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74-554: Adenosine diphosphate ribose ( ADPR ) is an ester molecule formed into chains by the enzyme poly ADP ribose polymerase . ADPR is created from cyclic ADP-ribose (cADPR) by the CD38 enzyme using nicotinamide adenine dinucleotide (NAD) as a cofactor . ADPR binds to and activates the TRPM2 ion channel. ADPR is the most potent agonist of the TRPM2 channel. cADPR also binds to TPRM2, and

148-476: A carbonyl group C=O, which is a divalent group at C atom, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides , carboxylic acid esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than

222-444: A dehydrating agent: The equilibrium constant for such reactions is about 5 for typical esters, e.g., ethyl acetate. The reaction is slow in the absence of a catalyst. Sulfuric acid is a typical catalyst for this reaction. Many other acids are also used such as polymeric sulfonic acids . Since esterification is highly reversible, the yield of the ester can be improved using Le Chatelier's principle : Reagents are known that drive

296-535: A relative static permittivity (dielectric constant) of 6.2, it dissolves not only polar compounds such as inorganic salts and sugars , but also non-polar compounds such as oils as well as polar solutes. It is miscible with polar and non-polar solvents such as water, chloroform , and hexane . With higher alkanes (starting with octane ), acetic acid is not miscible at all compositions, and solubility of acetic acid in alkanes declines with longer n-alkanes. The solvent and miscibility properties of acetic acid make it

370-420: A salt containing this anion, or an ester of acetic acid. (The symbol Ac for the acetyl functional group is not to be confused with the symbol Ac for the element actinium ; context prevents confusion among organic chemists). To better reflect its structure, acetic acid is often written as CH 3 −C(O)OH , CH 3 −C(=O)−OH , CH 3 COOH , and CH 3 CO 2 H . In the context of acid–base reactions ,

444-619: A broad array of plastics , plasticizers , resins , and lacquers , and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties . Esters of phosphoric acid form the backbone of DNA molecules. Esters of nitric acid , such as nitroglycerin , are known for their explosive properties. There are compounds in which an acidic hydrogen of acids mentioned in this article are not replaced by an organyl, but by some other group. According to some authors, those compounds are esters as well, especially when

518-430: A certain extent in pure acetic acid, but are disrupted by hydrogen-bonding solvents. The dissociation enthalpy of the dimer is estimated at 65.0–66.0 kJ/mol, and the dissociation entropy at 154–157 J mol  K . Other carboxylic acids engage in similar intermolecular hydrogen bonding interactions. Liquid acetic acid is a hydrophilic ( polar ) protic solvent , similar to ethanol and water . With

592-955: A combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s -trans (i.e. E ) conformation due to their cyclic structure. Esters derived from carboxylic acids and alcohols are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight. Esters are generally identified by gas chromatography, taking advantage of their volatility. IR spectra for esters feature an intense sharp band in

666-457: A methanol carbonylation pilot plant as early as 1925. However, a lack of practical materials that could contain the corrosive reaction mixture at the high pressures needed (200 atm or more) discouraged commercialization of these routes. The first commercial methanol carbonylation process, which used a cobalt catalyst, was developed by German chemical company BASF in 1963. In 1968, a rhodium -based catalyst ( cis − [Rh(CO) 2 I 2 ] )

740-565: A part of metal and metalloid alkoxides , of which many hundreds are known, could be classified as esters of the corresponding acids (e.g. aluminium triethoxide ( Al(OCH 2 CH 3 ) 3 ) could be classified as an ester of aluminic acid which is aluminium hydroxide , tetraethyl orthosilicate ( Si(OCH 2 CH 3 ) 4 ) could be classified as an ester of orthosilicic acid , and titanium ethoxide ( Ti(OCH 2 CH 3 ) 4 ) could be classified as an ester of orthotitanic acid ). Esters derived from carboxylic acids and alcohols contain

814-513: A sweet substance also called sugar of lead or sugar of Saturn , which contributed to lead poisoning among the Roman aristocracy. In the 16th-century German alchemist Andreas Libavius described the production of acetone from the dry distillation of lead acetate, ketonic decarboxylation . The presence of water in vinegar has such a profound effect on acetic acid's properties that for centuries chemists believed that glacial acetic acid and

