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Dimethyldisulfide
Dimethyl disulfide (DMDS) is an organic chemical compound with the molecular formula which is the simplest disulfide. It is a flammable liquid with an unpleasant, garlic-like odor. Occurrence Dimethyl disulfide is a widespread natural odoriferous compound emitted from many sources such as bacteria, fungi, plants and animals. It is an oxidation product of methanethiol in air. Along with dimethyl sulfide and dimethyl trisulfide it has been confirmed as volatile compounds given off by the fly-attracting plant known as dead-horse arum ('' Helicodiceros muscivorus''). These flies are attracted to the odor resembling that of fetid meat, and thus help pollinate this plant. DMDS can be produced by the oxidation of methanethiol, e.g. with iodine: : Chemical reactions Important reactions include chlorination giving methanesulfenyl chloride (), methanesulfinyl chloride (), and methanesulfonyl chloride () as well as oxidation with hydrogen peroxide or peracetic acid giving the thio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 34,000 in the UK and a further 8,000 abroad. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing and Shanghai, China and in Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine
Iodine is a chemical element with the Symbol (chemistry), symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a violet gas at . The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek 'violet-coloured'. Iodine occurs in many oxidation states, including iodide (I−), iodate (), and the various periodate anions. It is the least abundant of the stable halogens, being the sixty-first most abundant element. As the heaviest essential mineral nutrient, iodine is required for the synthesis of thyroid hormones. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities. The dominant producers of iodine today are Chile and Japan. Due to its high atomic number and ease of attachment to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiophene
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. Isolation and occurrence Thiophene was discovered as a contaminant in benzene. It was observed that isatin (an indole) forms a blue dye if it is mixed with sulfuric acid and crude benzene. The formation of the blue indophenin had long been believed to be a reaction of benzene itself. Viktor Meyer was able to isolate thiophene as the actual substance responsible for this reaction. Thiophene and especially its derivatives occur in petroleum, sometimes in concentrations up to 1–3%. The thiophenic content of oil and coal is removed via the hydrodesulfurization ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arkema
Arkema S.A. is a publicly listed, multi-national manufacturer of specialty materials, headquartered in Colombes, near Paris, France. It has three specialty materials segments (or divisions); adhesives, advanced materials and coatings. A further segment covers chemical intermediates. The company was created in 2004, as part of French oil major Total's restructuring of its chemicals business, and floated on the Paris stock exchange in May 2006. Turnover in 2021 was €9.5 billion. Arkema operates in more than 55 countries and has 20,200 employees, 13 research centers and 144 production plants. History Arkema itself was created when French oil major Total restructured its chemicals business in 2004, but the company's roots go back many years. Origin and evolution In 1971, Elf and Total merged their chemical operations into Aquitaine Total Organico (ATO), a joint subsidiary. The same year saw the creation of Produits Chimiques Ugine Kuhlmann (PCUK). The joint venture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Bromide
Bromomethane, commonly known as methyl bromide, is an organobromine compound with formula C H3 Br. This colorless, odorless, nonflammable gas is produced both industrially and biologically. It has a tetrahedral shape and it is a recognized ozone-depleting chemical. It was used extensively as a pesticide until being phased out by most countries in the early 2000s. Occurrence and manufacture Bromomethane originates from both natural and human sources. In the ocean, marine organisms are estimated to produce 56,000 tonnes annually. It is also produced in small quantities by certain terrestrial plants, such as members of the family Brassicaceae. It is manufactured for agricultural and industrial use by treating methanol with bromine in the presence of sulfur or hydrogen sulfide: :6 CH3OH + 3 Br2 + S → 6 CH3Br + 2 H2O + H2SO4 Uses In 1999, an estimated 71,500 tonnes of synthetic methyl bromide were used annually worldwide. 97% of this estimate was used for fumigation purposes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiosulfinate
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. Occurrence A variety of acyclic and cyclic thiosulfinates are found in plants, or formed when the plants are cut or crushed. A well-known thiosulfinate is allicin, one of the active ingredients formed when garlic is crushed. Allicin was discovered in 1944 by Chester J. Cavallito and coworkers. Thiosulfinates containing various combinations of the methyl, ''n''-propyl, 1-propenyl, 2-propenyl, ''n''-butyl, 1-buten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peracetic Acid
