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Pentachlorobenzene
Pentachlorobenzene (PeCB) is an aryl chloride and a five-substituted chlorobenzene with the molecular formula C6HCl5 which is a chlorinated aromatic hydrocarbon. It consists of a benzene ring substituted with five chlorine atoms. PeCB was once used industrially for a variety of uses, but because of environmental concerns there are currently no large scale uses of PeCB.Pentachlorobenzene – Sources, environmental fate and risk characterization , Robert E. Bailey, EuroChlor, July 2007 Pentachlorobenzene is a known (POP) and banned globally by the |
Pentachlorobenzenethiol
Pentachlorobenzenethiol is a chemical compound from the group of thiols and organochlorine compounds. The chemical formula is . Synthesis Pentachlorobenzenethiol can be obtained from hexachlorobenzene. Properties Pentachlorobenzenethiol is a combustible gray solid with an unpleasant odor, practically insoluble in water. It has a monoclinic crystal structure. The compound is not well-biodegradable and presumably bioaccumulable and toxic for aquatic organisms. Pentachlorobenzenethiol is itself a metabolite of hexachlorobenzene and is found in the urine and the excretions of animals receiving hexachlorobenzene. Pentachlorobenzenethiol has a high potential for long-range transport via air as it is very slowly degraded in atmosphere. Applications Pentachlorobenzenethiol is used in the rubber industry. The compound is added to rubber (both natural and synthetic) to facilitate processing (mastication). See also *Chlorobenzene *Dichlorobenzene *Trichlorobenzene *Pentachlorobenzene *Hex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistent Organic Pollutants
Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic and adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released. The effect of POPs on human and environmental health was discussed, with intention to eliminate or severely restrict their production, by the international community at the Stockholm Convention on Persistent Organic Pollutants in 2001. Most POPs are pesticides or insecticides, and some are also solvents, pharmaceuticals, and industrial chemicals. Although some POPs arise naturally (e.g. from volcanoes), most are man-made. The "dirty dozen" POPs identified by the Stockholm Convention include aldrin, chlordane, dieldrin, endrin, heptachlor, HCB, mirex, toxaphene, PCBs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistent Organic Pollutant
Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic and adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released. The effect of POPs on human and environmental health was discussed, with intention to eliminate or severely restrict their production, by the international community at the Stockholm Convention on Persistent Organic Pollutants in 2001. Most POPs are pesticides or insecticides, and some are also solvents, pharmaceuticals, and industrial chemicals. Although some POPs arise naturally (e.g. from volcanoes), most are man-made. The "dirty dozen" POPs identified by the Stockholm Convention include aldrin, chlordane, dieldrin, endrin, heptachlor, HCB, mirex, toxaphene, PCBs, DDT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentachlorotoluene
Pentachlorotoluene is a synthetic organochlorine compound with the molecular formula . This is an organic chemical compound from the group of aromatics and a derivative of toluene. Synthesis Pentachlorotoluene can be synthesized by chlorination of toluene. Physical properties This compound forms a white solid with a distinctive smell. The chlorine atoms contribute to its density, making it heavier than water. Because of its low volatility and fat-loving nature, pentachlorotoluene tends to build up in organic tissues, raising concerns in environmental and health research. Uses The compound is traditionally employed as an intermediate in the production of various chemicals, such as pesticides and pharmaceuticals. Nevertheless, because of its environmental persistence, tendency to bioaccumulate, and harmful effects on humans and wildlife, its usage has been significantly limited in numerous countries. See also *Hexachlorobenzene * Pentabromotoluene *Pentachlorobenzene Pentachlorob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorobenzenes
Chlorobenzenes are a group of aryl chlorides/ halobenzenes consisting of one or more chlorine atoms as substituents on a benzene core. They have the formula C6H6–''n''Cl''n'', where ''n'' = 1–6 is the number of chlorine atoms. Depending on the number of chlorine substituents, there may be several constitutional isomers possible. * Monochlorobenzene * Dichlorobenzene ** 1,2-Dichlorobenzene ** 1,3-Dichlorobenzene ** 1,4-Dichlorobenzene * Trichlorobenzene ** 1,2,3-Trichlorobenzene ** 1,2,4-Trichlorobenzene ** 1,3,5-Trichlorobenzene * Tetrachlorobenzene ** 1,2,3,4-Tetrachlorobenzene ** 1,2,3,5-Tetrachlorobenzene ** 1,2,4,5-Tetrachlorobenzene * Pentachlorobenzene * Hexachlorobenzene Hexachlorobenzene, or perchlorobenzene, is an aryl chloride and a six-substituted chlorobenzene with the molecular formula C6Cl6. It is a fungicide formerly used as a seed treatment, especially on wheat to control the fungal disease bunt. Its u ... See also * Fluorobenzenes * Bromobenzen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentafluorobenzene