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888-563: A useful industrial chemical, for example, as a solvent in the production of dimethyl terephthalate . At physiological pHs, acetic acid is usually fully ionised to acetate in aqueous solution. The acetyl group , formally derived from acetic acid, is fundamental to all forms of life. Typically, it is bound to coenzyme A by acetyl-CoA synthetase enzymes, where it is central to the metabolism of carbohydrates and fats . Unlike longer-chain carboxylic acids (the fatty acids ), acetic acid does not occur in natural triglycerides . Most of

962-405: A warm, airy place will become vinegar over the course of a few months. Industrial vinegar-making methods accelerate this process by improving the supply of oxygen to the bacteria. The first batches of vinegar produced by fermentation probably followed errors in the winemaking process. If must is fermented at too high a temperature, acetobacter will overwhelm the yeast naturally occurring on

1036-684: Is γ-valerolactone . An uncommon class of esters are the orthoesters . One of them are the esters of orthocarboxylic acids. Those esters have the formula RC(OR′) 3 , where R stands for any group (organic or inorganic) and R ′ stands for organyl group. For example, triethyl orthoformate ( HC(OCH 2 CH 3 ) 3 ) is derived, in terms of its name (but not its synthesis) from esterification of orthoformic acid ( HC(OH) 3 ) with ethanol . Esters can also be derived from inorganic acids. Inorganic acids that exist as tautomers form two or more types of esters. Some inorganic acids that are unstable or elusive form stable esters. In principle,

1110-542: Is a dibutylstannylene ester of lauric acid , and the Phillips catalyst CrO 2 (OSi(OCH 3 ) 3 ) 2 is a trimethoxysilyl ester of chromic acid ( H 2 CrO 4 ). The word ester was coined in 1848 by a German chemist Leopold Gmelin , probably as a contraction of the German Essigäther , " acetic ether ". The names of esters that are formed from an alcohol and an acid, are derived from

1184-463: Is also an equilibrium process – essentially the reverse of the Fischer esterification reaction. Because an alcohol (which acts as the leaving group) and water (which acts as the nucleophile) have similar p K a values, the forward and reverse reactions compete with each other. As in transesterification, using a large excess of reactant (water) or removing one of the products (the alcohol) can promote

1258-418: Is an acidic, colourless liquid and organic compound with the chemical formula CH 3 COOH (also written as CH 3 CO 2 H , C 2 H 4 O 2 , or HC 2 H 3 O 2 ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. It has been used, as a component of vinegar, throughout history from at least the third century BC. Acetic acid

1332-446: Is confined to a few niche applications. Acetic acid is a chemical reagent for the production of chemical compounds. The largest single use of acetic acid is in the production of vinyl acetate monomer , closely followed by acetic anhydride and ester production. The volume of acetic acid used in vinegar is comparatively small. The primary use of acetic acid is the production of vinyl acetate monomer (VAM). In 2008, this application

1406-648: Is considered too hazardous and expensive for large-scale applications. Carboxylic acids are esterified by treatment with epoxides , giving β-hydroxyesters: This reaction is employed in the production of vinyl ester resin from acrylic acid . Alcohols react with acyl chlorides and acid anhydrides to give esters: The reactions are irreversible simplifying work-up . Since acyl chlorides and acid anhydrides also react with water, anhydrous conditions are preferred. The analogous acylations of amines to give amides are less sensitive because amines are stronger nucleophiles and react more rapidly than does water. This method

1480-421: Is controlled by the food additive code E260 as an acidity regulator and as a condiment. In biochemistry , the acetyl group , derived from acetic acid, is fundamental to all forms of life. When bound to coenzyme A , it is central to the metabolism of carbohydrates and fats . The global demand for acetic acid as of 2023 is about 17.88 million metric tonnes per year (t/a). Most of the world's acetic acid

1554-605: Is employed only for laboratory-scale procedures, as it is expensive. Trimethyloxonium tetrafluoroborate can be used for esterification of carboxylic acids under conditions where acid-catalyzed reactions are infeasible: Although rarely employed for esterifications, carboxylate salts (often generated in situ ) react with electrophilic alkylating agents , such as alkyl halides , to give esters. Anion availability can inhibit this reaction, which correspondingly benefits from phase transfer catalysts or such highly polar aprotic solvents as DMF . An additional iodide salt may, via

