| Acetaldehyde | |
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| IUPAC name | acetaldehyde |
| Systematic name | ethanal |
| Identifiers | |
| CAS number | [75-07-0] |
| EINECS number | |
| RTECS number | AB1925000 |
| SMILES | CC=O |
| Properties | |
| Molecular formula | C2H4O |
| Molar mass | 44. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The EINECS number (for European Inventory of Existing Chemical Substances) is a registry number given to each Chemical substance commercially available in the Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 05 g mol−1 |
| Appearance | Colorless liquid Pungent, fruity odor |
| Density | 0. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 788 g cm−3 |
| Melting point |
−123. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 5 °C |
| Boiling point |
20. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 2 °C |
| Solubility in water | soluble in all proportions |
| Viscosity | ~0. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Viscosity is a measure of the resistance of a Fluid which is being deformed by either Shear stress or Extensional stress. 215 at 20 °C |
| Structure | |
| Molecular shape | trigonal planar (sp²) at C1 tetrahedral (sp³) at C2 |
| Dipole moment | 2. Molecular geometry or molecular structure is the three- Dimensional arrangement of the Atoms that constitute a Molecule. In physics there are two kinds of dipoles ( Hellènic: di(s- = two- and pòla = pivot hinge An electric dipole is a 7 D |
| Hazards | |
| MSDS | External MSDS |
| EU classification | Very flammable (F+) Harmful (Xn) Carc. Cat. 3 |
| NFPA 704 |
 4
2
0
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| R-phrases | R12, R36/37, R40 |
| S-phrases | (S2), S16, S33, S36/37 |
| Flash point | −39 °C |
| Autoignition temperature |
185 °C |
| Related compounds | |
| Related aldehydes | Formaldehyde Propionaldehyde Ethylene oxide |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. The debye (symbol D) is a non- SI, CGS unit of electrical dipole moment. A material safety data sheet ( MSDS) is a form containing data regarding the properties of a particular substance This page provides supplementary chemical data on Acetaldehyde Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external An aldehyde is an organic compound containing a terminal Carbonyl group. Formaldehyde is a Chemical compound with the formula H2CO It is the simplest Aldehyde —an organic compound containing a terminal Carbonyl Propionaldehyde or propanal is the Organic compound with the formula CH3CH2CHO This page provides supplementary chemical data on Acetaldehyde This page provides supplementary chemical data on Acetaldehyde The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium Measurement The relative static permittivity εr can be measured for static Electric fields as follows first the Capacitance of a test |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Acetaldehyde, sometimes known as ethanal, is an organic chemical compound with the formula CH3CHO or MeCHO. This page provides supplementary chemical data on Acetaldehyde This page provides supplementary chemical data on Acetaldehyde Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry ( UV/ VIS) involves the Spectroscopy of Photons in the UV-visible Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum. Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is the name given to a technique which exploits the magnetic properties of certain nuclei Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon. A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the It is a flammable liquid with a fruity smell. Acetaldehyde occurs naturally in ripe fruit, coffee, and fresh bread, and is produced by plants as part of their normal metabolism. The term fruit has different meanings dependent on context and the term is not synonymous in Food preparation and Biology. CoFFEE is an Open source Software for computer supported collaborative learning (CSCL in a digital classroom Bread is a Staple food prepared by Baking a Dough of Flour and Water. Plants are living Organisms belonging to the kingdom Plantae. Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life. It is popularly known as the chemical that causes hangovers. A hangover ( veisalgia) describes the sum of unpleasant physiological effects following heavy consumption of drugs particularly Alcoholic beverages The most commonly [1]