Peracetic acid (also known as peroxyacetic acid, or PAA) is an organic compound with the chemical formula, formula CH3CO3H. This peroxy acid is a colorless liquid with a characteristic acrid odor reminiscent of acetic acid. It can be highly corrosive. Peracetic acid is a weaker acid than the parent acetic acid, with a Acid dissociation constant, p''K''a of 8.2. Production Peracetic acid is produced industrially by the autoxidation of acetaldehyde: :O2 + CH3CHO → CH3CO3H It forms upon treatment of acetic acid with hydrogen peroxide with a strong acid catalyst: :H2O2 + CH3CO2H CH3CO3H + H2O As an alternative, acetyl chloride and acetic anhydride can be used to generate a solution of the acid with lower water content. Peracetic acid is generated ''in situ'' by some laundry detergents. This is achieved by the action of bleach activators, such as tetraacetylethylenediamine and sodium nonanoyloxybenzenesulfonate, upon hydrogen peroxide formed from sodium percarbonate in water. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%–6% by weight) in water for consumer use, and in higher concentrations for industrial use. Concentrated hydrogen peroxide, or " high-test peroxide", decomposes explosively when heated and has been used as a propellant in rocketry. Hydrogen peroxide is a reactive oxygen species and the simplest peroxide, a compound having an oxygen–oxygen single bond. It decomposes slowly when exposed to light, and rapidly in the presence of organic or reactive compounds. It is typically stored with a stabilizer in a weakly acidic solution in a dark bottle to block light. Hydrogen peroxide is found in biological systems including the human body. Enzymes that use or decompose hydrogen peroxide are classified as peroxidases. Properties The boiling p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanesulfonyl Chloride
Methanesulfonyl chloride (mesyl chloride) is an organosulfur compound with the formula . Using the organic pseudoelement symbol Ms for the methanesulfonyl (or mesyl) group –, it is frequently abbreviated MsCl in reaction schemes or equations. It is a colourless liquid that dissolves in polar organic solvents but is reactive toward water, alcohols, and many amines. The simplest organic sulfonyl chloride, it is used to make methanesulfonates and to generate the elusive molecule sulfene (methylenedioxosulfur(VI)).Valerie Vaillancourt, Michele M. Cudahy, Matthew M. Kreilein and Danielle L. Jacobs "Methanesulfonyl Chloride" in E-EROS Encyclopedia for Reagents in Organic Synthesis. Preparation It is manufactured by the reaction of methane and sulfuryl chloride in a radical reaction: : Another method of manufacture entails chlorination of methanesulfonic acid with thionyl chloride or phosgene: : : Reactions Methanesulfonyl chloride is a precursor to many compounds because it is h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanethiol
Methanethiol (also known as methyl mercaptan) is an organosulfur compound with the chemical formula . It is a colorless gas with a distinctive putrid smell. It is a natural substance found in the blood, brain and feces of animals (including humans), as well as in plant tissues. It also occurs naturally in certain foods, such as some nuts and cheese. It is one of the chemical compounds responsible for bad breath and the smell of flatus. Methanethiol is the simplest thiol and is sometimes abbreviated as MeSH. It is very flammable. Structure and reactions The molecule is tetrahedral at the carbon atom, like methanol. It is a weak acid, with a p''K''a of ~10.4, but is about a hundred thousand times more acidic than methanol. The colorless salt can be obtained in this way: :CH3SH + CH3ONa → CH3SNa + CH3OH The resulting thiolate anion is a strong nucleophile. It can be oxidized to dimethyl disulfide: :2CH3SH + → CH3SSCH3 + H2O Further oxidation takes the disulfide to two mol ... [...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] |
Odor
An odor (American English) or odour (Commonwealth English; see spelling differences) is caused by one or more volatilized chemical compounds that are generally found in low concentrations that humans and animals can perceive via their sense of smell. An odor is also called a "smell" or a "scent", which can refer to either a pleasant or an unpleasant odor. While "odor" and "smell" can refer to pleasant and unpleasant odors, the terms "scent", "aroma", and "fragrance" are usually reserved for pleasant-smelling odors and are frequently used in the food and cosmetic industry to describe floral scents or to refer to perfumes. Physiology of smell Sense of smell The perception of odors, or sense of smell, is mediated by the olfactory nerve. The olfactory receptor (OR) cells are neurons present in the olfactory epithelium, which is a small patch of tissue at the back of the nasal cavity. There are millions of olfactory receptor neurons that act as sensory signaling cells. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
