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Carbazone
In chemistry, a carbazide is a functional group with the general formula RNH-NH(C=O)NH-NHR. They can be derived from the condensation of carbonic acid with a hydrazine. Carbohydrazide is the simplest carbazide, with another common carbazide being diphenylcarbazide, which is used as an analytical reagent. Diphenylcarbazide forms an intense blue color with chromium in the hexavalent state. It has an absorptivity coefficient of about 3400. That means very small amounts of chromium can be detected; 25 micrograms in 25 mL of solution are too dark to read on a spectral device, so concentrations well below that can be detected. Thiocarbazide The sulfur analog is called a thiocarbazide, of which thiocarbohydrazide is the simplest example. Carbazone and thiocarbazone A carbazone is a partially oxidized carbazide with the general formula R=NNH(C=O)NH-NHR. The sulfur analog is called a thiocarbazone, of which dithizone is an example. See also * Semicarbazide * Semicarbazone In organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semicarbazone
In organic chemistry, a semicarbazone is a derivative of imines formed by a condensation reaction between a ketone or aldehyde and semicarbazide. They are classified as imine derivatives because they are formed from the reaction of an aldehyde or ketone with the terminal -NH2 group of semicarbazide, which behaves very similarly to primary amines. Formation ;For ketones :H2NNHC(=O)NH2 + RC(=O)R → R2C=NNHC(=O)NH2 ;For aldehydes :H2NNHC(=O)NH2 + RCHO → RCH=NNHC(=O)NH2 For example, the semicarbazone of acetone would have the structure (CH3)2C=NNHC(=O)NH2. Properties and uses Some semicarbazones, such as nitrofurazone, and thiosemicarbazones are known to have anti-viral and anti-cancer activity, usually mediated through binding to copper or iron in cells. Many semicarbazones are crystalline solids, useful for the identification of the parent aldehydes/ketones by melting point analysis. A ''thiosemicarbazone'' is an analog of a semicarbazone which contains a sulfur atom in pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Group
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis. A functional group is a group of atoms in a molecule with distinctive chemical properties, regardless of the other atoms in the molecule. The atoms in a functional group are linked to each other and to the rest of the molecule by covalent bonds. For repeating units of polymers, functional groups attach to their nonpolar core of carbon atoms and thus add chemical character to carbon chains. Fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condensation Reaction
In organic chemistry, a condensation reaction is a type of chemical reaction in which two molecules are combined to form a single molecule, usually with the loss of a small molecule such as water. If water is lost, the reaction is also known as a dehydration synthesis. However other molecules can also be lost, such as ammonia, ethanol, acetic acid and hydrogen sulfide. The addition of the two molecules typically proceeds in a step-wise fashion to the addition product, usually in equilibrium, and with loss of a water molecule (hence the name condensation). The reaction may otherwise involve the functional groups of the molecule, and is a versatile class of reactions that can occur in acidic or basic conditions or in the presence of a catalyst. This class of reactions is a vital part of life as it is essential to the formation of peptide bonds between amino acids and to the biosynthesis of fatty acids. Many variations of condensation reactions exist. Common examples include the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine hydrate (). Hydrazine is mainly used as a foaming agent in preparing polymer foams, but applications also include its uses as a precursor to polymerization catalysts, pharmaceuticals, and agrochemicals, as well as a long-term storable propellant for in-space spacecraft propulsion. Additionally, hydrazine is used in various rocket fuels and to prepare the gas precursors used in air bags. Hydrazine is used within both nuclear and conventional electrical power plant steam cycles as an oxygen scavenger to control concentrations of dissolved oxygen in an effort to reduce corrosion. the world hydrazine hydrate market amounted to $350 million. About two million tons of hydrazine hydrate were used in foam blowing agents in 2015. Hydrazines r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbohydrazide
