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Cobaloxime
Dimethylglyoxime is a chemical compound described by the formula CH3C(NOH)C(NOH)CH3. Its abbreviation is dmgH2 for neutral form, and dmgH− for anionic form, where H stands for hydrogen. This colourless solid is the dioxime derivative of the diketone butane-2,3-dione (also known as diacetyl). DmgH2 is used in the analysis of palladium or nickel. Its coordination complexes are of theoretical interest as models for enzymes and as catalysts. Many related Ligand, ligands can be prepared from other diketones, e.g. benzil. Preparation Dimethylglyoxime can be prepared from butanone first by reaction with ethyl nitrite to give biacetyl monoxime. The second oxime is installed using sodium hydroxylamine monosulfonate: Complexes Dimethylglyoxime forms complexes with metals including nickel, palladium and cobalt. These complexes are used to separate those cations from solutions of metal salts and in gravimetric analysis. It is also used in precious metals refining to precipitate palladi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxylamine
Hydroxylamine is an inorganic compound with the formula . The material is a white crystalline, hygroscopic compound.Greenwood and Earnshaw. ''Chemistry of the Elements.'' 2nd Edition. Reed Educational and Professional Publishing Ltd. pp. 431–432. 1997. Hydroxylamine is almost always provided and used as an aqueous solution. It is consumed almost exclusively to produce Nylon-6. It is also an intermediate in biological nitrification. The oxidation of to hydroxylamine is a step in biological nitrification. History Hydroxylamine was first prepared as hydroxylammonium chloride in 1865 by the German chemist Wilhelm Clemens Lossen (1838-1906); he reacted tin and hydrochloric acid in the presence of ethyl nitrate. It was first prepared in pure form in 1891 by the Dutch chemist Lobry de Bruyn and by the French chemist Léon Maurice Crismer (1858-1944). The coordination complex , known as Crismer's salt, releases hydroxylamine upon heating. Production Hydroxylamine or its salts can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethyl Nitrite
The chemical compound ethyl nitrite is an alkyl nitrite with a chemical formula C2H5NO2. It may be prepared from ethanol. : Uses It is used as a reagent with butanone to yield the dimethylglyoxime end product. Ethyl nitrite is the main ingredient in a traditional ethanol-based South African remedy for colds and flu known as ''Witdulsies'', which is sold in pharmacies. It is known as a traditional Afrikaans remedy; the same remedy is apparently made by the Amish in the US. However, FDA has blocked over-the-counter sales of this same remedy, known in the US as ''sweet nitrite'' or ''sweet spirit of nitre'', since 1980. Its use has been associated with fatal methemoglobinemia. Methemoglobinemia Methemoglobinemia, or methaemoglobinaemia, is a condition of elevated methemoglobin in the blood. Symptoms may include headache, dizziness, shortness of breath, nausea, poor muscle coordination, and blue-colored skin (cyanosis). Complications ma ... is the primary toxic effect of ethy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel Bis(dimethylglyoximate)
Nickel bis(dimethylglyoximate) is the coordination complex with the formula Ni NC(CH3)C(CH3)NOHsub>2. The compound is a bright red solid. It achieved prominence for its use in the qualitative analysis of nickel. Structure The geometry of the nickel(II) ion is square planar. It is surrounded by two equivalents of the conjugate base (dmgH−) of dimethylglyoxime (dmgH2). The pair of organic ligands are joined through hydrogen bonds to give a macrocyclic ligand. The complex is distinctively colored and insoluble leading to its use as a chelating agent in the gravimetric analysis of nickel. The use of dimethylglyoxime as a reagent to detect nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ... was reported by L. A. Chugaev in 1905.{{cite journal , title = Über ein neue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palladium Chloride
Palladium(II) chloride, also known as palladium dichloride and palladous chloride, are the chemical compounds with the formula PdCl2. PdCl2 is a common starting material in palladium chemistry – palladium-based catalysts are of particular value in organic synthesis. It is prepared by the reaction of chlorine with palladium metal at high temperatures. Structure Two forms of PdCl2 are known, denoted α and β. In both forms, the palladium centres adopt a square-planar coordination geometry that is characteristic of Pd(II). Furthermore, in both forms, the Pd(II) centers are linked by μ2-chloride bridges. The α-form of PdCl2 is a polymer, consisting of "infinite" slabs or chains. The β-form of PdCl2 is molecular, consisting of an octahedral cluster of six Pd atoms. Each of the twelve edges of this octahedron is spanned by Cl−. PtCl2 adopts similar structures, whereas NiCl2 adopts the CdCl2 motif, featuring hexacoordinated Ni(II). Two further polymorphs, γ-PdCl2 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precious Metals Refining
In metallurgy, refining consists of purifying an impure metal. It is to be distinguished from other processes such as smelting and calcining in that those two involve a chemical change to the raw material, whereas in refining, the final material is usually identical chemically to the original one, only it is purer. The processes used are of many types, including pyrometallurgical and hydrometallurgical techniques. Lead Cupellation One ancient process for extracting the silver from lead was cupellation. Lead was melted in a bone ash 'test' or 'cupel' and air blown across the surface. This oxidised the lead to litharge, and also oxidised other base metals present, the silver (and gold if present) remaining unoxidised. In the 18th century, the process was carried on using a kind of reverberatory furnace, but differing from the usual kind in that air was blown over the surface of the molten lead from bellows or (in the 19th century) blowing cylinders. Pattinson process The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravimetric Analysis
