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Perchloromethyl Mercaptan
Perchloromethyl mercaptan is the organosulfur compound with the formula CCl3SCl. It is mainly used as an intermediate for the synthesis of dyes and fungicides (captan, folpet). It is a colorless oil, although commercial samples are yellowish. It is insoluble in water but soluble in organic solvents. It has a foul, unbearable, acrid odor. Perchloromethyl mercaptan is the original name. The systematic name is trichloromethanesulfenyl chloride, because the compound is a sulfenyl chloride, not a mercaptan. History It was used as a chemical warfare agent by the French in the 1915 battle of Champagne. Shortly thereafter, wartime use was abandoned due to the clear warning properties, the decomposition in the presence of iron and steel, and the easy removal of the vapor by charcoal.Sosnovsky, George "The chemistry of trichloromethanesulfenyl chloride" Chemical Reviews 1958, volume 58, 509-40. Preparation The method to prepare perchloromethyl mercaptan was first described by Rathke in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Captan
Captan is a general use pesticide (GUP) that belongs to the phthalimide class of fungicides. It is a white solid, although commercial samples appear yellow or brownish. Applications Although it can be applied on its own, Captan is often added as a component of other pesticide mixtures. It is used to control diseases on a number of fruits and vegetables as well as ornamental plants. It also improves the outward appearance of many fruits, making them brighter and healthier-looking. Captan is utilized by both home and agricultural growers and is often applied during apple production. It is also active against certain oomycetes, such as Pythium, making it useful for controlling damping off. Biodegradation The compound biodegrades with halflife of less than 1 day in soil. Potential health effects Captan was previously cited as Group B2, a probable human carcinogen by the US Environmental Protection Agency (EPA), but was reclassified in 2004. Since the mode of action has been esta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folpet
Folpet is the tradename for the organic compound with the formula C6H4(CO)2NSCCl3. It is a fungicide derived from phthalimide (C6H4(CO)2N-) and trichloromethylsulfenyl chloride. The compound is white although commercial samples can appear brownish. It is structurally related to Captan, which is also a trichloromethylsulfenyl-containing fungicide. Resistance folpet resistance is still unheard of due to its multiple effects. However, in 2001 some degree of ''cross''-resistance was reported in iprodione-resistant South African ''Botrytis cinerea'' on grape. References {{reflist, refs= {{cite web , title=Folpet: the essential multi-site fungicide , website=ADAMA UK , url=http://www.adama.com/uk/en/news-and-media/adama-news/folpet-the-essential-multi-site-fungicide , access-date=2021-03-13 , date=2019-12-11 {{cite journal , last1=Fourie , first1=P.H. , last2=Holz , first2=G. , title=Incomplete Cross-Resistance to Folpet and Iprodione in ''Botrytis cinerea'' from Grape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfenyl Chloride
In organosulfur chemistry, a sulfenyl chloride is a functional group with the connectivity , where R is alkyl or aryl. Sulfenyl chlorides are reactive compounds that behave as sources of . They are used in the formation of and bonds. According to IUPAC nomenclature they are named as alkyl thiohypochlorites, i.e. esters of thiohypochlorous acid. Preparation Sulfenyl chlorides are typically prepared by chlorination of disulfides: :R2S2 + Cl2 -> 2 R-SCl This reaction is sometimes called the Zincke disulfide reaction, in recognition of Theodor Zincke. Typically, sulfenyl halides are stabilized by electronegative substituents. This trend is illustrated by the stability of obtained by chlorination of carbon disulfide. Some thioethers () with electron-withdrawing substituents undergo chlorinolysis of a bond to afford the sulfenyl chloride. Reactions Perchloromethyl mercaptan () reacts with bonds in the presence of base to give the sulfenamides: :CCl3SCl + R2NH -> CCl3SNR2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercaptan
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 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. 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 group () bonds very strong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Warfare
Chemical warfare (CW) involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from nuclear warfare, biological warfare and radiological warfare, which together make up CBRN, the military acronym for chemical, biological, radiological, and nuclear (warfare or weapons), all of which are considered "weapons of mass destruction" (WMDs), a term that contrasts with conventional weapons. The use of chemical weapons is prohibited under customary international humanitarian law. Definition Chemical warfare is different from the use of conventional weapons or nuclear weapons because the destructive effects of chemical weapons are not primarily due to any explosive force. The offensive use of living organisms (such as anthrax) is considered biological warfare rather than chemical warfare; however, the use of nonliving toxic products produced by living organisms (e.g. toxins such as botulinum toxin, ricin, and saxitoxin) ''is'' consider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Disulfide
Carbon disulfide (also spelled as carbon disulphide) is a neurotoxic, colorless, volatile liquid with the formula and structure . The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent. It has an "ether-like" odor, but commercial samples are typically contaminated with foul-smelling impurities.. It is of comparable toxicity to carbon monoxide. History In 1796, the German chemist Wilhelm August Lampadius (1772–1842) first prepared carbon disulfide by heating pyrite with moist charcoal. He called it "liquid sulfur" (''flüssig Schwefel''). The composition of carbon disulfide was finally determined in 1813 by the team of the Swedish chemist Jöns Jacob Berzelius (1779–1848) and the Swiss-British chemist Alexander Marcet (1770–1822). Their analysis was consistent with an empirical formula of CS2. Occurrence, manufacture, properties Small amounts of carbon disulfide are released by volcanic eruptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Tetrachloride
Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVACR) is an organic compound with the chemical formula CCl4. It is a colourless liquid with a "sweet" smell that can be detected at low levels. It is practically incombustible at lower temperatures. It was formerly widely used in fire extinguishers, as a precursor to refrigerants and as a cleaning agent, but has since been phased out because of environmental and safety concerns. Exposure to high concentrations of carbon tetrachloride (including vapor) can affect the central nervous system and degenerate the liver and kidneys. Prolonged exposure can be fatal. Properties In the carbon tetrachloride molecule, four chlorine atoms are positioned symmetrically as corners in a tetrahedron, tetrahedral configuration joined to a central carbon atom by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diketone
In organic chemistry, a dicarbonyl is a molecule containing two carbonyl () groups. Although this term could refer to any organic compound containing two carbonyl groups, it is used more specifically to describe molecules in which both carbonyls are in close enough proximity that their reactivity is changed, such as 1,2-, 1,3-, and 1,4-dicarbonyls. Their properties often differ from those of monocarbonyls, and so they are usually considered functional groups of their own. These compounds can have symmetrical or unsymmetrical substituents on each carbonyl, and may also be functionally symmetrical (dialdehydes, diketones, diesters, ''etc.'') or unsymmetrical (keto-esters, keto-acids, ''etc.''). 1,2-Dicarbonyls 1,2-Dialdehyde The only 1,2-dialdehyde is glyoxal, . Like many alkyldialdehydes, glyoxal is encountered almost exclusively as its hydrate and oligomers thereof. These derivatives often behave equivalently to the aldehydes since hydration is reversible. Glyoxal condenses re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiophosgene
Thiophosgene is a red liquid with the formula . It is a molecule with trigonal planar geometry. There are two reactive C–Cl bonds that allow it to be used in diverse organic syntheses. Preparation is prepared in a two-step process from carbon disulfide. In the first step, carbon disulfide is chlorinated to give trichloromethanesulfenyl chloride ( perchloromethyl mercaptan), : : The chlorination must be controlled as excess chlorine converts trichloromethanesulfenyl chloride into carbon tetrachloride. Steam distillation separates the trichloromethanesulfenyl chloride, a rare sulfenyl chloride, and hydrolyzes the sulfur monochloride. Reduction of trichloromethanesulfenyl chloride produces thiophosgene: : Tin and dihydroanthracene have been used for the reducing agents. Reactions is mainly used to prepare compounds with the connectivity where X = OR, NHR. Such reactions proceed via intermediate such as CSClX. Under certain conditions, one can convert primary amines into isothi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Dichloride
Sulfur dichloride is the chemical compound with the formula . This cherry-red liquid is the simplest sulfur chloride and one of the most common, and it is used as a precursor to organosulfur compounds. It is a highly corrosive and toxic substance, and it reacts on contact with water to form chlorine-containing acids. Chlorination of sulfur is produced by the chlorination of either elemental sulfur or disulfur dichloride. The process occurs in a series of steps, some of which are: :; ''ΔH'' = −58.2 kJ/mol :; ''ΔH'' = −40.6 kJ/mol The addition of to has been proposed to proceed via a mixed valence intermediate . undergoes even further chlorination to give , but this species is unstable at near room temperature. It is likely that several exist where ''n'' > 2. Disulfur dichloride, , is the most common impurity in . Separation of from is possible via distillation with to form an azeotrope of 99% purity, however sulfur dichloride loses chlorine slowly at room temperatu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distillation
Distillation, or classical distillation, is the process of separation process, separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids); this may involve chemical changes such as destructive distillation or Cracking (chemistry), cracking. Distillation may result in essentially complete separation (resulting in nearly pure components), or it may be a partial separation that increases the concentration of selected components; in either case, the process exploits differences in the relative volatility of the mixture's components. In Chemical industry, industrial applications, distillation is a unit operation of practically universal importance, but is a physical separation process, not a chemical reaction. An installation used for distillation, especially of distilled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiling Points
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid varies depending upon the surrounding environmental pressure. A liquid in a partial vacuum has a lower boiling point than when that liquid is at atmospheric pressure. A liquid at low pressure has a lower boiling point than when that liquid is at atmospheric pressure. Because of this, water boils at under standard pressure at sea level, but at at altitude. For a given pressure, different liquids will boil at different temperatures. The normal boiling point (also called the atmospheric boiling point or the atmospheric pressure boiling point) of a liquid is the special case in which the vapor pressure of the liquid equals the defined atmospheric pressure at sea level, one atmosphere. At that temperature, the vapor pressure of the liquid becomes sufficient to overcome atmospheric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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