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Zinin Reaction
Zinin reaction or Zinin reduction was discovered by a Russian organic chemist Nikolay Zinin (Russian: Николай Николаевич Зинин) (25 August 1812, Shusha – 18 February 1880, Saint Petersburg). This reaction involves conversion of nitro aromatic compounds like nitrobenzene to amines by reduction with sodium sulfides. The reaction exhibits excellent selectivity for the nitro group and is useful in cases where other easily reduced functional groups (e.g., aryl halides and C=C bonds) are present in the molecule. Moreover, dinitrobenzenes can often be reduced selectively to the nitroaniline. Reaction mechanism The precise details of the reaction mechanism remain obscure, but a basic outline is known. The stoichiometry Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions. Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nikolay Zinin
Nikolay Nikolaevich Zinin (russian: link=no, Никола́й Никола́евич Зи́нин; 25 August 1812, in Shusha – 18 February 1880, in Saint Petersburg) was a Russian organic chemist. Life He studied at the University of Kazan where he graduated in mathematics but he started teaching chemistry in 1835. To improve his skills he was asked to study in Europe for some time, which he did between 1838 and 1841. He studied with Justus Liebig in Giessen, where he finished his research on the benzoin condensation, which was discovered by Liebig several years before. He presented his research results at the University of Saint Petersburg, where he received his Ph.D. He became Professor for Chemistry in the same year at the University of Kazan and left for the University of Saint Petersburg in 1847 where he also became a member of the St. Petersburg Academy of Sciences and first president of the Russian Physical and Chemical Society (1868–1877). In St. Petersburg, professor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Reactions
Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, photochemical reactions and redox reactions. In organic synthesis, organic reactions are used in the construction of new organic molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on organic reactions. The oldest organic reactions are combustion of organic fuels and saponification of fats to make soap. Modern organic chemistry starts with the Wöhler synthesis in 1828. In the history of the Nobel Prize in Chemistry awards have been given for the invention of specific organic reactions such as the Grignard reaction in 1912, the Diels-Alder reaction in 1950, the Wittig reaction in 1979 and olefin metathesis in 2005. Classifications Organic chemistry has a strong tradition of naming a specific reac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitro Compound
In organic chemistry, nitro compounds are organic compounds that contain one or more nitro functional groups (). The nitro group is one of the most common explosophores (functional group that makes a compound explosive) used globally. The nitro group is also strongly electron-withdrawing. Because of this property, bonds alpha (adjacent) to the nitro group can be acidic. For similar reasons, the presence of nitro groups in aromatic compounds retards electrophilic aromatic substitution but facilitates nucleophilic aromatic substitution. Nitro groups are rarely found in nature. They are almost invariably produced by nitration reactions starting with nitric acid. Synthesis Preparation of aromatic nitro compounds Aromatic nitro compounds are typically synthesized by nitration. Nitration is achieved using a mixture of nitric acid and sulfuric acid, which produce the nitronium ion (), which is the electrophile: + The nitration product produced on the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrobenzene
Nitrobenzene is an organic compound 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. 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 electrophilic aromatic substitution reaction of it with benzene. The nitronium ion is generated by the reaction of nitric aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group (these may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines). Important amines include amino acids, biogenic amines, trimethylamine, and aniline; Inorganic derivatives of ammonia are also called amines, such as monochloramine (). The substituent is called an amino group. Compounds with a nitrogen atom attached to a carbonyl group, thus having the structure , are called amides and have different chemical properties from amines. Classification of amines Amines can be classified according to the nature and number of substituents on nitrogen. Aliphatic amines contain only H and alkyl substituents. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide
Sulfide (British English also sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to chemical compounds large families of inorganic and organic compounds, e.g. lead sulfide and dimethyl sulfide. Hydrogen sulfide (H2S) and bisulfide (SH−) are the conjugate acids of sulfide. Chemical properties The sulfide ion, S2−, does not exist in aqueous alkaline solutions of Na2S. Instead sulfide converts to hydrosulfide: :S2− + H2O → SH− + OH− Upon treatment with an acid, sulfide salts convert to hydrogen sulfide: :S2− + H+ → SH− :SH− + H+ → H2S Oxidation of sulfide is a complicated process. Depending on the conditions, the oxidation can produce elemental sulfur, polysulfides, polythionates, sulfite, or sulfate. Metal sulfides react with halogens, forming sulfur and metal salts. :8 MgS + 8 I2 → S8 + 8 M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Für Praktische Chemie
