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Tert-butylthiol
''tert''-Butylthiol, also known as ''tert''-butyl mercaptan (TBM), and abbreciated ''t''-BuSH, is an organosulfur compound with the formula (CH3)3CSH. This thiol has a strong odor. It is considered a flavoring agent. Preparation ''tert''-Butylthiol was first prepared in 1890 by Leonard Dobbin by the reaction of zinc sulfide and ''t''-butyl chloride. The compound was later prepared by the reaction of the Grignard reagent, ''t''-BuMgCl, with sulfur to give the corresponding thiolate, followed by hydrolysis. This preparation is shown below: :''t''-BuMgCl + S → ''t''-BuSMgCl :''t''-BuSMgCl + H2O → ''t''-BuSH + Mg(OH)Cl It is made industrially by the reaction of isobutylene with hydrogen sulfide over a clay (silica alumina) catalyst. Reactions ''tert''-Butylthiol is deprotonated by lithium hydride in an aprotic solvent such as hexamethylphosphoramide (HMPA). The resulting lithium thiolate salt has been used as demethylating reagent. For example, treatment with 7-methyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiol
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl group, or a sulfanyl group. Thiols are the sulfur analogue of alcohols (that is, sulfur takes the place of oxygen in the hydroxyl () group of an alcohol), and the word is a blend of "''thio-''" with "alcohol". Many thiols have strong odors resembling that of garlic, cabbage or rotten eggs. Thiols are used as odorants to assist in the detection of natural gas (which in pure form is odorless), and the smell of natural gas is due to the smell of the thiol used as the odorant. Nomenclature Thiols are sometimes referred to as mercaptans () or mercapto compounds, a term introduced in 1832 by William Christopher Zeise and is derived from the Latin ('capturing mercury')''Oxford American Dictionaries'' (Mac OS X Leopard). because the thiolate grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethyl Sulfide
Dimethyl sulfide (DMS) or methylthiomethane is an organosulfur compound with the formula . It is the simplest thioether and has a characteristic disagreeable odor. It is a flammable liquid that boils at . It is a component of the smell produced from cooking of certain vegetables (notably maize, cabbage, and beetroot) and seafoods. It is also an indication of bacterial contamination in malt production and brewing. It is a breakdown product of dimethylsulfoniopropionate (DMSP), and is also produced by the bacterial metabolism of methanethiol. Occurrence and production DMS originates primarily from DMSP, a major secondary metabolite in some marine algae. DMS is the most abundant biological sulfur compound emitted to the atmosphere. Emission occurs over the oceans by phytoplankton. DMS is also produced naturally by bacterial transformation of dimethyl sulfoxide (DMSO) waste that is disposed of into sewers, where it can cause environmental odor problems. DMS is oxidized in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanethiol
Ethanethiol, commonly known as ethyl mercaptan, is an organosulfur compound with the formula CH3CH2SH. It is a colorless liquid with a distinct odor. Abbreviated EtSH, it consists of an ethyl group (Et), CH3CH2, attached to a thiol group, SH. Its structure parallels that of ethanol, but with sulfur in place of oxygen. The odor of EtSH is infamous. Ethanethiol is more volatile than ethanol due to a diminished ability to engage in hydrogen bonding. Ethanethiol is toxic in high concentrations. It occurs naturally as a minor component of petroleum, and may be added to otherwise odorless gaseous products such as liquefied petroleum gas (LPG) to help warn of gas leaks. At these concentrations, ethanethiol is not harmful. Preparation Ethanethiol is prepared by the reaction of ethylene with hydrogen sulfide in the presence of various catalysts. It is also prepared commercially by the reaction of ethanol with hydrogen sulfide gas over an acidic solid catalyst, such as alumina. Historic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butanethiol
Butane-1-thiol, also known as butyl mercaptan, is an organosulfur compound with the formula . It is classified as a thiol. It is a volatile, colorless liquid with a fetid (extremely foul-smelling) odor, commonly described as "skunk" odor. In fact, 1-butanethiol is structurally similar to several constituents of a skunk's defensive spray but is not present in the spray. The scent of 1-butanethiol is so strong that the human nose can easily detect it in the air at concentrations as low as 10 parts per billion. The threshold level for 1-butanethiol is reported as 1.4 ppb Uses Butane-1-thiol is used as an industrial solvent, and as an intermediate for cotton defoliants. It is sometimes placed in "stink bomb A stink bomb, sometimes called a stinkpot, is a device designed to create an unpleasant smell. They range in effectiveness from being used as simple pranks to military grade malodorants or riot control chemical agents. History A stink bomb ...s" and "stink perfumes" for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Food Safety Authority
