volatiles [9] and 1,3-dithietane 1,1,3,3-tetraoxide, the so-called sulfene dimer. [10]
The oxidation state, sometimes referred to as oxidation number, describes the degree of oxidation of an atom in a chemical compound. Conceptually, the oxidation state, which may be positive, negative or zero, is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic, with no covalent component. This is never exactly true for real bonds.
Thiophene is a heterocyclic compound with the formula C4H4S. Consisting of a planar five-membered ring, it is aromatic as indicated by its extensive substitution reactions. It is a colorless liquid with a benzene-like odor. In most of its reactions, it resembles benzene. Compounds analogous to thiophene include furan (C4H4O) selenophene (C4H4Se) and pyrrole (C4H4NH), which each vary by the heteroatom in the ring.
Tetrahedrane is a hypothetical platonic hydrocarbon with chemical formula C4H4 and a tetrahedral structure. The molecule would be subject to considerable angle strain and has not been synthesized as of 2019. However, a number of derivatives have been prepared. In a more general sense, the term tetrahedranes is used to describe a class of molecules and ions with related structure, e.g. white phosphorus.
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 essential for life. Of the 20 common amino acids, two 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.
A transition metal carbene complex is an organometallic compound featuring a divalent organic ligand. The divalent organic ligand coordinated to the metal center is called a carbene. Carbene complexes for almost all transition metals have been reported. Many methods for synthesizing them and reactions utilizing them have been reported. The term carbene ligand is a formalism since many are not derived from carbenes and almost none exhibit the reactivity characteristic of carbenes. Described often as M=CR2, they represent a class of organic ligands intermediate between alkyls (−CR3) and carbynes (≡CR). They feature in some catalytic reactions, especially alkene metathesis, and are of value in the preparation of some fine chemicals.
A sulfone is a chemical compound containing a sulfonyl functional group attached to two carbon atoms. The central hexavalent sulfur atom is double-bonded to each of two oxygen atoms and has a single bond to each of two carbon atoms, usually in two separate hydrocarbon substituents.
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 (C2H4S).
A persistent carbene (also known as stable carbene) is a type of carbene demonstrating particular stability. The best-known examples and by far largest subgroup are the N-heterocyclic carbenes (NHC) (sometimes called Arduengo carbenes), for example diaminocarbenes with the general formula (R2N)2C:, where the 'R's are typically alkyl and aryl groups. The groups can be linked to give heterocyclic carbenes, such as those derived from imidazole, imidazoline, thiazole or triazole.
A halonium ion is any onium ion containing a halogen atom carrying a positive charge. This cation has the general structure R−−R′ where X is any halogen and no restrictions on R, this structure can be cyclic or an open chain molecular structure. Halonium ions formed from fluorine, chlorine, bromine, and iodine are called fluoronium, chloronium, bromonium, and iodonium, respectively. The cyclic variety commonly proposed as intermediates in electrophilic halogenation may be called haliranium ions, using the Hantzsch-Widman nomenclature system.
An alkalide is a chemical compound in which alkali metal atoms are anions with a charge or oxidation state of –1. Until the first discovery of alkalides in the 1970s, alkali metals were only known to appear in salts only as cations with a charge or oxidation state of +1. These types of compounds are of theoretical interest due to their unusual stoichiometry and low ionization potentials. Alkalide compounds are chemically related to the electrides, salts in which trapped electrons are effectively the anions.
A sulfenic acid is an organosulfur compound and oxoacid with the general formula RSOH. It is the first member of the family of organosulfur oxoacids, which also include sulfinic acids and sulfonic acids, RSO2H and RSO3H, respectively. The base member of the sulfenic acid series with R = H is hydrogen thioperoxide.
Dewar benzene (also spelled dewarbenzene) or bicyclo[2.2.0]hexa-2,5-diene is a bicyclic isomer of benzene with the molecular formula C6H6. The compound is named after James Dewar who included this structure in a list of possible C6H6 structures in 1867. However, he did not propose it as the structure of benzene, and in fact he supported the correct structure previously proposed by August Kekulé in 1865.
Dithiete is an unsaturated heterocyclic compound that contains two adjacent sulfur atoms and two sp2-hybridized carbon centers. Derivatives are known collectively as dithietes or 1,2-dithietes. With 6 π electrons, 1,2-dithietes are examples of aromatic organosulfur compounds. A few 1,2-dithietes have been isolated.
The chemical compound 1,2-dioxetanedione, or 1,2-dioxacyclobutane-3,4-dione, often called peroxyacid ester, is an unstable oxide of carbon (an oxocarbon) with formula C2O4. It can be viewed as a double ketone of 1,2-dioxetane (1,2-dioxacyclobutane), or a cyclic dimer of carbon dioxide.
Thiete is a heterocyclic compound containing an unsaturated four-membered ring with three carbon atoms and one sulfur atom. It is more commonly encountered not on its own, but in anellated derivatives, several of which have been synthesized. Thietes are generally not very stable.
In organosulfur chemistry, thiosulfinate is a functional group consisting of the linkage R-S(O)-S-R (R are organic substituents). Thiolsulfinates are also named as alkanethiosulfinic (or arenethiosulfinic) acid esters. They are the first member of a family of compounds containing an oxidized disulfide bond. Other members of this family include thiosulfonates (R-SO2-S-R), α-disulfoxides (R-S(O)-S(O)-R), sulfinyl sulfones (R-S(O)-SO2-R), and α-disulfones (R-SO2-SO2-R), all of which are known. The thiosulfinate group can occur in cyclic as well as acyclic structures.
Carbene analogs in chemistry are carbenes with the carbon atom replaced by another chemical element. Just as regular carbenes they appear in chemical reactions as reactive intermediates and with special precautions they can be stabilized and isolated as chemical compounds. Carbenes have some practical utility in organic synthesis but carbene analogs are mostly laboratory curiosities only investigated in academia. Carbene analogs are known for elements of group 13, group 14, group 15 and group 16.
In chemistry, an oxocarbon anion is a negative ion consisting solely of carbon and oxygen atoms, and therefore having the general formula C
xOn−
y for some integers x, y, and n.
Dimethyl trisulfide (DMTS) is an organic chemical compound and the simplest organic trisulfide. It is a flammable liquid with a foul odor, which is detectable at levels as low as 1 part per trillion.
Sulfinyl halide groups occur when a sulfinyl functional group is singly bonded to a halogen atom. They have the general formula R-S(O)-X, where X is a halogen, and are intermediate in oxidation level between sulfenyl halides, R-S-X, and sulfonyl halides, R-SO2-X. The best known examples are sulfinyl chlorides, thermolabile, moisture-sensitive compounds, which are useful intermediates for preparation of other sufinyl derivatives such as sulfinamides, sulfinates, sulfoxides and thiosulfinates. Unlike the sulfur atom in sulfonyl halides and sulfenyl halides, the sulfur atom in sulfinyl halides is chiral, as shown for methanesulfinyl chloride.