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Armstrong's Acid
Armstrong's acid (naphthalene-1,5-disulfonic acid) is a fluorescent organic compound with the formula C10H6(SO3H)2. It is one of several isomers of naphthalenedisulfonic acid. It a colorless solid, typically obtained as the tetrahydrate. Like other sulfonic acids, it is a strong acid. It is named for British chemist Henry Edward Armstrong. Production and use It is prepared by disulfonation of naphthalene with oleum: :C10H8 + 2 SO3 → C10H6(SO3H)2 Further sulfonation gives The 1,3,5-trisulfonic acid derivative.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. . Reactions and uses Fusion of Armstrong's acid in NaOH gives the disodium salt of 1,5-dihydroxynaphthalene, which can be acidified to give the diol. The intermediate in this hydrolysis, 1-hydroxynaphthalene-5-sulfonic acid, is also useful. Nitration gives nitrodisulfonic acids, which are precursors to amino derivatives. The disodium salt is some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-containing compounds such as alkanes (e.g. methane ) and its derivatives are universally considered organic, but many others are sometimes considered inorganic, such as certain compounds of carbon with nitrogen and oxygen (e.g. cyanide ion , hydrogen cyanide , chloroformic acid , carbon dioxide , and carbonate ion ). Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, and even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the existence or possibility of isomers. Isomers do not necessarily share similar chemical property, chemical or physical property, physical properties. Two main forms of isomerism are structural isomerism, structural (or constitutional) isomerism, in which ''chemical bond, bonds'' between the atoms differ; and stereoisomerism (or spatial isomerism), in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different Isotopologue, isotopologues. The depth of analy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonic Acid
In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is known as a sulfo group. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound (with the organic substituent replaced by hydrogen) is the parent sulfonic acid, , a tautomer of sulfurous acid, . Salt (chemistry), Salts or esters of sulfonic acids are called sulfonates. Preparation Aryl sulfonic acids are produced by the process of sulfonation. Usually the sulfonating agent is sulfur trioxide. A large scale application of this method is the production of alkylbenzenesulfonic acids: : In this reaction, sulfur trioxide is an electrophile and the arene is the nucleophile. The reaction is an example of electrophilic aromatic substitution. In a related process, carboxyli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Edward Armstrong
Henry Edward Armstrong FRS FRSE (Hon) (6 May 1848 – 13 July 1937) was a British chemist. Although Armstrong was active in many areas of scientific research, such as the chemistry of naphthalene derivatives, he is remembered today largely for his ideas and work on the teaching of science. Armstrong's acid is named for him. Life and work Armstrong was born the son of Richard Armstrong, a commission agent and importer, and Mary Ann Biddle. He lived most of his life in Lewisham, a suburb of London. After finishing school in 1864 at age 16, he spent a winter in Gibraltar, with a relative, for health reasons. In the spring of 1865, Armstrong returned to England and entered the Royal College of Chemistry in London, now the department of chemistry at Imperial College. Chemical training in those days was not lengthy, and at the age of 18 he was selected by Edward Frankland to assist in devising methods of determining organic impurities in sewage. Armstrong pursued further studies u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oleum
Oleum (Latin ''oleum'', meaning oil), or fuming sulfuric acid, is a term referring to solutions of various compositions of sulfur trioxide in sulfuric acid, or sometimes more specifically to disulfuric acid (also known as pyrosulfuric acid). Oleums can be described by the formula ''y''SO3·H2O where ''y'' is the total molar mass of sulfur trioxide content. The value of ''y'' can be varied, to include different oleums. They can also be described by the formula H2SO4·''x''SO3 where ''x'' is now defined as the molar free sulfur trioxide content. Oleum is generally assessed according to the free SO3 content by mass. It can also be expressed as a percentage of sulfuric acid strength; for oleum concentrations, that would be over 100%. For example, 10% oleum can also be expressed as H2SO4·''0.13611''SO3, ''1.13611''SO3·H2O or 102.25% sulfuric acid. The conversion between % acid and % oleum is: :\%\,\text = 100 + \frac \times \%\,\text For ''x'' = 1 and ''y'' = 2 the empirical formul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,5-Dihydroxynaphthalene
1,5-Dihydroxynaphthalene is an organic compound with the formula CH(OH). It is one of several isomers of dihydroxynaphthalene. A white solid, degraded samples often appear grey to light brown solid that are soluble in polar organic solvents. It is a precursor to certain dyes. Preparation and use 1,5-Dihydroxynaphthalene is prepared from naphthalene-1,5-disulfonic acid by hydrolysis with strong base followed by acidification. It couples with various aryl diazonium salts to give diazo dyes. Oxidation with chromium trioxide gives juglone, a naturally occurring dye.. In supramolecular chemistry Supramolecular chemistry refers to the branch of chemistry concerning Chemical species, chemical systems composed of a integer, discrete number of molecules. The strength of the forces responsible for spatial organization of the system range from w ..., 1,5-dihydroxynaphthalene is a popular reagent. References {{DEFAULTSORT:Dihydroxynaphthalene, 1, 5- 1-Naphthols Diols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diol