Carbohydrazide is the chemical compound with the formula OC(N2H3)2. It is a white, water-soluble solid. It decomposes upon melting. A number of carbazides are known where one or more N-H groups are replaced by other substituents. They occur widely in the drugs, herbicides, plant growth regulators, and dyestuffs. Production Industrially the compound is produced by treatment of urea with hydrazine:Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. . :OC(NH2)2 + 2 N2H4 → OC(N2H3)2 + 2 NH3 It can also be prepared by reactions of other C1-precursors with hydrazine, such as carbonate esters. It can be prepared from phosgene, but this route cogenerates the hydrazinium Hydrazinium is the cation with the formula . This cation has a methylamine-like structure (). It can be derived from hydrazine by protonation (treatment with a strong acid). Hydrazinium is a weak acid with p''K''a = 8.1. Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphenylcarbazide
1,5-Diphenylcarbazide (or simply Diphenylcarbazide, often abbreviated DPC) is a chemical compound from the group of the carbazides. It has a structural formula similar to that of diphenylcarbazone and can be easily converted into it by oxidation. Properties Diphenylcarbazide is a white solid that is scarcely soluble in water, but readily soluble in organic solvents like acetone, hot ethanol and acetic acid. It forms colored complex compounds with certain metal ions. Diphenylcarbazide oxidizes to Diphenylcarbazone when exposed to light and air, turning pink in the process. Uses Diphenylcarbazide is used as a redox indicator and for the photometric determination of certain heavy metal ions, like those of Chromium, Mercury, Cadmium, Osmium, Rubidium, Technetium and more. Reacting a Diphenylcarbazide with Chromium (VI) compounds, such as chromates or dichromates produces diphenylcarbazone, which forms a red-violet complex with the chromium compounds. Chromium (III) compou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar Absorptivity
Molar may refer to: *Molar (tooth), a kind of tooth found in mammals *Molar (grape), another name for the Spanish wine grape Listan Negro *Molar (unit), a unit of concentration equal to 1 mole per litre *Molar mass *Molar volume *El Molar, Tarragona, a village in the comarca (county) of Priorat, province of Tarragona in the autonomous region of Catalonia, Spain *El Molar, Madrid, a town in the north of the Community of Madrid in the road to Burgos, after San Agustín de Guadalix See also * Moler Moler (previously called Snuff) are a power pop band which formed in 1993 as a three-piece with founding mainstays Helen Cattanach on bass guitar and lead vocals and Julien Poulsen on lead guitar. They featured a changing line-up of drummers and ..., a power-pop band from Australia * Moler (surname) {{disambig, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Analog
A structural analog (analogue in modern traditional English; Commonwealth English), also known as a chemical analog or simply an analog, is a compound having a structure similar to that of another compound, but differing from it in respect to a certain component. It can differ in one or more atoms, functional groups, or substructures, which are replaced with other atoms, groups, or substructures. A structural analog can be imagined to be formed, at least theoretically, from the other compound. Structural analogs are often isoelectronic. Despite a high chemical similarity, structural analogs are not necessarily functional analogs and can have very different physical, chemical, biochemical, or pharmacological properties. In drug discovery, either a large series of structural analogs of an initial lead compound are created and tested as part of a structure–activity relationship study or a database is screened for structural analogs of a lead compound. Chemical analogues of il ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiocarbohydrazide
Thiocarbohydrazide is a toxic compound made by the reaction of carbon disulfide with hydrazine (hydrazinolysis). It is used in the silver proteinate specific staining of carbohydrates in electron microscopy An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi .... References {{reflist Hydrazides Thioureas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidized
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogenation, C=C (and other) bonds ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dithizone
Dithizone is a sulfur-containing organic compound. It is a good ligand, and forms complexes with many toxic metals such as lead, thallium and mercury. Dithizone may be prepared by reacting phenylhydrazine with carbon disulfide, followed by reaction with potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which exp .... Dithizone is used to assess the purity of human pancreatic islet preparations used for transplantation into patients with type 1 diabetes. Dithizone binds zinc ions present in the islet's beta cells, and therefore stains the islets red. Exocrine tissue also present in the preparations does not bind dithizone, and is therefore not stained.{{cite journal , last1 = Ricordi , first1 = C , last2 = Gray , first2 = DW , last3 = Hering , first3 = BJ , last4 = Ka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
