A thiosulfoxide or thiothionyl compound is a chemical compound containing a sulfur to sulfur double bond, with the formula (R−)(R'−)S=S, where R and R' represent any group (typically fluorine, chlorine, alkoxy, alkyl, aryl or other organyl residues. The thiosulfoxide has a molecular shape known as trigonal pyramidal. Its coordination is also trigonal pyramidal. The point group of the thiosulfoxide is Cs. A 1982 review concluded that there was as yet no definitive evidence for the existence of stable thiosulfoxides [1] which can be attributed to the double bond rule which states that elements of period 3 and beyond do not form multiple bonds. The related sulfoxides of the type (R−)(R'−)S=O are very common. Many compounds containing a sulfur-sulfur double bond have been reported in the past although only a few verified classes of actually stable compounds exist, closely related to thiosulfoxides.
Sulfur-sulfur double bonds can be stabilized with electron-withdrawing groups in so-called thionosulfites of the type (R−O−)(R'−O−)S=S. These compounds can be prepared by reaction of diols with disulfur dichloride. Sulfur halides such as disulfur dichloride, Cl−S−S−Cl, can convert to the branched isomer thiothionyl chloride, Cl2S=S; disulfur difluoride exists as an equilibrium mixture with thiothionyl fluoride, F2S=S, which is thermodynamically more stable. These disulfide isomerizations are occasionally studied in silico . [2]
N-(Thiosulfinyl)amines of the type R−N=S=S are another group of stable compounds containing a S=S bond. The first such compound was prepared in 1974 reaction of the nitroso compound N,N-dimethyl-p-nitrosoaniline with tetraphosphorus decasulfide. Heating to 200 °C extrudes sulfur in this compound and forms the corresponding azo compound. Disulfur monoxide S=S=O is stable at 20 °C for several days.
Occasionally thiosulfates are depicted as having a S=S unit but the sulfur-sulfur bond in it is in fact a single bond.
In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or in the terminal position. Terminal alkenes are also known as α-olefins.
A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents. Many metal-containing compounds, especially those that include transition metals, are coordination complexes.
In chemistry, a hypervalent molecule is a molecule that contains one or more main group elements apparently bearing more than eight electrons in their valence shells. Phosphorus pentachloride, sulfur hexafluoride, chlorine trifluoride, the chlorite ion, and the triiodide ion are examples of hypervalent molecules.
Valence shell electron pair repulsion (VSEPR) theory, is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm theory after its two main developers, Ronald Gillespie and Ronald Nyholm.
Organotin chemistry is the scientific study of the synthesis and properties of organotin compounds or stannanes, which are organometallic compounds containing tin carbon bonds. The first organotin compound was diethyltin diiodide, discovered by Edward Frankland in 1849. The area grew rapidly in the 1900s, especially after the discovery of the Grignard reagents, which are useful for producing Sn–C bonds. The area remains rich with many applications in industry and continuing activity in the research laboratory.
Organosulfur chemistry is the study of the properties and synthesis of organosulfur compounds, which 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 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.
Diphosphene is a type of organophosphorus compound that has a phosphorus–phosphorus double bond, denoted by R-P=P-R'. These compounds are not common but are of theoretical interest. Normally, compounds with the empirical formula RP exist as rings. However, like other multiple bonds between heavy main-group elements, P=P double bonds can be stabilized by a large steric hindrance from the substitutions. The first isolated diphosphene bis(2,4,6-tri-tert-butylphenyl)diphosphene was exemplified by Masaaki Yoshifuji and his coworkers in 1981, in which diphosphene is stabilized by two bulky phenyl group.
In organic chemistry, a sulfoxide, also called a sulfoxide, is an organosulfur compound containing a sulfinyl functional group attached to two carbon atoms. It is a polar functional group. Sulfoxides are oxidized derivatives of sulfides. Examples of important sulfoxides are alliin, a precursor to the compound that gives freshly crushed garlic its aroma, and dimethyl sulfoxide (DMSO), a common solvent.
In coordination chemistry, metal ammine complexes are metal complexes containing at least one ammonia ligand. "Ammine" is spelled this way due to historical reasons; in contrast, alkyl or aryl bearing ligands are spelt with a single "m". Almost all metal ions bind ammonia as a ligand, but the most prevalent examples of ammine complexes are for Cr(III), Co(III), Ni(II), Cu(II) as well as several platinum group metals.
Tetrasulfur tetranitride is an inorganic compound with the formula S4N4. This gold-poppy coloured solid is the most important binary sulfur nitride, which are compounds that contain only the elements sulfur and nitrogen. It is a precursor to many S-N compounds and has attracted wide interest for its unusual structure and bonding.
Organosilicon chemistry is the study of organometallic compounds containing carbon–silicon bonds, to which they are called organosilicon compounds. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, flammable, hydrophobic, and stable to air. Silicon carbide is an inorganic compound.
Disulfur dichloride is the inorganic compound of sulfur and chlorine with the formula S2Cl2. It is an amber oily liquid.
Selenium tetrafluoride (SeF4) is an inorganic compound. It is a colourless liquid that reacts readily with water. It can be used as a fluorinating reagent in organic syntheses (fluorination of alcohols, carboxylic acids or carbonyl compounds) and has advantages over sulfur tetrafluoride in that milder conditions can be employed and it is a liquid rather than a gas.
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 1869. 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.
In chemistry, a sulfilimine is a type of chemical compound containing a sulfur-to-nitrogen bond which is often represented as a double bond. In fact, a double bond violates the octet rule, and the bond may be considered a single bond with a formal charge of +1 on the sulfur and a formal charge of −1 on the nitrogen. The parent compound is sulfilimine H2S=NH, which is mainly of theoretical interest.
Sulfur chloride pentafluoride is an inorganic compound with the formula SF5Cl. It exists as a colorless gas at room temperature and is highly toxic, like most inorganic compounds containing the pentafluorosulfide functional group. The compound adopts an octahedral geometry with C
4v symmetry. Sulfur chloride pentafluoride is the only commercially available reagent for adding the –SF5 group to organic compounds.
In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula AOmXn, where X is a halogen. Known oxohalides have fluorine (F), chlorine (Cl), bromine (Br), and/or iodine (I) in their molecules. The element A may be a main group element, a transition element, a rare earth element or an actinide. The term oxohalide, or oxyhalide, may also refer to minerals and other crystalline substances with the same overall chemical formula, but having an ionic structure.
Thiosulfurous acid (HS−S(=O)−OH) is a hypothetical chemical compound with the formula S2(OH)2. Attempted synthesis leads to polymers. It is a low oxidation state (+1) sulfur acid. It is the equivalent acid for disulfur monoxide. Salts derived from thiosulfurous acid, which are also unknown, are named "thiosulfites" or "sulfurothioites". The ion is S=SO2−
2.
Sulfur diimides are chemical compounds of the formula S(NR)2. Structurally, they are the diimine of sulfur dioxide. The parent member, S(NH)2, is of only theoretical interest. Other derivatives where R is an organic group are stable and useful reagents.
Disulfur diiodide is an unstable inorganic chemical compound with the chemical formula S2I2. Its empirical formula is SI. It is a red-brown solid that decomposes above −30 °C to elemental sulfur and iodine.