Pentafluorobenzene is a synthetic organofluoride compound with the molecular formula . The compound consists of a benzene ring substituted with five fluorine atoms. The substance is a colorless liquid with a boiling point similar to that of benzene.''CRC Handbook of Chemistry and Physics'', 90. Edition, CRC Press, Boca Raton, Florida, 2009, , Section 3, ''Physical Constants of Organic Compounds'', p. 3-414. It is prepared by defluorination of highly fluorinated cyclohexanes over hot nickel or iron. Another method involved dehydrofluorination of polyfluorinated cyclohexane using hot aqueous solution of potassium hydroxide. It has been observed as a degradation by-product of the incineration of polytetrafluoroethylene and of biosolids. Safety According to its Safety Data Sheet (SDS), the chemical is highly flammable, and is harmful if swallowed. The SDS states its "toxicological properties have not been fully investigated". Combustion by-products include hydrogen fluoride. Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stockholm Convention On Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed on 22 May 2001 in Stockholm and effective from 17 May 2004, that aims to eliminate or restrict the production and use of persistent organic pollutants (POPs). History In 1995, the Governing Council of the United Nations Environment Programme (UNEP) called for global action to be taken on POPs, which it defined as "chemical substances that persist in the environment, bio-accumulate through the food web, and pose a risk of causing adverse effects to human health and the environment". Following this, the Intergovernmental Forum on Chemical Safety (IFCS) and the International Programme on Chemical Safety (IPCS) prepared an assessment of the 12 worst offenders, known as the ''dirty dozen''. The INC met five times between June 1998 and December 2000 to elaborate the convention, and delegates adopted the Stockholm Convention on POPs at the Conference of the Plenipotentiaries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrobenzene
Nitrobenzene is an aromatic nitro compound and the simplest of the nitrobenzenes, with the chemical formula C6H5 NO2. It is a water-insoluble pale yellow oil with an almond-like odor. It freezes to give greenish-yellow crystals. It is produced on a large scale from benzene as a precursor to aniline. In the laboratory, it is occasionally used as a solvent, especially for electrophilic reagents. As confirmed by X-ray crystallography, nitrobenzene is a planar molecule. Production Nitrobenzene is prepared by nitration of benzene with a mixture of concentrated sulfuric acid, water, and nitric acid. This mixture is sometimes called "mixed acid." The production of nitrobenzene is one of the most dangerous processes conducted in the chemical industry because of the exothermicity of the reaction (Δ''H'' = −117 kJ/mol). World capacity for nitrobenzene in 1985 was about 1,700,000 tonnes. The nitration process involves formation of the nitronium ion (NO2+), followed by an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polychlorinated Dibenzofuran
Polychlorinated dibenzofurans (PCDFs) are a family of organic compounds with one or several of the hydrogens in the dibenzofuran structure replaced by chlorines. For example, 2,3,7,8-tetrachlorodibenzofuran (TCDF) has chlorine atoms substituted for each of the hydrogens on the number 2, 3, 7, and 8 carbons (see structure in the upper left corner of the second image). Polychlorinated dibenzofurans with chlorines at least in positions 2,3,7 and 8 are much more toxic than the parent compound dibenzofuran, with properties and chemical structures similar to polychlorinated dibenzodioxins. These groups together are often inaccurately called dioxins. They are known developmental toxicants, and suspected human carcinogens. PCDFs tend to co-occur with polychlorinated dibenzodioxins (PCDDs). PCDFs can be formed by pyrolysis or incineration at temperatures below 1200 °C of chlorine containing products, such as PVC, PCBs, and other organochlorides, or of non-chlorine containing prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polychlorinated Dibenzodioxins
Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of long-lived polyhalogenated organic compounds that are primarily anthropogenic, and contribute toxic, persistent organic pollution in the environment. They are commonly but inaccurately referred to as dioxins for simplicity, because every PCDD molecule contains a dibenzo-1,4-dioxin skeletal structure, with 1,4-dioxin as the central ring. Members of the PCDD family bioaccumulate in humans and wildlife because of their lipophilic properties, and may cause developmental disturbances and cancer. Because dioxins can persist in the environment for more than 100 years, the majority of PCDD pollution today is not the result of recent emissions, but the cumulative result of synthetic processes undertaken since the beginning of the 20th century, including organochloride-related manufacturing, incineration of chlorine-containing substances such as polyvinyl chloride (PVC), and chlorine bleaching of paper. For ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Chloride
The Chemical compound, compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride gas and hydrochloric acid are important in technology and industry. Hydrochloric acid, the aqueous solution of hydrogen chloride, is also commonly given the formula HCl. Reactions Hydrogen chloride is a diatomic molecule, consisting of a hydrogen atom H and a chlorine atom Cl connected by a Polar-covalent bond, polar covalent bond. The chlorine atom is much more Electronegativity, electronegative than the hydrogen atom, which makes this bond polar. Consequently, the molecule has a large Molecular dipole moment, dipole moment with a negative partial charge (δ−) at the chlorine atom and a positive partial charge (δ+) at the hydrogen atom. In part because of its high polarity, HCl is very soluble in water (and in other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
