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1,2-Dichlorobenzene
1,2-Dichlorobenzene, or orthodichlorobenzene (ODCB), is an organic compound with the formula CHCl. This colourless liquid is poorly soluble in water but miscible with most organic solvents. It is a derivative of benzene, consisting of two adjacent chlorine atoms. It is mainly used as a precursor chemical in the synthesis of agrochemicals, as a preferred solvent for dissolving and working with fullerenes, as an insecticide, and in softening and removing carbon-based contamination on metal surfaces. Production and uses 1,2-Dichlorobenzene is obtained as a side-product of the production of chlorobenzene: : + → + HCl The reaction also affords the 1,4- and small amounts of the 1,3-isomer. The 1,4- isomer is preferred over the 1,2- isomer due to steric hindrance. The 1,3- isomer is uncommon because it is a meta- compound, while chlorine, like all halogens, is an ortho/para- director in terms of electrophilic aromatic substitution. It is mainly used as a precursor to 1,2- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halogenated Solvents
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemical synt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,4-Dichlorobenzene
1,4-Dichlorobenzene (1,4-DCB, ''p''-DCB, or ''para''-dichlorobenzene, sometimes abbreviated as PDCB or para) is an organic compound with the formula C6H4Cl2. This colorless solid has a strong odor. The molecule consists of a benzene ring with two chlorine atoms (replacing hydrogen atoms) on opposing sites of the ring. It is used as a disinfectant, pesticide, and deodorant, most familiarly in mothballs in which it is a replacement for the more traditional naphthalene because of naphthalene's greater flammability (though both chemicals have the same NFPA 704 rating). It is also used as a precursor in the production of the chemically and thermally resistant polymer poly(''p''-phenylene sulfide). Production ''p''-DCB is produced by chlorination of benzene using ferric chloride as a catalyst: :C6H6 + 2 Cl2 → C6H4Cl2 + 2 HCl The chief impurity is the 1,2 isomer. The compound can be purified by fractional crystallization, taking advantage of its relatively high melting poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,3-Dichlorobenzene
1,3-Dichlorobenzene (also known as meta-dichlorobenzene) is an organic compound with the formula C6H4Cl2. It is the least common of the three isomers of dichlorobenzene, and it is a colorless liquid that is insoluble in water. It is produced as a minor byproduct of the chlorination of benzene, but can also be prepared in a directed manner by the Sandmeyer reaction of 3-chloroaniline. It also arises from the isomerization of the other dichlorobenzenes at high temperature. Hazards This chemical is combustible. "Hazardous decomposition products" are carbon monoxide, carbon dioxide, chlorine, hydrogen chloride gas. It is toxic to aquatic life with long-lasting effects. See also Other isomers: * 1,2-Dichlorobenzene * 1,4-Dichlorobenzene Other halides: * Dibromobenzene Dibromobenzene may refer to: * 1,2-Dibromobenzene (''o''-dibromobenzene) * 1,3-Dibromobenzene (''m''-dibromobenzene) * 1,4-Dibromobenzene 1,4-Dibromobenzene (''p''-dibromobenzene) is an organic compound that i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophilic Aromatic Substitution
Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic nitration, aromatic halogenation, aromatic sulfonation, and alkylation and acylation Friedel–Crafts reaction. Illustrative reactions The most widely practised example of this reaction is the ethylation of benzene. :: Approximately 24,700,000 tons were produced in 1999. (After dehydrogenation and polymerization, the commodity plastic polystyrene is produced.) In this process, acids are used as catalyst to generate the incipient carbocation. Many other electrophilic reactions of benzene are conducted, although on a much smaller scale; they are valuable routes to key intermediates. The nitration of benzene is achieved via the action of the nitronium ion as the electrophile. The sulfonation with fuming sulfuric acid gives benzenesulfonic ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organochloride Insecticides
An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one 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 TCDD being one of the most notorious. Physical and chemical properties 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 damage. Natural occurrence Many organochlorine compounds have been isolate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorobenzenes
Chlorobenzene is an aromatic organic compound with the chemical formula C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals. Uses Historical The major use of chlorobenzene is as an intermediate in the production of herbicides, dyestuffs, and rubber. Chlorobenzene is also used as a high-boiling solvent in industrial applications as well as in the laboratory. Chlorobenzene is nitrated on a large scale to give a mixture of 2-nitrochlorobenzene and 4-nitrochlorobenzene, which are separated. These mononitrochlorobenzenes are converted to related 2-nitrophenol, 2-nitroanisole, bis(2-nitrophenyl)disulfide, and 2-nitroaniline by nucleophilic displacement of the chloride, with respectively sodium hydroxide, sodium methoxide, sodium disulfide, and ammonia. The conversions of the 4-nitro derivative are similar. Chlorobenzene once was used in the manufacture of pesticides, most notably DDT, by reaction with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorobenzene
Chlorobenzene is an aromatic organic compound with the chemical formula C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals. Uses Historical The major use of chlorobenzene is as an intermediate in the production of herbicides, dyestuffs, and rubber. Chlorobenzene is also used as a high-boiling solvent in industrial applications as well as in the laboratory. Chlorobenzene is nitrated on a large scale to give a mixture of 2-nitrochlorobenzene and 4-nitrochlorobenzene, which are separated. These mononitrochlorobenzenes are converted to related 2-nitrophenol, 2-nitroanisole, bis(2-nitrophenyl)disulfide, and 2-nitroaniline by nucleophilic displacement of the chloride, with respectively sodium hydroxide, sodium methoxide, sodium disulfide, and ammonia. The conversions of the 4-nitro derivative are similar. Chlorobenzene once was used in the manufacture of pesticides, most notably DDT, by reaction with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Institute For Occupational Safety And Health
The National Institute for Occupational Safety and Health (NIOSH, ) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the Centers for Disease Control and Prevention (CDC) within the U.S. Department of Health and Human Services. Despite its name, it is not part of the National Institutes of Health. Its current director is John Howard. NIOSH is headquartered in Washington, D.C., with research laboratories and offices in Cincinnati, Ohio; Morgantown, West Virginia; Pittsburgh, Pennsylvania; Denver, Colorado; Anchorage, Alaska; Spokane, Washington; and Atlanta, Georgia. NIOSH is a professionally diverse organization with a staff of 1,200 people representing a wide range of disciplines including epidemiology, medicine, industrial hygiene, safety, psychology, engineering, chemistry, and statistics. The Occupational Safety and Health Act, signed by President Rich ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occupational Safety And Health Administration
The Occupational Safety and Health Administration'' (OSHA ) is a large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agency under the Occupational Safety and Health Act OSH Act, which President Richard M. Nixon signed into law on December 29, 1970. OSHA's mission is to "assure safe and healthy working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education, and assistance". The agency is also charged with enforcing a variety of whistleblower statutes and regulations. OSHA's workplace safety inspections have been shown to reduce injury rates and injury costs without adverse effects on employment, sales, credit ratings, or firm survival. History The Bureau of Labor Standards of the Department of Labor has worked on some work safety issues since its creation in 1922. Economic boom and associated l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Forest Service
The United States Forest Service (USFS) is an agency of the U.S. Department of Agriculture that administers the nation's 154 national forests and 20 national grasslands. The Forest Service manages of land. Major divisions of the agency include the Chief's Office, National Forest System, State and Private Forestry, Business Operations, and Research and Development. The agency manages about 25% of federal lands and is the only major national land management agency not part of the U.S. Department of the Interior, which manages the National Park Service, the U.S. Fish and Wildlife Service, and the Bureau of Land Management. History The concept of national forests was born from Theodore Roosevelt's conservation group, Boone and Crockett Club, due to concerns regarding Yellowstone National Park beginning as early as 1875. In 1876, Congress formed the office of Special Agent in the Department of Agriculture to assess the quality and conditions of forests in the United States. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Dichloro-4-nitrobenzene
1,2-Dichloro-4-nitrobenzene is an organic compound with the formula 1,2-ClCH-4-NO. This pale yellow solid is related to 1,2-dichlorobenzene by the replacement of one H atom with a nitro functional group. This compound is an intermediate in the synthesis of agrochemicals. Production and uses The nitration of 1,2-dichlorobenzene mainly produces 1,2-dichloro-4-nitrobenzene, together with smaller amounts of the 3-nitro isomer. It can also be prepared by chlorination of 1-chloro-4-nitrobenzene.Gerald Booth (2007). "Nitro Compounds, Aromatic" in ''Ullmann's Encyclopedia of Industrial Chemistry'' Wiley-VCH, Weinheim, 2005. One of the chlorides is reactive toward nucleophiles. Potassium fluoride gives 2-chloro-1-fluoro-4-nitrobenzene, an intermediate in the production of herbicides. With ammonia, one obtains 2-chloro-4-nitroaniline, a precursor to diazo The diazo group is an organic moiety consisting of two linked nitrogen atoms ( azo) at the terminal position. Overall charge n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merck Index
''The Merck Index'' is an encyclopedia of chemical substance, chemicals, pharmaceutical drug, drugs and biomolecule, biologicals with over 10,000 monographs, monograph on single substances or groups of related chemical compound, compounds published online by the Royal Society of Chemistry. History The first edition of the Merck's Index was published in 1889 by the German chemical company Merck Group, Emanuel Merck and was primarily used as a sales catalog for Merck's growing list of chemicals it sold. The American subsidiary was established two years later and continued to publish it. During World War I the US government seized Merck's US operations and made it a separate American "Merck" company that continued to publish the Merck Index. In 2012 the Merck Index was licensed to the Royal Society of Chemistry. An online version of The Merck Index, including historic records and new updates not in the print edition, is commonly available through research libraries. It also include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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