Gravimetric analysis describes a set of methods used in analytical chemistry Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separati ... for the quantitative determination of an analyte (the ion being analyzed) based on its mass. The principle of this type of analysis is that once an ion's mass has been determined as a unique compound, that known measurement can then be used to determine the same analyte's mass in a mixture, as long as the relative quantities of the other constituents are known. The four main types of this method of analysis are ''precipitation'', ''volatilization'', ''electro-analytical'' and ''miscellaneous physical method''. The methods involve changing the phase of the analyte to separate it in its pure form from the original mixture and are quantitative measurements ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalt
Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was for a long time thought to be due to the known metal bismuth. Miners had long used the name '' kobold ore'' (German for ''goblin ore'') for some of the blue-pigment-producing minerals; they were so named because they were poor in known metals, and gave poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the ''kobold''. Today, some cobalt is produced specifically from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preparation Of Dimethylglyoxime
Preparation may refer to: * Preparation (dental), the method by which a tooth is prepared when removing decay and designing a form that will provide adequate retention for a dental restoration * Preparation (music), treatment of dissonance in tonal music * Preparation, Iowa, a ghost town * Preparation time, time to prepare speeches in policy debate * '' The Preparation'', a 2017 South Korean film * ''Preparations'' (album), a 2007 album by Prefuse 73 * Prepared dosage form * Prepared drug * Prepared food * Prepared supplement * Special modifications to instruments, see **Prepared piano **Prepared guitar * Fossil preparation See also * Preparation H, popular hemorrhoids medicine * Preparation for the Gospel, early Christian book * * Prep (other) * Preparationism * Prepare (other) * Preparedness (other) Preparedness refers to actions that are taken as precautionary measures in the face of potential disasters Preparedness may also refer to: * E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxylamine
Hydroxylamine is an inorganic compound with the formula . The material is a white crystalline, hygroscopic compound.Greenwood and Earnshaw. ''Chemistry of the Elements.'' 2nd Edition. Reed Educational and Professional Publishing Ltd. pp. 431–432. 1997. Hydroxylamine is almost always provided and used as an aqueous solution. It is consumed almost exclusively to produce Nylon-6. It is also an intermediate in biological nitrification. The oxidation of to hydroxylamine is a step in biological nitrification. History Hydroxylamine was first prepared as hydroxylammonium chloride in 1865 by the German chemist Wilhelm Clemens Lossen (1838-1906); he reacted tin and hydrochloric acid in the presence of ethyl nitrate. It was first prepared in pure form in 1891 by the Dutch chemist Lobry de Bruyn and by the French chemist Léon Maurice Crismer (1858-1944). The coordination complex , known as Crismer's salt, releases hydroxylamine upon heating. Production Hydroxylamine or its salts can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biacetyl Monoxime
Diacetyl monoxime is a chemical compound described by the formula CH3C(O)C(NOH)CH3. This colourless solid is the monooxime derivative of the diketone butane-2,3-dione (also known as diacetyl and biacetyl). Its biological effects include inhibiting certain ATPases. Preparation The compound can be prepared from butanone by reaction with ethyl nitrite. It is an intermediate in the preparation of dimethylglyoxime Dimethylglyoxime is a chemical compound described by the formula CH3C(NOH)C(NOH)CH3. Its abbreviation is dmgH2 for neutral form, and dmgH− for anionic form, where H stands for hydrogen. This colourless solid is the di oxime derivative of the dik ...: : Uses Diacetyl monoxime can be used with thiosemicarbazide to selectively detect small amounts of urea in the presence of other nitrogen-containing compounds. References {{Reflist Ketoximes Chelating agents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butanone
Butanone, also known as methyl ethyl ketone (MEK), is an organic compound with the formula CH3C(O)CH2CH3. This colourless liquid ketone has a sharp, sweet odor reminiscent of acetone. It is produced industrially on a large scale, but occurs in nature only in trace amounts.Wilhelm Neier, Guenter Strehlke "2-Butanone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. It is partially soluble in water, and is commonly used as an industrial solvent. It is an isomer of another solvent, tetrahydrofuran. Production Butanone may be produced by oxidation of 2-butanol. The dehydrogenation of 2-butanol is catalysed by copper, zinc, or bronze: :CH3CH(OH)CH2CH3 → CH3C(O)CH2CH3 + H2 This is used to produce approximately 700 million kilograms yearly. Other syntheses that have been examined but not implemented include Wacker oxidation of 2-butene and oxidation of isobutylbenzene, which is analogous to the industrial production of acetone. The cumene p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salicylaldoxime
Salicylaldoxime is an organic compound described by the formula C6H4CH=NOH-2-OH. It is the oxime of salicylaldehyde. This crystalline, colorless solid is a chelator and sometimes used in the analysis of samples containing transition metal ions, with which it often forms brightly coloured coordination complexes. Reactions Salicylaldoxime is the conjugate acid of a bidentate ligand: :2 C6H4CH=NOH-2-OH + Cu2+ → Cu(C6H4CH=NOH-2-O)2 + 2 H+ In highly acidic media, the ligand decomplexes and the metal aqua complex is liberated. In this way the ligand is used as a recyclable extractant. It typically forms charge-neutral complexes with divalent metal ions. Analytical chemistry In the era when metals were analysed by spectrophotometry, many chelating ligands were developed that selectively formed brightly coloured complexes with particular metal ions. This methodology has been eclipsed with the introduction of inductively coupled plasma methodology. Salicylaldoxime can be u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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