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1628-455: Is made in submerged tank culture , first described in 1949 by Otto Hromatka and Heinrich Ebner. In this method, alcohol is fermented to vinegar in a continuously stirred tank, and oxygen is supplied by bubbling air through the solution. Using modern applications of this method, vinegar of 15% acetic acid can be prepared in only 24 hours in batch process, even 20% in 60-hour fed-batch process. Species of anaerobic bacteria , including members of

1702-516: Is not usually reversible. Hydrazines and hydroxylamine can be used in place of amines. Esters can be converted to isocyanates through intermediate hydroxamic acids in the Lossen rearrangement . Sources of carbon nucleophiles, e.g., Grignard reagents and organolithium compounds, add readily to the carbonyl. Acetic acid Acetic acid / ə ˈ s iː t ɪ k / , systematically named ethanoic acid / ˌ ɛ θ ə ˈ n oʊ ɪ k / ,

1776-603: Is one illustrative example. The carbonylation of methanol yields methyl formate , which is the main commercial source of formic acid . The reaction is catalyzed by sodium methoxide : In hydroesterification , alkenes and alkynes insert into the O−H bond of carboxylic acids. Vinyl acetate is produced industrially by the addition of acetic acid to acetylene in the presence of zinc acetate catalysts: Vinyl acetate can also be produced by palladium -catalyzed reaction of ethylene, acetic acid , and oxygen : Silicotungstic acid

1850-455: Is produced via the carbonylation of methanol . Its production and subsequent industrial use poses health hazards to workers, including incidental skin damage and chronic respiratory injuries from inhalation. The trivial name "acetic acid" is the most commonly used and preferred IUPAC name . The systematic name "ethanoic acid", a valid IUPAC name, is constructed according to the substitutive nomenclature. The name "acetic acid" derives from

1924-618: Is promoted by iridium for greater efficiency. Known as the Cativa process , the iridium -catalyzed production of glacial acetic acid is greener , and has largely supplanted the Monsanto process, often in the same production plants. Interstellar acetic acid was discovered in 1996 by a team led by David Mehringer using the former Berkeley-Illinois-Maryland Association array at the Hat Creek Radio Observatory and

1998-464: Is the substitution reaction between a carboxylic acid ( R−C(=O)−OH ) and an alcohol ( R'−OH ), forming an ester ( R−C(=O)−O−R' ), where R stands for any group (typically hydrogen or organyl) and R ′ stands for organyl group. Organyl esters of carboxylic acids typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones . They perform as high-grade solvents for

2072-408: Is the second simplest carboxylic acid (after formic acid ). It is an important chemical reagent and industrial chemical across various fields, used primarily in the production of cellulose acetate for photographic film , polyvinyl acetate for wood glue , and synthetic fibres and fabrics. In households, diluted acetic acid is often used in descaling agents . In the food industry , acetic acid

2146-608: Is thought to be competitive with methanol carbonylation for smaller plants (100–250 kt/a), depending on the local price of ethylene. For most of human history, acetic acid bacteria of the genus Acetobacter have made acetic acid, in the form of vinegar. Given sufficient oxygen, these bacteria can produce vinegar from a variety of alcoholic foodstuffs. Commonly used feeds include apple cider , wine , and fermented grain , malt , rice , or potato mashes. The overall chemical reaction facilitated by these bacteria is: A dilute alcohol solution inoculated with Acetobacter and kept in

2220-504: Is used as an acyl-transfer catalyst . Another method for the dehydration of mixtures of alcohols and carboxylic acids is the Mitsunobu reaction : Carboxylic acids can be esterified using diazomethane : Using this diazomethane, mixtures of carboxylic acids can be converted to their methyl esters in near quantitative yields, e.g., for analysis by gas chromatography . The method is useful in specialized organic synthetic operations but

2294-495: Is used in the production of ethyl acetate from acetaldehyde . Esters are less reactive than acid halides and anhydrides. As with more reactive acyl derivatives, they can react with ammonia and primary and secondary amines to give amides, although this type of reaction is not often used, since acid halides give better yields. Esters can be converted to other esters in a process known as transesterification . Transesterification can be either acid- or base-catalyzed, and involves

Adenosine diphosphate ribose - Misplaced Pages Continue

2368-411: Is used to manufacture ethyl acetate by the alkylation of acetic acid by ethylene: The Tishchenko reaction involves disproportionation of an aldehyde in the presence of an anhydrous base to give an ester. Catalysts are aluminium alkoxides or sodium alkoxides. Benzaldehyde reacts with sodium benzyloxide (generated from sodium and benzyl alcohol ) to generate benzyl benzoate . The method

