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Hexachlorocyclopentadiene
Hexachlorocyclopentadiene (HCCPD), also known as C-56, Graphlox, and HRS 1655, is an organochlorine compound with the formula C5Cl6. It is a precursor to pesticides, flame retardants, and dyes. It is a colourless liquid, although commercial samples appear lemon-yellow liquid sometimes with a bluish vapour. Many of its derivatives proved to be highly controversial, as studies showed them to be persistent organic pollutants. An estimated 270,000 tons were produced until 1976, and smaller amounts continue to be produced today. Two prominent manufacturers are Velsicol Chemical Corporation in the US and by Jiangsu Anpon Electrochemicals Co. in China. History HCCPD is a highly toxic organochlorine compound that was first mentioned as a diene in certain Diels-Alder reactions in 1930. The HCCPD chemical family quickly attracted increased attention with the discovery of its insecticidal properties in 1955 and extensive commercialization. However, due to extensive use, the HCCPD famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dechlorane Plus
Dechlorane plus (abbrev. ''DDC-CO'') is a polychlorinated flame retardant produced by Oxychem. Its log P is 11.27±0.94. It is produced by the Diels-Alder reaction of two equivalents of hexachlorocyclopentadiene with one equivalent of cyclooctadiene. The ''syn'' and ''anti'' isomer are formed in the approximate ratio of 1:3. Dechlorane plus syn isomer.svg, ''syn'' isomer Dechlorane plus anti isomer.svg, ''anti'' isomer Dechlorane plus was first found in the environment in 2006 in air around the Great Lakes. Since then, its environmental occurrence has been further documented in several studies including sediments of the Great Lakes; zooplankton, fish, and mussels in Lake Winnipeg and Lake Ontario; air and seawater from the Arctic to Antarctica; and Chinese air. Modeling data indicates that Dechlorane Plus may be persistent, bioaccumulative, and subject to long-range transport and that it may be candidates for Annex D evaluation under the United Nations Stockholm Convention o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dieldrin
Dieldrin is an organochloride originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin, which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to form dieldrin which is the active compound. Both dieldrin and aldrin are named after the Diels-Alder reaction which is used to form aldrin from a mixture of norbornadiene and hexachlorocyclopentadiene. Originally developed in the 1940s as an alternative to DDT, dieldrin proved to be a highly effective insecticide and was very widely used during the 1950s to early 1970s. Endrin is a stereoisomer of dieldrin. However, it is an extremely persistent organic pollutant; it does not easily break down. Furthermore, it tends to biomagnify as it is passed along the food chain. Long-term exposure has proven toxic to a very wide range of animals including humans, far greater than to the original insect targets. For this reason, it is now banned in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldrin
Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called "classic organochlorines" (COC) group of pesticides. COCs enjoyed a very sharp rise in popularity during and after The Second World War. Other noteworthy examples of COCs include DDT. After research showed that organochlorines can be highly toxic to the ecosystem through bioaccumulation, most were banned from use. It is a colourless solid. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related "cyclodiene" pesticides (a term for pesticides derived from Hexachlorocyclopentadiene) became notorious as persistent organic pollutants.Robert L. Metcalf "Insect Control" in Ullmann’s Encyclopedia of Industrial Chemistry" Wiley-VCH, Weinheim, 2002. Structure & Reactivity The structure formula of aldrin is C12H8Cl6. The molecule has a molecular weight of 364.896 g/mol. The melting point of aldrin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mirex
Mirex was an organochloride that was commercialized as an insecticide and later banned because of its impact on the environment. This white crystalline odorless solid is a derivative of cyclopentadiene. It was popularized to control fire ants but by virtue of its chemical robustness and lipophilicity it was recognized as a bioaccumulative pollutant. The spread of the red imported fire ant was encouraged by the use of Mirex, which also kills native ants that are highly competitive with the fire ants. The United States Environmental Protection Agency prohibited its use in 1976.Robert L. Metcalf "Insect Control" in Ullmann’s Encyclopedia of Industrial Chemistry" Wiley-VCH, Wienheim, 2002. It is prohibited by the Stockholm Convention on Persistent Organic Pollutants. Production and applications Mirex was first synthesized in 1946, but was not used in pesticide formulations until 1955. Mirex was produced by the dimerization of hexachlorocyclopentadiene in the presence of aluminiu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepone
