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Trityl
Triphenylmethane or triphenyl methane (sometimes also known as Tritan), is the hydrocarbon with the chemical formula, formula (C6H5)3CH. This colorless solid is soluble in nonpolar organic solvents and not in water. Triphenylmethane is the basic skeleton of many synthetic dyes called triarylmethane dyes, many of them are pH indicators, and some display fluorescence. A trityl group in organic chemistry is a triphenylmethyl group Ph3C, e.g. triphenylmethyl chloride (trityl chloride) and the triphenylmethyl radical (trityl radical). Preparation Triphenylmethane was first synthesized in 1872 by the German chemist August Kekulé and his Dutch student Antoine Paul Nicolas Franchimont (1844–1919) by heating diphenylmercury (Hg(C6H5)2, ''Quecksilberdiphenyl'') with benzal chloride (C6H5CHCl2, ''Benzylenchlorid''). Triphenylmethane can be synthesized by Friedel–Crafts reaction from benzene and chloroform with aluminium chloride catalyst: :3 C6H6 + CHCl3 → Ph3CH + 3 HCl Alternatively, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triphenylmethyl Chloride
Triphenylmethyl chloride or trityl chloride (TrCl) is a white solid with the chemical formula C19H15Cl. It is an alkyl halide, sometimes used to introduce the trityl protecting group. Preparation Triphenylmethyl chloride is commercially available. It may be prepared by the reaction of triphenylmethanol with acetyl chloride, or by the Friedel–Crafts alkylation of benzene with carbon tetrachloride to give the trityl chloride-aluminium chloride adduct, which is then hydrolyzed. Reactions Triphenylmethylsodium can be prepared from trityl chloride dissolved in an aprotic solvent and sodium: :(C6H5)3CCl + 2 Na → (C6H5)3CNa + NaCl Reaction with silver hexafluorophosphate gives triphenylmethyl hexafluorophosphate. Trityl chloride reacts with zinc in nonpolar solvents (e.g. benzene) to form Gomberg's dimer.{{cite journal , last1=Gomberg , first1=M. , title=An Instance of Trivalent Carbon: Triphenylmethyl , journal=Journal of the American Chemical Society , date=1900 , volum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzylidene Chloride
Benzal chloride is an organic compound with the formula C6H5CHCl2. This colourless liquid is a lachrymator and is used as a building block in organic synthesis. Preparation and usage Benzal chloride is produced by the free radical chlorination of toluene, being preceded in the process by benzyl chloride (C6H5CH2Cl) and followed by benzotrichloride (C6H5CCl3): : C6H5CH3 + Cl2 → C6H5CH2Cl + HCl : C6H5CH2Cl + Cl2 → C6H5CHCl2 + HCl : C6H5CHCl2 + Cl2 → C6H5CCl3 + HCl Benzylic halides are typically strong alkylating agents, and for this reason benzal chloride is treated as a hazardous compound. Treatment of benzal chloride with sodium gives stilbene. Most benzal chloride main industrial use is as a precursor to benzaldehyde. This conversion involves hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. It is a common element in the universe, estimated at Abundance of the chemical elements, seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element chemical bond, bond to form N2, a colourless and odourless diatomic molecule, diatomic gas. N2 forms about 78% of Atmosphere of Earth, Earth's atmosphere, making it the most abundant chemical species in air. Because of the volatility of nitrogen compounds, nitrogen is relatively rare in the solid parts of the Earth. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772 and independently by Carl Wilhelm Scheele and Henry Cavendish at about the same time. The name was suggested by French chemist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromocresol Green
Bromocresol green (BCG) is a dye of the triphenylmethane family ( triarylmethane dyes). It belongs to a class of dyes called sulfonephthaleins. It is used as a pH indicator in applications such as growth mediums for microorganisms and titrations. In clinical practise, it is commonly used as a diagnostic technique. The most common use of bromocresol green is to measure serum albumin concentration within mammalian blood samples in possible cases of kidney failure and liver disease. In chemistry, bromocresol green is used in Thin-layer chromatography staining solutions to visualize acidic compounds. Properties In aqueous solution, bromocresol green will ionize to give the monoanionic form (yellow), that further deprotonates at higher pH to give the dianionic form (blue), which is stabilized by resonance: : The acid dissociation constant (p''K''a) of this reaction is 4.8. Tap water is sufficiently basic to give a solution of bromocresol green its characteristic blue-green color. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid–base Titration