2442-506: The Finkelstein reaction , catalyze the reaction of a recalcitrant alkyl halide. Alternatively, salts of a coordinating metal, such as silver, may improve the reaction rate by easing halide elimination. Transesterification , which involves changing one ester into another one, is widely practiced: Like the hydrolysation, transesterification is catalysed by acids and bases. The reaction is widely used for degrading triglycerides , e.g. in

2516-550: The Latin word for vinegar , " acetum ", which is related to the word " acid " itself. "Glacial acetic acid" is a name for water-free ( anhydrous ) acetic acid. Similar to the German name "Eisessig" ("ice vinegar"), the name comes from the solid ice-like crystals that form with agitation, slightly below room temperature at 16.6 °C (61.9 °F). Acetic acid can never be truly water-free in an atmosphere that contains water, so

2590-512: The Wacker process , and then oxidised as above. In more recent times, chemical company Showa Denko , which opened an ethylene oxidation plant in Ōita , Japan, in 1997, commercialised a cheaper single-stage conversion of ethylene to acetic acid. The process is catalyzed by a palladium metal catalyst supported on a heteropoly acid such as silicotungstic acid . A similar process uses the same metal catalyst on silicotungstic acid and silica: It

2664-413: The grapes . As the demand for vinegar for culinary, medical, and sanitary purposes increased, vintners quickly learned to use other organic materials to produce vinegar in the hot summer months before the grapes were ripe and ready for processing into wine. This method was slow, however, and not always successful, as the vintners did not understand the process. One of the first modern commercial processes

2738-447: The naphthenate salts of manganese , cobalt , and chromium . The typical reaction is conducted at temperatures and pressures designed to be as hot as possible while still keeping the butane a liquid. Typical reaction conditions are 150 °C (302 °F) and 55 atm. Side-products may also form, including butanone , ethyl acetate , formic acid , and propionic acid . These side-products are also commercially valuable, and

2812-573: The organyl parts of the carboxylic acid and the alcohol, respectively, and R can be a hydrogen in the case of esters of formic acid . For example, butyl acetate (systematically butyl ethanoate), derived from butanol and acetic acid (systematically ethanoic acid) would be written CH 3 CO 2 (CH 2 ) 3 CH 3 . Alternative presentations are common including BuOAc and CH 3 COO(CH 2 ) 3 CH 3 . Cyclic esters are called lactones , regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone

2886-400: The reaction product . Esters are common in organic chemistry and biological materials, and often have a pleasant characteristic, fruity odor. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers . The classic synthesis is the Fischer esterification , which involves treating a carboxylic acid with an alcohol in the presence of

2960-485: The abbreviation HAc is sometimes used, where Ac in this case is a symbol for acetate (rather than acetyl). The carboxymethyl functional group derived from removing one hydrogen from the methyl group of acetic acid has the chemical formula −CH 2 −C(=O)−OH . Vinegar was known early in civilization as the natural result of exposure of beer and wine to air because acetic acid-producing bacteria are present globally. The use of acetic acid in alchemy extends into

3034-405: The acetate generated in cells for use in acetyl-CoA is synthesized directly from ethanol or pyruvate . However, the artificial triglyceride triacetin (glycerine triacetate) is a common food additive and is found in cosmetics and topical medicines; this additive is metabolized to glycerol and acetic acid in the body. Acetic acid is produced and excreted by acetic acid bacteria , notably

Adenosine diphosphate ribose - Misplaced Pages Continue

3108-507: The acetic acid will precipitate out. As of 2003–2005, total worldwide production of virgin acetic acid was estimated at 5 Mt/a (million tonnes per year), approximately half of which was produced in the United States. European production was approximately 1 Mt/a and declining, while Japanese production was 0.7 Mt/a. Another 1.5 Mt were recycled each year, bringing the total world market to 6.5 Mt/a. Since then,

3182-524: The acid found in vinegar were two different substances. French chemist Pierre Adet proved them identical. In 1845 German chemist Hermann Kolbe synthesised acetic acid from inorganic compounds for the first time. This reaction sequence consisted of chlorination of carbon disulfide to carbon tetrachloride , followed by pyrolysis to tetrachloroethylene and aqueous chlorination to trichloroacetic acid , and concluded with electrolytic reduction to acetic acid. By 1910, most glacial acetic acid

