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Isophthalaldehyde
Isophthalaldehyde is an organic compound with the formula C6H4(CHO)2. It is one of three isomers of benzene di carbaldehyde, a reduced analog of phthalic acid. It is colorless, although commercial samples often appear yellowish. One preparation entails the Sommelet reaction of α,α'-diamino-ortho-xylene. Reactions and use Like many benzaldehydes, isophthalaldehyde forms a variety of Schiff base derivatives. Being bifunctional (having two formyl groups), isophthalaldehyde allows the formation of polymers or covalent organic frameworks upon reaction with di- or triamines.{{cite journal , doi=10.1021/ja902116f , title= Catalyst-free Preparation of Melamine-Based Microporous Polymer Networks through Schiff Base Chemistry , first1= Matthias Georg , last1=Schwab , first2= Birgit , last2= Fassbender , first3= Hans Wolfgang , last3= Spiess , first4= Arne , last4= Thomas , first5= Xinliang , last5= Feng , first6= Klaus , last6= Müllen , journal= J. Am. Chem. Soc. , year= 2009 , volume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phthalaldehyde
Phthalaldehyde (sometimes also ''o''-phthalaldehyde or ''ortho''-phthalaldehyde, OPA) is the chemical compound with the formula C6H4(CHO)2. It is one of three isomers of benzene dicarbaldehyde, related to phthalic acid. This pale yellow solid is a building block in the synthesis of heterocyclic compounds and a reagent in the analysis of amino acids. OPA dissolves in water solution at pH < 11.5. Its solutions degrade upon UV illumination and exposure to air. Synthesis and reactions The compound was first described in 1887 when it was prepared from α,α,α’,α’-tetrachloro- ortho-xylene. A more modern synthesis is similar: the hydrolysis of the related tetrabromo-o-xylene using potassium |
Sommelet Reaction
The Sommelet reaction is an organic reaction in which a benzyl halide is converted to an aldehyde by action of hexamine and water. : One example, thiophene-2-carboxaldehyde is prepared by the reaction of hexamine with 2-chloromethylthiophene. The reaction is formally an oxidation of the carbon. Reaction mechanism and scope The benzyl halide 1 reacts with hexamine to a quaternary ammonium salt 3, each time just alkylating one nitrogen atom. Then the benzylammonium undergoes an acid-catalyzed hydrolysis process. : Depending on the hydrolysis conditions, the hexamine unit might instead break apart, leaving a benzyl amine (the Delépine reaction). The reaction can also be applied to the oxidation of benzylic amines. In this way, ''m''-xylylenediamine can be converted to isophthalaldehyde Isophthalaldehyde is an organic compound with the formula C6H4(CHO)2. It is one of three isomers of benzene di carbaldehyde, a reduced analog of phthalic acid. It is colorless, although c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terephthalaldehyde
Phthalaldehyde (sometimes also ''o''-phthalaldehyde or ''ortho''-phthalaldehyde, OPA) is the chemical compound with the formula C6H4(CHO)2. It is one of three isomers of benzene dicarbaldehyde, related to phthalic acid. This pale yellow solid is a building block in the synthesis of heterocyclic compounds and a reagent in the analysis of amino acids. OPA dissolves in water solution at pH < 11.5. Its solutions degrade upon UV illumination and exposure to air. Synthesis and reactions The compound was first described in 1887 when it was prepared from α,α,α’,α’-tetrachloro- ortho-xylene. A more modern synthesis is similar: the hydrolysis of the related using potassium |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. 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, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Isomerism
In chemistry, a structural isomer (or constitutional isomer in the IUPAC nomenclature) of a compound is another compound whose molecule has the same number of atoms of each element, but with logically distinct bonds between them. The term metamer was formerly used for the same concept. For example, butanol , methyl propyl ether , and diethyl ether have the same molecular formula but are three distinct structural isomers. The concept applies also to polyatomic ions with the same total charge. A classical example is the cyanate ion and the fulminate ion . It is also extended to ionic compounds, so that (for example) ammonium cyanate and urea are considered structural isomers,William F. Bynum, E. Janet Browne, Roy Porter (2014): ''Dictionary of the History of Science''. 530 pages. and so are methylammonium formate and ammonium acetate . Structural isomerism is the most radical type of isomerism. It is opposed to stereoisomerism, in which the atoms and bonding scheme ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldehyde
In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are common and play important roles in the technology and biological spheres. Structure and bonding Aldehydes feature a carbon center that is connected by a double bond to oxygen and a single bond to hydrogen and single bond to a third substituent, which is carbon or, in the case of formaldehyde, hydrogen. The central carbon is often described as being sp2- hybridized. The aldehyde group is somewhat polar. The C=O bond length is about 120-122 picometers. Physical properties and characterization Aldehydes have properties that are diverse and that depend on the remainder of the molecule. Smaller aldehydes are more soluble in water, formaldehyde and acetaldehyde completely so. The volatile aldehydes have pungent odors. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Redox Reaction
Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. In organic chemistry oxidations and reductions are different from ordinary redox reactions, because many reactions carry the name but do not actually involve electron transfer.March Jerry; (1985). Advanced Organic Chemistry reactions, mechanisms and structure (3rd ed.). New York: John Wiley & Sons, inc. Instead the relevant criterion for organic oxidation is gain of oxygen and/or loss of hydrogen, respectively.''Organic Redox Systems: Synthesis, Properties, and Applications'', Tohru Nishinaga 2016 Simple functional groups can be arranged in order of increasing oxidation state. The oxidation numbers are only an approximation: When methane is oxidized to carbon dioxide its oxidation number changes from −4 to +4. Classical reductions include alkene reduction to alkanes and classical oxidations include oxidation of alcohols to aldehydes. In oxidations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phthalic Acid
Phthalic acid is an aromatic dicarboxylic acid, with formula C6H4(CO2H)2. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large scale. Phthalic acid is one of three isomers of benzenedicarboxylic acid, the others being isophthalic acid and terephthalic acid. Production Phthalic acid is produced by the catalytic oxidation of naphthalene or ''ortho-''xylene directly to phthalic anhydride and a subsequent hydrolysis of the anhydride. Phthalic acid was first obtained by French chemist Auguste Laurent in 1836 by oxidizing naphthalene tetrachloride. Believing the resulting substance to be a naphthalene derivative, he named it "naphthalic acid". After the Swiss chemist Jean Charles Galissard de Marignac determined its correct formula, Laurent gave it its present name. Manufacturing methods in the nineteenth century included oxidation of naphthalene tetrachloride with nitric acid, or, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylene
In organic chemistry, xylene or xylol (; IUPAC name: dimethylbenzene) are any of three organic compounds with the formula . They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring; which hydrogens are substituted determines which of three structural isomers results. It is a colorless, flammable, slightly greasy liquid of great industrial value. The mixture is referred to as both xylene and, more precisely, xylenes. Mixed xylenes refers to a mixture of the xylenes plus ethylbenzene. The four compounds have identical empirical formulas . Typically the four compounds are produced together by various catalytic reforming and pyrolysis methods. Occurrence and production Xylenes are an important petrochemical produced by catalytic reforming and also by carbonization, coal carbonisation in the manufacture of coke (fuel), coke fuel. They also occur in crude oil in concentrations of about 0.5–1%, depending on the source. Small quantities occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schiff Base
In organic chemistry, a Schiff base (named after Hugo Schiff) is a compound with the general structure ( = alkyl or aryl, but not hydrogen). They can be considered a sub-class of imines, being either secondary ketimines or secondary aldimines depending on their structure. The term is often synonymous with azomethine which refers specifically to secondary aldimines (i.e. where R' ≠ H). A number of special naming systems exist for these compounds. For instance a Schiff base derived from an aniline, where is a phenyl or a substituted phenyl, can be called an ''anil'', while bis-compounds are often referred to as salen-type compounds. The term Schiff base is normally applied to these compounds when they are being used as ligands to form coordination complexes with metal ions. Such complexes occur naturally, for instance in corrin, but the majority of Schiff bases are artificial and are used to form many important catalysts, such as Jacobsen's catalyst. Synthesis Schiff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bifunctional
In organic chemistry, when a single organic molecule has two different functional groups, it is called a bifunctional molecule . A bifunctional molecule has the properties of two different types of functional groups, such as an alcohol (), amide (), aldehyde (), nitrile () or carboxylic acid (). Many bifunctional molecules are used to produce medicines and catalysts, while others are used in condensation polymerization like polyester and polyamide. In organic molecules, functional groups are atoms or molecules that are responsible for the characteristic properties of that molecule, with the exceptions of double and triple bonds, which are also functional groups. See also * Functionality (chemistry) In chemistry, functionality is the presence of functional groups in a molecule. A monofunctional molecule possesses one functional group, a difunctional two, a trifunctional three, and so forth. In organic chemistry (and other fields of chemis ... References Further reading * Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covalent Organic Framework
Covalent organic frameworks (COFs) are a class of materials that form two- or three-dimensional structures through reactions between organic precursors resulting in strong, covalent bonds to afford porous, stable, and crystalline materials. COFs emerged as a field from the overarching domain of organic materials as researchers optimized both synthetic control and precursor selection. These improvements to coordination chemistry enabled non-porous and amorphous organic materials such as organic polymers to advance into the construction of porous, crystalline materials with rigid structures that granted exceptional material stability in a wide range of solvents and conditions. Through the development of reticular chemistry, precise synthetic control was achieved and resulted in ordered, nano-porous structures with highly preferential structural orientation and properties which could be synergistically enhanced and amplified. With judicious selection of COF secondary building units (SBU ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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