A diol is a chemical compound containing two hydroxyl groups ( groups). An aliphatic diol may also be called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified. They are used as protecting groups of carbonyl groups, making them essential in synthesis of organic chemistry. The most common industrial diol is ethylene glycol. Examples of diols in which the hydroxyl functional groups are more widely separated include 1,4-butanediol and propylene-1,3-diol, or beta propylene glycol, . Synthesis of classes of diols Geminal diols A geminal diol has two hydroxyl groups bonded to the same atom. These species arise by hydration of the carbonyl compounds. The hydration is usually unfavorable, but a notable exception is formaldehyde which, in water, exists in equilibrium with methanediol H2C(OH)2. Another example is (F3C)2C(OH)2, the hydrated form of hexafluoroacetone. Many gem-diols undergo further condensation to give dimer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Divalent
In chemistry, the valence (US spelling) or valency (British spelling) of an atom is a measure of its combining capacity with other atoms when it forms chemical compounds or molecules. Valence is generally understood to be the number of chemical bonds that each atom of a given chemical element typically forms. Double bonds are considered to be two bonds, triple bonds to be three, quadruple bonds to be four, quintuple bonds to be five and sextuple bonds to be six. In most compounds, the valence of hydrogen is 1, of oxygen is 2, of nitrogen is 3, and of carbon is 4. Valence is not to be confused with the related concepts of the coordination number, the oxidation state, or the number of valence electrons for a given atom. Description The valence is the combining capacity of an atom of a given element, determined by the number of hydrogen atoms that it combines with. In methane, carbon has a valence of 4; in ammonia, nitrogen has a valence of 3; in water, oxygen has a valence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counterion
160px, cation-exchange_resin.html" ;"title="Polystyrene sulfonate, a cation-exchange resin">Polystyrene sulfonate, a cation-exchange resin, is typically supplied with as the counterion. In chemistry, a counterion (sometimes written as "counter ion", pronounced as such) is the ion that accompanies an Ionic compound, ionic species in order to maintain Electric charge, electric neutrality. In table salt (NaCl, also known as sodium chloride) the sodium ion (positively charged) is the counterion for the chloride ion (negatively charged) and vice versa. A counterion will be more commonly referred to as an anion or a cation, depending on whether it is negatively or positively charged. Thus, the counterion to an anion will be a cation, and vice versa. In biochemistry, counterions are generally vaguely defined. Depending on their charge, proteins are associated with a variety of smaller anions and cations. In plant cells, the anion malate is often accumulated in the vacuole to decrea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base (chemistry)
In chemistry, there are three definitions in common use of the word "base": '' Arrhenius bases'', '' Brønsted bases'', and '' Lewis bases''. All definitions agree that bases are substances that react with acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...s, as originally proposed by Guillaume-François Rouelle, G.-F. Rouelle in the mid-18th century. In 1884, Svante Arrhenius proposed that a base is a substance which dissociates in aqueous solution to form hydroxide ions OH−. These ions can react with Hydron (chemistry), hydrogen ions (H+ according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction. A base was therefore a metal hydroxide such as NaOH or Calcium hydroxide, Ca(OH)2. Such aqueous hydroxide solutions were also described by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesylate
In organosulfur chemistry, a mesylate is any salt or ester of methanesulfonic acid (). In salts, the mesylate is present as the anion. When modifying the international nonproprietary name of a pharmaceutical substance containing the group or anion, the spelling used is sometimes mesilate (as in ''imatinib mesilate'', the mesylate salt of imatinib). Mesylate esters are a group of organic compounds that share a common functional group with the general structure , abbreviated , where R is an organic substituent. Mesylate is considered a leaving group in nucleophilic substitution reactions. Preparation Mesylate esters are generally prepared by treating an alcohol and methanesulfonyl chloride in the presence of a base, such as triethylamine. Mesyl Related to mesylate is the mesyl (Ms) or methanesulfonyl () functional group. The shortened term itself was coined by Helferich et al. in 1938 similarly to tosyl adopted earlier. Methanesulfonyl chloride is often refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