3256-567: The action of both molecules is synergistic , with both molecules enhancing the action of the other molecule in activating the TRPM2 channel. Researchers are not sure how the Adenosine diphosphate reacts with the TRPM2 channel, but the ribose sugar may play a role in activating the TRPM2 ion channel. This biochemistry article is a stub . You can help Misplaced Pages by expanding it . Ester Glycerides are fatty acid esters of glycerol ; they are important in biology, being one of

3330-427: The aroma of many fruits, including apples , durians , pears , bananas , pineapples , and strawberries . Several billion kilograms of polyesters are produced industrially annually, important products being polyethylene terephthalate , acrylate esters , and cellulose acetate . Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as

3404-576: The chemical industry is made by the carbonylation of methanol , explained below. The biological route accounts for only about 10% of world production, but it remains important for the production of vinegar because many food purity laws require vinegar used in foods to be of biological origin. Other processes are methyl formate isomerization, conversion of syngas to acetic acid, and gas phase oxidation of ethylene and ethanol . Acetic acid can be purified via fractional freezing using an ice bath. The water and other impurities will remain liquid while

3478-439: The concentration of domestic vinegar) has a pH of 2.4, indicating that merely 0.4% of the acetic acid molecules are dissociated. [REDACTED] In solid acetic acid, the molecules form chains of individual molecules interconnected by hydrogen bonds . In the vapour phase at 120 °C (248 °F), dimers can be detected. Dimers also occur in the liquid phase in dilute solutions with non-hydrogen-bonding solvents, and to

3552-420: The corresponding amides . The p K a of the alpha-hydrogens on esters of carboxylic acids is around 25 (alpha-hydrogen is a hydrogen bound to the carbon adjacent to the carbonyl group (C=O) of carboxylate esters). Many carboxylic acid esters have the potential for conformational isomerism , but they tend to adopt an S - cis (or Z ) conformation rather than the S - trans (or E ) alternative, due to

3626-465: The dehydration of mixtures of alcohols and carboxylic acids. One example is the Steglich esterification , which is a method of forming esters under mild conditions. The method is popular in peptide synthesis , where the substrates are sensitive to harsh conditions like high heat. DCC ( dicyclohexylcarbodiimide ) is used to activate the carboxylic acid to further reaction. 4-Dimethylaminopyridine (DMAP)

3700-423: The detections. The hydrogen centre in the carboxyl group (−COOH) in carboxylic acids such as acetic acid can separate from the molecule by ionization: Because of this release of the proton ( H ), acetic acid has acidic character. Acetic acid is a weak monoprotic acid . In aqueous solution, it has a pK a value of 4.76. Its conjugate base is acetate ( CH 3 COO ). A 1.0  M solution (about

3774-399: The equation: The process involves iodomethane as an intermediate, and occurs in three steps. A metal carbonyl catalyst is needed for the carbonylation (step 2). Two related processes exist for the carbonylation of methanol: the rhodium-catalyzed Monsanto process , and the iridium-catalyzed Cativa process . The latter process is greener and more efficient and has largely supplanted

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3848-408: The first carbon atom of the organyl group replacing acidic hydrogen, is replaced by another atom from the group 14 elements ( Si , Ge , Sn , Pb ); for example, according to them, trimethylstannyl acetate (or trimethyltin acetate) CH 3 COOSn(CH 3 ) 3 is a trimethylstannyl ester of acetic acid , and dibutyltin dilaurate (CH 3 (CH 2 ) 10 COO) 2 Sn((CH 2 ) 3 CH 3 ) 2

3922-745: The former Millimeter Array located at the Owens Valley Radio Observatory . It was first detected in the Sagittarius B2 North molecular cloud (also known as the Sgr B2 Large Molecule Heimat source). Acetic acid has the distinction of being the first molecule discovered in the interstellar medium using solely radio interferometers ; in all previous ISM molecular discoveries made in the millimetre and centimetre wavelength regimes, single dish radio telescopes were at least partly responsible for

3996-496: The former process. Catalytic amounts of water are used in both processes, but the Cativa process requires less, so the water-gas shift reaction is suppressed, and fewer by-products are formed. By altering the process conditions, acetic anhydride may also be produced in plants using rhodium catalysis. Prior to the commercialization of the Monsanto process, most acetic acid was produced by oxidation of acetaldehyde . This remains