An acid–base titration is a method of Quantitative analysis (chemistry), quantitative analysis for determining the concentration of Brønsted–Lowry acid–base theory, Brønsted-Lowry acid or base (titrate) by neutralization reaction, neutralizing it using a solution of known concentration (titrant). A pH indicator is used to monitor the progress of the acid–base reaction and a titration curve can be constructed. This differs from other modern modes of titrations, such as Redox titration, oxidation-reduction titrations, precipitation titrations, & complexometric titrations. Although these types of titrations are also used to determine unknown amounts of substances, these substances vary from ions to metals. Acid–base titration finds extensive applications in various scientific fields, such as pharmaceuticals, environmental monitoring, and quality control in industries. This method's precision and simplicity makes it an important tool in quantitative chemical analysis, con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butyllithium
Butyllithium may refer to one of 5 isomeric organolithium reagents of which 3 are commonly used in chemical synthesis: * ''n''-Butyllithium, abbreviated BuLi or nBuLi * ''sec''-Butyllithium, abbreviated ''sec''-BuLi or sBuLi, has 2 stereoisomers, but is commonly used as racemate * ''tert''-Butyllithium, abbreviated ''tert''-BuLi or tBuLi * Isobutyllithium {{Chemistry index ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-nucleophilic Base
As the name suggests, a non-nucleophilic base is a sterically hindered organic base that is a poor nucleophile. Normal bases are also nucleophiles, but often chemists seek the proton-removing ability of a base without any other functions. Typical non-nucleophilic bases are bulky, such that protons can attach to the basic center but alkylation and complexation is inhibited. Non-nucleophilic bases A variety of amines and nitrogen heterocycles are useful bases of moderate strength (pKa of conjugate acid around 10-13) * ''N'',''N''-Diisopropylethylamine (DIPEA, also called Hünig's Base), pKa = 10.75 *1,8-Diazabicycloundec-7-ene (DBU) - useful for E2 elimination reactions, pKa = 13.5 * 1,5-Diazabicyclo(4.3.0)non-5-ene (DBN) - comparable to DBU * 2,6-Di-tert-butylpyridine, a weak non-nucleophilic base pKa = 3.58 * Phosphazene bases, such as ''t''-Bu-P4''Activation in anionic polymerization: Why phosphazene bases are very exciting promoters'' S. Boileau, N. Illy Prog. Polym. Sci., 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Ether
In organic chemistry, crown ethers are cyclic chemical compounds that consist of a ring containing several ether groups (). The most common crown ethers are cyclic oligomers of ethylene oxide, the repeating unit being ethyleneoxy, i.e., . Important members of this series are the tetramer (''n'' = 4), the pentamer (''n'' = 5), and the hexamer (''n'' = 6). The term "crown" refers to the resemblance between the structure of a crown ether bound to a cation, and a crown sitting on a person's head. The first number in a crown ether's name refers to the number of atoms in the cycle, and the second number refers to the number of those atoms that are oxygen. Crown ethers are much broader than the oligomers of ethylene oxide; an important group are derived from catechol. Crown ethers strongly bind certain cations, forming complexes. The oxygen atoms are well situated to coordinate with a cation located at the interior of the ring, whereas the exterior of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphenylmethane
Diphenylmethane is an organic compound with the formula (C6H5)2CH2 (often abbreviated ). The compound consists of methane wherein two hydrogen atoms are replaced by two phenyl groups. It is a white solid. Diphenylmethane is a common skeleton in organic chemistry. The diphenylmethyl group is also known as ''benzhydryl''. Synthesis It is prepared by the Friedel–Crafts alkylation of benzyl chloride with benzene in the presence of a Lewis acid such as aluminium chloride: :C6H5CH2Cl + C6H6 → (C6H5)2CH2 + HCl Reactivity of the C-H bond The methylene group in diphenylmethane is mildly acidic with a p''K''a of 32.2, and so can be deprotonated with sodium amide. :(C6H5)2CH2 + NaNH2− → (C6H5)2CHNa + NH3 The resulting carbanion can be alkylated. For example, treatment with ''n''-bromobutane produces 1,1-diphenylpentane in 92% yield. :(C6H5)2CH− + CH3CH2CH2CH2Br → (C6H5)2CHCH2CH2CH2CH3 + Br− Alkylation of various benzhydryl compounds has been demonstrated us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