A journal, from the Old French ''journal'' (meaning "daily"), may refer to: *Bullet journal, a method of personal organization *Diary, a record of what happened over the course of a day or other period *Daybook, also known as a general journal, a daily record of financial transactions *Logbook, a record of events important to the operation of a vehicle, facility, or otherwise *Record (other) *Transaction log, a chronological record of data processing *Travel journal In publishing, ''journal'' can refer to various periodicals or serials: *Academic journal, an academic or scholarly periodical **Scientific journal, an academic journal focusing on science **Medical journal, an academic journal focusing on medicine **Law review, a professional journal focusing on legal interpretation *Magazine, non-academic or scholarly periodicals in general **Trade magazine, a magazine of interest to those of a particular profession or trade **Literary magazine, a magazine devoted to literat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Willstätter
Richard Martin Willstätter FRS(For) HFRSE (, 13 August 1872 – 3 August 1942) was a German organic chemist whose study of the structure of plant pigments, chlorophyll included, won him the 1915 Nobel Prize for Chemistry. Willstätter invented paper chromatography independently of Mikhail Tsvet. Life Willstätter was born into a Jewish family in Karlsruhe. He was the son of Maxwell (Max) Willstätter, a textile merchant, and his wife, Sophie Ulmann. He went to school at the Karlsruhe Gymnasium and, when his family moved to Nuremberg, he attended the Technical School there. At age 18 he entered the University of Munich to study science and stayed for the next fifteen years. He was in the Department of Chemistry, first as a student of Alfred Einhorn—he received his doctorate in 1894 – then as a faculty member. His doctoral thesis was on the structure of cocaine. Willstätter continued his research into other alkaloids and synthesized several of them. In 1896 he was named Lec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berichte Der Deutschen Chemischen Gesellschaft
''Chemische Berichte'' (usually abbreviated as ''Ber.'' or ''Chem. Ber.'') was a German-language scientific journal of all disciplines of chemistry founded in 1868. It was one of the oldest scientific journals in chemistry, until it merged with ''Recueil des Travaux Chimiques des Pays-Bas'' to form ''Chemische Berichte/Recueil'' in 1997. ''Chemische Berichte/Recueil'' was then merged with other European journals in 1998 to form ''European Journal of Inorganic Chemistry''. History Founded in 1868 as ''Berichte der Deutschen Chemischen Gesellschaft'' (, CODEN BDCGAS), it operated under this title until 1928 (Vol. 61). The journal was then split into: * ''Berichte der Deutschen Chemischen Gesellschaft, A: Vereins-Nachrichten'' (, CODEN BDCAAS), and * ''Berichte der Deutschen Chemischen Gesellschaft, B: Abhandlungen'' (, CODEN BDCBAD). Vol. 78 and 79 (1945–1946) were omitted and not published due to World War II. The journal was renamed ''Chemische Berichte'' (, CODEN CHBEAM) in 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stoichiometry
Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions. Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equals the total mass of the products, leading to the insight that the relations among quantities of reactants and products typically form a ratio of positive integers. This means that if the amounts of the separate reactants are known, then the amount of the product can be calculated. Conversely, if one reactant has a known quantity and the quantity of the products can be empirically determined, then the amount of the other reactants can also be calculated. This is illustrated in the image here, where the balanced equation is: : Here, one molecule of methane reacts with two molecules of oxygen gas to yield one molecule of carbon dioxide and two molecules of water. This particular chemical equation is an example of complete combustion. St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyes And Pigments
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber. There are two broad categories of dyes: natural and synthetic; Natural dyes are dyes extracted from plants, Insects, or minerals. The majority of natural dyes are vegetable dyes derived from plant sources such as roots, berries, bark, leaves, and wood, as well as other biological sources like fungi. Synthetic dyes are also referred to as "coal tar dyes" because they are derived from substances that, until recently, could only be extracted from coal tar. A synthetic dye consists of a chromophore and an auxochrome added to a benzene derivative. Both dyes and pigments are colored, because they absorb only some wavelengths of visible light. Dyes are usually soluble in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Reactions
A name reaction is a chemical reaction named after its discoverers or developers. Among the tens of thousands of organic reactions that are known, hundreds of such reactions are well-known enough to be named after people. Well-known examples include the Grignard reaction, the Sabatier reaction, the Wittig reaction, the Claisen condensation, the Friedel-Crafts acylation, and the Diels-Alder reaction. Books have been published devoted exclusively to name reactions;Alfred Hassner, C. Stumer. ''Organic syntheses based on name reactions''. Elsevier, 2002. Li, Jie Jack. ''Name Reactions: A Collection of Detailed Reaction Mechanisms''. Springer, 2003. the Merck Index, a chemical encyclopedia, also includes an appendix on name reactions. As organic chemistry developed during the 20th century, chemists started associating synthetically useful reactions with the names of the discoverers or developers; in many cases, the name is merely a mnemonic. Some cases of reactions that were not reall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