4070-495: The forward reaction. Basic hydrolysis of esters, known as saponification , is not an equilibrium process; a full equivalent of base is consumed in the reaction, which produces one equivalent of alcohol and one equivalent of a carboxylate salt. The saponification of esters of fatty acids is an industrially important process, used in the production of soap. Esterification is a reversible reaction. Esters undergo hydrolysis under acidic and basic conditions. Under acidic conditions,

4144-494: The genus Acetobacter and Clostridium acetobutylicum . These bacteria are found universally in foodstuffs , water , and soil , and acetic acid is produced naturally as fruits and other foods spoil. Acetic acid is also a component of the vaginal lubrication of humans and other primates , where it appears to serve as a mild antibacterial agent. Acetic acid is produced industrially both synthetically and by bacterial fermentation . About 75% of acetic acid made for use in

4218-691: The genus Clostridium or Acetobacterium , can convert sugars to acetic acid directly without creating ethanol as an intermediate. The overall chemical reaction conducted by these bacteria may be represented as: These acetogenic bacteria produce acetic acid from one-carbon compounds, including methanol, carbon monoxide , or a mixture of carbon dioxide and hydrogen : This ability of Clostridium to metabolize sugars directly, or to produce acetic acid from less costly inputs, suggests that these bacteria could produce acetic acid more efficiently than ethanol-oxidizers like Acetobacter . However, Clostridium bacteria are less acid-tolerant than Acetobacter . Even

4292-464: The global production has increased from 10.7 Mt/a in 2010 to 17.88 Mt/a in 2023. The two biggest producers of virgin acetic acid are Celanese and BP Chemicals. Other major producers include Millennium Chemicals , Sterling Chemicals , Samsung , Eastman , and Svensk Etanolkemi  [ sv ] . Most acetic acid is produced by methanol carbonylation . In this process, methanol and carbon monoxide react to produce acetic acid according to

4366-607: The main classes of lipids and comprising the bulk of animal fats and vegetable oils . Lactones are cyclic carboxylic esters; naturally occurring lactones are mainly 5- and 6-membered ring lactones. Lactones contribute to the aroma of fruits, butter, cheese, vegetables like celery and other foods. Esters can be formed from oxoacids (e.g. esters of acetic acid , carbonic acid , sulfuric acid , phosphoric acid , nitric acid , xanthic acid ), but also from acids that do not contain oxygen (e.g. esters of thiocyanic acid and trithiocarbonic acid ). An example of an ester formation

4440-422: The most acid-tolerant Clostridium strains can produce vinegar in concentrations of only a few per cent, compared to Acetobacter strains that can produce vinegar in concentrations up to 20%. At present, it remains more cost-effective to produce vinegar using Acetobacter , rather than using Clostridium and concentrating it. As a result, although acetogenic bacteria have been known since 1940, their industrial use

4514-448: The other hand, more frequently named using the systematic IUPAC name, based on the name for the acid followed by the suffix -oate . For example, the ester hexyl octanoate, also known under the trivial name hexyl caprylate , has the formula CH 3 (CH 2 ) 6 CO 2 (CH 2 ) 5 CH 3 . The chemical formulas of organic esters formed from carboxylic acids and alcohols usually take the form RCO 2 R' or RCOOR', where R and R' are

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4588-468: The parent alcohol and the parent acid, where the latter may be organic or inorganic. Esters derived from the simplest carboxylic acids are commonly named according to the more traditional, so-called " trivial names " e.g. as formate, acetate, propionate, and butyrate, as opposed to the IUPAC nomenclature methanoate, ethanoate, propanoate, and butanoate. Esters derived from more complex carboxylic acids are, on

4662-432: The presence of 0.1% water in glacial acetic acid lowers its melting point by 0.2 °C. A common symbol for acetic acid is AcOH (or HOAc), where Ac is the pseudoelement symbol representing the acetyl group CH 3 −C(=O)− ; the conjugate base , acetate ( CH 3 COO ), is thus represented as AcO . Acetate is the ion resulting from loss of H from acetic acid. The name "acetate" can also refer to