Chlordecone, better known in the United States under the brand name Kepone, is an organochlorine compound and a colourless solid. It is an obsolete insecticide, now prohibited in the western world, but only after many thousands of tonnes had been produced and used.Robert L. Metcalf "Insect Control" in ''Ullmann's Encyclopedia of Industrial Chemistry'' Wiley-VCH, Wienheim, 2002. Chlordecone is a known persistent organic pollutant (POP) that was banned globally by the Stockholm Convention on Persistent Organic Pollutants in 2009.Press Release – COP4 – Geneva, 8 May 2009: Governments unite to step-up reduction on global DDT reliance and add nine new chem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organochlorine Compound
An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalent bond, covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlorine) provides common examples. The wide structural variety and divergent chemical properties of organochlorides lead to a broad range of names, applications, and properties. Organochlorine compounds have wide use in many applications, though some are of profound environmental concern, with 2,3,7,8-Tetrachlorodibenzodioxin, TCDD being one of the most notorious. Physical and chemical properties Chlorination reaction, Chlorination modifies the physical properties of hydrocarbons in several ways. These compounds are typically denser than water due to the higher atomic weight of chlorine versus hydrogen. Aliphatic organochlorides are often alkylating agents as chlorine can act as a leaving group, which can result in cellular dam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norbornadiene
Norbornadiene is an 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 ... and a bicyclic hydrocarbon. Norbornadiene is of interest as a metal-binding ligand, whose complexes are useful for homogeneous catalysis. It has been intensively studied owing to its high reactivity and distinctive structural property of being a diene that cannot isomerization, isomerize (isomers would be anti-Bredt alkenes). Norbornadiene is also a useful Diels–Alder_reaction#The_dienophile, dienophile in Diels-Alder reactions. Synthesis Norbornadiene can be formed by a Diels-Alder reaction between cyclopentadiene and acetylene : Reactions Quadricyclane, a valence isomer, can be obtained from norbornadiene by a photochemical reaction when assisted by a photochemical sensitizer, sensiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adduct
An adduct (from the Latin ''adductus'', "drawn toward" alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species. Examples include the addition of sodium bisulfite to an aldehyde to give a sulfonate. It can just be considered as a single product resulting from the direct combination of different molecules which comprises all the reactant molecules' atoms. Adducts often form between Lewis acids and Lewis bases. A good example is the formation of adducts between the Lewis acid borane and the oxygen atom in the Lewis bases, tetrahydrofuran (THF): BH3·O(CH2)4 or diethyl ether: BH3·O(CH3CH2)2. Many Lewis acids and Lewis bases reacting in the gas phase or in non-aqueous solvents to form adducts have been examined in the ECW model. Trimethylboron, trimethyltin chloride and bis(hexaflu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agrochemical
An agrochemical or agrichemical, a contraction of ''agricultural chemical'', is a chemical product used in industrial agriculture. Agrichemical refers to biocides ( pesticides including insecticides, herbicides, fungicides and nematicides) and synthetic fertilizers. It may also include hormones and other chemical growth agents. Agrochemicals are counted among speciality chemicals. Categories Biological action In most of the cases, agrochemicals refer to pesticides. * Pesticides **Insecticides ** Herbicides **Fungicides **Algaecides **Rodenticides **Molluscicides **Nematicides *Fertilisers *Soil conditioners * Liming and acidifying agents *Plant growth regulators Application method * Fumigants * Penetrant Ecology Many agrochemicals are toxic, and agrichemicals in bulk storage may pose significant environmental and/or health risks, particularly in the event of accidental spills. In many countries, use of agrichemicals is highly regulated. Government-issued permits for p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkali
In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases. Etymology The word "alkali" is derived from Arabic ''al qalīy'' (or ''alkali''), meaning ''the calcined ashes'' (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly of potassium carbonate, was mildly basic. After heating this substance with calcium hydroxide (''slaked lime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopentadiene
Cyclopentadiene is an organic compound with the chemical formula, formula C5H6.LeRoy H. Scharpen and Victor W. Laurie (1965): "Structure of cyclopentadiene". ''The Journal of Chemical Physics'', volume 43, issue 8, pages 2765-2766. It is often abbreviated CpH because the cyclopentadienyl anion is abbreviated Cp−. This colorless liquid has a strong and unpleasant odor. At room temperature, this cyclic diene dimer (chemistry), dimerizes over the course of hours to give dicyclopentadiene via a Diels–Alder reaction. This dimer can be retro-Diels–Alder reaction, restored by heating to give the monomer. The compound is mainly used for the production of cyclopentene and its derivatives. It is popularly used as a precursor to the cyclopentadienyl anion (Cp−), an important ligand in cyclopentadienyl complexes in organometallic chemistry. Production and reactions Cyclopentadiene production is usually not distinguished from dicyclopentadiene since they interconvert. They ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
