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Dicarbonyl
In organic chemistry, a dicarbonyl is a molecule containing two carbonyl () groups. Although this term could refer to any organic compound containing two carbonyl groups, it is used more specifically to describe molecules in which both carbonyls are in close enough proximity that their reactivity is changed, such as 1,2-, 1,3-, and 1,4-dicarbonyls. Their properties often differ from those of monocarbonyls, and so they are usually considered functional groups of their own. These compounds can have symmetrical or unsymmetrical substituents on each carbonyl, and may also be functionally symmetrical (dialdehydes, di ketones, diesters, ''etc.'') or unsymmetrical (keto-esters, keto-acids, ''etc.''). 1,2-Dicarbonyls 1,2-Dialdehyde The only 1,2-dialdehyde is glyoxal, . Like many alkyldialdehydes, glyoxal is encountered almost exclusively as its hydrate and oligomers thereof. These derivatives often behave equivalently to the aldehydes since hydration is reversible. Glyoxal condenses r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicarbonyl Structure
In organic chemistry, a dicarbonyl is a molecule containing two carbonyl () Functional group, groups. Although this term could refer to any organic compound containing two carbonyl groups, it is used more specifically to describe molecules in which both carbonyls are in close enough proximity that their Reactivity (chemistry), reactivity is changed, such as 1,2-, 1,3-, and 1,4-dicarbonyls. Their properties often differ from those of monocarbonyls, and so they are usually considered functional groups of their own. These compounds can have symmetrical or unsymmetrical substituents on each carbonyl, and may also be functionally symmetrical (dialdehydes, diketones, diesters, ''etc.'') or unsymmetrical (keto-esters, keto-acids, ''etc.''). 1,2-Dicarbonyls 1,2-Dialdehyde The only 1,2-dialdehyde is glyoxal, . Like many alkyldialdehydes, glyoxal is encountered almost exclusively as its hydrate and oligomers thereof. These derivatives often behave equivalently to the aldehydes since hydra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonyl
In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a carbonyl group is often referred to as a carbonyl compound. The term carbonyl can also refer to carbon monoxide as a ligand in an inorganic or organometallic complex (a metal carbonyl, e.g. nickel carbonyl). The remainder of this article concerns itself with the organic chemistry definition of carbonyl, where carbon and oxygen share a double bond. Carbonyl compounds In organic chemistry, a carbonyl group characterizes the following types of compounds: Other organic carbonyls are urea and the carbamates, the derivatives of acyl chlorides chloroformates and phosgene, carbonate esters, thioesters, lactones, lactams, hydroxamates, and isocyanates. Examples of inorganic carbonyl compounds are carbon dioxide and carbonyl sulfide. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enol
In organic chemistry, alkenols (shortened to enols) are a type of reactive structure or intermediate in organic chemistry that is represented as an alkene ( olefin) with a hydroxyl group attached to one end of the alkene double bond (). The terms ''enol'' and ''alkenol'' are portmanteaus deriving from "-ene"/"alkene" and the "-ol" suffix indicating the hydroxyl group of alcohols, dropping the terminal "-e" of the first term. Generation of enols often involves removal of a hydrogen adjacent (α-) to the carbonyl group—i.e., deprotonation, its removal as a proton, . When this proton is not returned at the end of the stepwise process, the result is an anion termed an enolate (see images at right). The enolate structures shown are schematic; a more modern representation considers the molecular orbitals that are formed and occupied by electrons in the enolate. Similarly, generation of the enol often is accompanied by "trapping" or masking of the hydroxy group as an ether, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketone
In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' is methyl), with the formula . Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids (e.g., testosterone), and the solvent acetone. Nomenclature and etymology The word ''ketone'' is derived from ''Aketon'', an old German word for ''acetone''. According to the rules of IUPAC nomenclature, ketone names are derived by changing the suffix ''-ane'' of the parent alkane to ''-anone''. Typically, the position of the carbonyl group is denoted by a number, but traditional nonsystematic names are still generally used for the most important ketones, for example acetone and benzophenone. These nonsystematic names are considere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiourea
Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), except that the oxygen atom is replaced by a sulfur atom (as implied by the ''thio-'' prefix); however, the properties of urea and thiourea differ significantly. Thiourea is a reagent in organic synthesis. "Thioureas" refer to a broad class of compounds with the general structure . Thioureas are related to thioamides, e.g. , where R is methyl, ethyl, etc. Structure and bonding Thiourea is a planar molecule. The C=S bond distance is 1.71 Å. The C-N distances average 1.33 Å. The weakening of the C-S bond by C-N pi-bonding is indicated by the short C=S bond in thiobenzophenone, which is 1.63 Å. Thiourea occurs in two tautomeric forms, of which the thione form predominates in aqueous solutions. The equilibrium constant has been calculated as ''K''eq is . The thiol form, which is also known as an isothiourea, can be encountered in substituted compounds such as i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diol