The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain. EFSA was established in February 2002 in Parma, Italy. It had a yearly budget of €118.6 million, and a total staff of 542 as of 2021. The work of EFSA covers all matters with a direct or indirect impact on food and feed safety, including animal health and welfare, plant protection and plant health and nutrition. EFSA supports the European Commission, the European Parliament and EU member states in taking effective and timely risk management decisions that ensure the protection of the health of European consumers and the safety of the food and feed chain. EFSA also communicates to the public in an open and transparent way on all matters within its remit. Structure Based on a regulation of 2002, the EFSA is composed of four bodies: * Management Board * Executive Direc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butanethiol
Butane-1-thiol, also known as butyl mercaptan, is an organosulfur compound with the formula . It is classified as a thiol. It is a volatile, colorless liquid with a fetid (extremely foul-smelling) odor, commonly described as "skunk" odor. In fact, 1-butanethiol is structurally similar to several constituents of a skunk's defensive spray but is not present in the spray. The scent of 1-butanethiol is so strong that the human nose can easily detect it in the air at concentrations as low as 10 parts per billion. The threshold level for 1-butanethiol is reported as 1.4 ppb Uses Butane-1-thiol is used as an industrial solvent, and as an intermediate for cotton defoliants. It is sometimes placed in "stink bomb A stink bomb, sometimes called a stinkpot, is a device designed to create an unpleasant smell. They range in effectiveness from being used as simple pranks to military grade malodorants or riot control chemical agents. History A stink bomb ...s" and "stink perfumes" for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sec-Butyl Mercaptan
In organic chemistry, butyl is a four-carbon alkyl radical or substituent group with general chemical formula , derived from either of the two isomers (''n''-butane and isobutane) of butane. The isomer ''n''-butane can connect in two ways, giving rise to two "-butyl" groups: * If it connects at one of the two terminal carbon atoms, it is normal butyl or ''n''-butyl: (preferred IUPAC name: butyl) * If it connects at one of the non-terminal (internal) carbon atoms, it is secondary butyl or ''sec''-butyl: (preferred IUPAC name: butan-2-yl) The second isomer of butane, isobutane, can also connect in two ways, giving rise to two additional groups: * If it connects at one of the three terminal carbons, it is isobutyl: (preferred IUPAC name: 2-methylpropyl) * If it connects at the central carbon, it is tertiary butyl, ''tert''-butyl or ''t''-butyl: (preferred IUPAC name: ''tert''-butyl) Nomenclature According to IUPAC nomenclature, "isobutyl", "''sec''-butyl", and "''tert''-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isopropyl Mercaptan
Isopropyl mercaptan is a thiol with the formula C3H8S. It is a water-white liquid with an extremely pungent odor resembling skunk spray or rotten eggs. The pungent smell allows it to be used as an odorizer. The FDA has approved it for use as a food additive Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ... for its flavor. Another use is as a rubber additive.{{Cite journal , last1=Li , first1=Zhiwei , last2=An , first2=Dong , last3=He , first3=Rizheng , last4=Sun , first4=Zhijian , last5=Li , first5=Jiaxiong , last6=Zhang , first6=Zhiyi , last7=Liu , first7=Yaqing , last8=Wong , first8=Chingping , date=April 2023 , title=The design of crosslinks in different vulcanized systems to improve crack growth resistance for carbon black/graphene oxide/natural rubber composites , url=https:// ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahydrothiophene
Tetrahydrothiophene is an organosulfur compound with the formula (CH2)4S. The molecule consists of a five-membered saturated ring with four methylene groups and a sulfur atom. It is the saturated analog of thiophene and is therefore the sulfur analog of THF. It is a volatile, colorless liquid with an intensely unpleasant odor. It is also known as thiophane, thiolane, or THT. Synthesis and reactions Tetrahydrothiophene is prepared by the reaction of tetrahydrofuran with hydrogen sulfide. This vapor-phase reaction is catalyzed by alumina and other heterogenous acid catalysts. This compound is a ligand in coordination chemistry, an example being the complex chloro(tetrahydrothiophene)gold(I). Oxidation of THT gives the sulfone sulfolane, which is of interest as a polar, odorless solvent: : Sulfolane is, however, more conventionally prepared from butadiene. Natural occurrence Both unsubstituted and substituted tetrahydrothiophenes are reported to occur in nature. For examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Ethyl Sulfide
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula (whereas normal methane has the formula ). In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many organic compounds. It is a very stable group in most molecules. While the methyl group is usually part of a larger molecule, bonded to the rest of the molecule by a single covalent bond (), it can be found on its own in any of three forms: methanide anion (), methylium cation () or methyl radical (). The anion has eight valence electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed. Methyl cation, anion, and radical Methyl cation The methylium cation () exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the cation, and this simplification is used pervasively in organic chemistry. For exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