4736-467: The production of fatty acid esters and alcohols. Poly(ethylene terephthalate) is produced by the transesterification of dimethyl terephthalate and ethylene glycol: A subset of transesterification is the alcoholysis of diketene . This reaction affords 2-ketoesters. Alkenes undergo carboalkoxylation in the presence of metal carbonyl catalysts. Esters of propanoic acid are produced commercially by this method: A preparation of methyl propionate

4810-440: The range 1730–1750 cm assigned to ν C=O . This peak changes depending on the functional groups attached to the carbonyl. For example, a benzene ring or double bond in conjunction with the carbonyl will bring the wavenumber down about 30 cm . Esters are widespread in nature and are widely used in industry. In nature, fats are, in general, triesters derived from glycerol and fatty acids . Esters are responsible for

4884-637: The reaction conditions may be altered to produce more of them where needed. However, the separation of acetic acid from these by-products adds to the cost of the process. Similar conditions and catalysts are used for butane oxidation, the oxygen in air to produce acetic acid can oxidize acetaldehyde . Using modern catalysts, this reaction can have an acetic acid yield greater than 95%. The major side-products are ethyl acetate , formic acid , and formaldehyde , all of which have lower boiling points than acetic acid and are readily separated by distillation . Acetaldehyde may be prepared from ethylene via

4958-406: The reaction is the reverse reaction of the Fischer esterification . Under basic conditions, hydroxide acts as a nucleophile, while an alkoxide is the leaving group. This reaction, saponification , is the basis of soap making. The alkoxide group may also be displaced by stronger nucleophiles such as ammonia or primary or secondary amines to give amides (ammonolysis reaction): This reaction

5032-420: The reaction of an ester with an alcohol. Unfortunately, because the leaving group is also an alcohol, the forward and reverse reactions will often occur at similar rates. Using a large excess of the reactant alcohol or removing the leaving group alcohol (e.g. via distillation ) will drive the forward reaction towards completion, in accordance with Le Chatelier's principle . Acid-catalyzed hydrolysis of esters

5106-485: The second-most-important manufacturing method, although it is usually not competitive with the carbonylation of methanol. The acetaldehyde can be produced by hydration of acetylene . This was the dominant technology in the early 1900s. Light naphtha components are readily oxidized by oxygen or even air to give peroxides , which decompose to produce acetic acid according to the chemical equation , illustrated with butane : Such oxidations require metal catalyst, such as

5180-466: The third century BC, when the Greek philosopher Theophrastus described how vinegar acted on metals to produce pigments useful in art, including white lead ( lead carbonate ) and verdigris , a green mixture of copper salts including copper(II) acetate . Ancient Romans boiled soured wine to produce a highly sweet syrup called sapa . Sapa that was produced in lead pots was rich in lead acetate ,

5254-412: Was discovered that could operate efficiently at lower pressure with almost no by-products. US chemical company Monsanto Company built the first plant using this catalyst in 1970, and rhodium-catalyzed methanol carbonylation became the dominant method of acetic acid production (see Monsanto process ). In the late 1990s, BP Chemicals commercialised the Cativa catalyst ( [Ir(CO) 2 I 2 ] ), which

5328-606: Was estimated to consume a third of the world's production of acetic acid. The reaction consists of ethylene and acetic acid with oxygen over a palladium catalyst , conducted in the gas phase. Vinyl acetate can be polymerised to polyvinyl acetate or other polymers , which are components in paints and adhesives . The major esters of acetic acid are commonly used as solvents for inks , paints and coatings . The esters include ethyl acetate , n - butyl acetate , isobutyl acetate , and propyl acetate . They are typically produced by catalyzed reaction from acetic acid and

5402-594: Was obtained from the pyroligneous liquor , a product of the distillation of wood. The acetic acid was isolated by treatment with milk of lime , and the resulting calcium acetate was then acidified with sulfuric acid to recover acetic acid. At that time, Germany was producing 10,000 tons of glacial acetic acid, around 30% of which was used for the manufacture of indigo dye . Because both methanol and carbon monoxide are commodity raw materials, methanol carbonylation long appeared to be attractive precursors to acetic acid. Henri Dreyfus at British Celanese developed

5476-496: Was the "fast method" or "German method", first practised in Germany in 1823. In this process, fermentation takes place in a tower packed with wood shavings or charcoal . The alcohol-containing feed is trickled into the top of the tower, and fresh air supplied from the bottom by either natural or forced convection . The improved air supply in this process cut the time to prepare vinegar from months to weeks. Nowadays, most vinegar

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