A diol is a chemical compound containing two hydroxyl groups ( groups). An aliphatic diol is also called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified. 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 dimeric and oligomeric derivatives. This reaction applies to glyoxal and related aldehydes. Vicinal diols In a vicinal diol, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamine
A diamine is an amine with exactly two amino groups. Diamines are used as monomers to prepare polyamides, polyimides, and polyureas. The term ''diamine'' refers mostly to primary diamines, as those are the most reactive. In terms of quantities produced, 1,6-diaminohexane (a precursor to Nylon 6-6) is most important, followed by ethylenediamine. Vicinal diamines (1,2-diamines) are a structural motif in many biological compounds and are used as ligands in coordination chemistry. Aliphatic diamines Linear * 1 carbon: methylenediamine (diaminomethane) of theoretical interest only * 2 carbons: ethylenediamine (1,2-diaminoethane). Related derivatives include the N-alkylated compounds, 1,1-dimethylethylenediamine, 1,2-dimethylethylenediamine, ethambutol, tetrakis(dimethylamino)ethylene, TMEDA. File:Ethylene_diamine.png, Ethylenediamine * 3 carbons: 1,3-diaminopropane (propane-1,3-diamine) * 4 carbons: putrescine (butane-1,4-diamine) * 5 carbons: cadaverine (pentane-1,5-diamine) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxalic Acid
Oxalic acid is an organic acid with the systematic name ethanedioic acid and formula . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name comes from the fact that early investigators isolated oxalic acid from flowering plants of the genus ''Oxalis'', commonly known as wood-sorrels. It occurs naturally in many foods. Excessive ingestion of oxalic acid or prolonged skin contact can be dangerous. Oxalic acid has much greater acid strength than acetic acid. It is a reducing agent and its conjugate base, known as oxalate (), is a chelating agent for metal cations. Typically, oxalic acid occurs as the dihydrate with the formula . History The preparation of salts of oxalic acid (crab acid) from plants had been known, at least since 1745, when the Dutch botanist and physician Herman Boerhaave isolated a salt from wood sorrel. By 1773, François Pierre Savary of Fribourg, Switzerland had isolated oxalic acid from i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-quinone
1,2-Benzoquinone, also called ''ortho''-benzoquinone, is an organic compound with formula . It is one of the two isomers of quinone, the other being 1,4-Benzoquinone, 1,4-benzoquinone. It is a red volatile solid that is soluble in water and ethyl ether. It is rarely encountered because of its instability, but it is of fundamental interest as the parent compound of many derivative (chemistry), derivatives which are known. Structure The molecule has C symmetry. X-ray crystallography shows that the double bonds are localized, with alternatingly long and short C-C distances within the ring. The C=O distances of 1.21 Å are characteristic of ketones. Preparation and occurrence 1,2-Benzoquinone is produced on oxidation of catechol exposed to air in aqueous solution or by ortho oxidation of a phenol. It is a precursor to melanin. A strain of the bacterium ''Pseudomonas mendocina'' metabolism, metabolises benzoic acid, yielding 1,2-benzoquinone via catechol. References {{D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Cyclopentanedione
1,2-Cyclopentanedione is the organic compound with the formula (CH2)3(CO)2. It is one of two isomeric cyclopentanediones, the other being 1,3-cyclopentanedione. It was first prepared by base-induced condensation of di ethylglutarate with diethyloxalate, followed by hydrolysis of the resulting diketodiester followed by decarboxylation. The enol is predicted to be about 1-3 kcal/mol more stable than the diketo form. The enol structure has been confirmed by X-ray crystallography X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles .... Structurally related to 1,2-cyclopentanedione is 2-hydroxy-3-methyl-2-cyclopenten-1-one is a flavor additive, also called cyclotene. References {{DEFAULTSORT:Cyclopentanedione, 1, 2- Diketones Cyclic ketones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Cyclohexanedione
1,2-Cyclohexanedione is an organic compound with the formula (CH)(CO). It is one of three isomeric cyclohexanediones. It is a colorless compound that is soluble in a variety of organic solvents. It can be prepared by oxidation of cyclohexanone by selenium dioxide. The enol is about 1 kcal/mol more stable than the diketo form. Numerous diimine and dioxime ligands have been prepared from this diketone. It condenses with 1,2-diamine A diamine is an amine with exactly two amino groups. Diamines are used as monomers to prepare polyamides, polyimides, and polyureas. The term ''diamine'' refers mostly to primary diamines, as those are the most reactive. In terms of quantities p ...s to give diaza heterocycles. References {{DEFAULTSORT:Cyclohexanedione, 1, 2- Diketones Cyclic ketones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