In the chemical industry, acetaldehyde is used as an intermediate in the production of acetic acid, certain esters, and a number of other chemicals. Acetic acid, also known as ethanoic acid, is an organic chemical compound, giving Vinegar its sour taste Esters are a class of Chemical compounds and Functional groups Esters consist of an inorganic or organic Acid in which at least In 1989, US production stood at 740 million pounds (336,000 Mg). An important production method for acetaldehyde is the Wacker process. The Wacker process or the Hoechst-Wacker process (named after the chemical companies of the same name originally referred to the oxidation of Ethylene to Acetaldehyde
Contents |
Biological aspects
In the liver, the enzyme alcohol dehydrogenase converts ethanol into acetaldehyde, which is then further converted into harmless acetic acid by acetaldehyde dehydrogenase. The liver is a vital organ in the human body and is present in Vertebrates and some other animals Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Alcohol dehydrogenase (ADH is an enzyme discovered in the mid-1960s in Drosophila melanogaster. Acetic acid, also known as ethanoic acid, is an organic chemical compound, giving Vinegar its sour taste Acetaldehyde dehydrogenase s ( are Dehydrogenase Enzymes which catalyze the conversion of Acetaldehyde into Acetic acid. The last steps of alcoholic fermentation in bacteria, plants and yeast involve the conversion of pyruvate into acetaldehyde by the enzyme pyruvate decarboxylase, followed by the conversion of acetaldehyde into ethanol. Fermentation in Food processing typically refers to the conversion of Sugar to Alcohol using Yeast under Anaerobic conditions The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Plants are living Organisms belonging to the kingdom Plantae. Yeasts are a growth form of eukaryotic Microorganisms classified in the kingdom Fungi, with about 1500 Species currently described Pyruvic acid (CH3COCO2H is an alpha-keto acid. The Carboxylate Anion of pyruvic acid is known as pyruvate. Pyruvate decarboxylase is a Homotetrameric Enzyme ( that catalyses the decarboxylation of Pyruvic acid to Acetaldehyde The latter reaction is again catalyzed by an alcohol dehydrogenase, now operating in the opposite direction.
Acetaldehyde and hangovers
Most people of East Asian descent have a mutation in their alcohol dehydrogenase gene that makes this enzyme unusually effective at converting ethanol to acetaldehyde, and about half of such people also have a form of acetaldehyde dehydrogenase that is less effective at converting acetaldehyde to acetic acid. In biology mutations are changes to the Nucleotide sequence of the Genetic material of an organism Alcohol dehydrogenase (ADH is an enzyme discovered in the mid-1960s in Drosophila melanogaster. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance Acetaldehyde dehydrogenase s ( are Dehydrogenase Enzymes which catalyze the conversion of Acetaldehyde into Acetic acid. [2] This combination causes them to suffer from the alcohol flush reaction, in which acetaldehyde accumulates after drinking, leading to severe and immediate hangover symptoms. Alcohol flush reaction is a condition in which the body cannot break down ingested alcohol completely due to a missense polymorphism that encodes the enzyme Acetaldehyde These people are therefore less likely to become alcoholics. Alcoholism is a term with multiple and sometimes conflicting definitions The drug disulfiram (Antabuse) also prevents the oxidation of acetaldehyde to acetic acid, with the same unpleasant effects for drinkers. Disulfiram is a drug used It is used in the treatment of alcoholism.
Applications in organic synthesis
Acetaldehyde is a common 2-carbon building block in organic synthesis. Organic synthesis is a special branch of Chemical synthesis and is concerned with the construction of Organic compounds via Organic reactions Organic [3] Because of its small size and its availability as the anhydrous monomer (unlike formaldehyde), it is a common electrophile. With respect to its condensation reactions, acetaldehyde is prochiral. In Chemistry, prochiral molecules can be converted from achiral to chiral in a single step It is mainly used as a source of the CH3C+H(OH) synthon in aldol and related condensation reactions. A synthon is a concept in Retrosynthetic analysis. It is defined as a structural unit within a Molecule which is related to a possible synthetic operation An Aldol condensation is an Organic reaction in which an Enolate ion reacts with a Carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone followed [4] Grignard reagents and organolithium compounds react with MeCHO to give hydroxyethyl derivatives. [5] In one of the more spectacular condensation reactions, three equivalents of formaldehyde add to MeCHO to give pentaerythritol, C(CH2OH)4. Formaldehyde is a Chemical compound with the formula H2CO It is the simplest Aldehyde —an organic compound containing a terminal Carbonyl Pentaerythritol is the Organic compound with the formula C(CH2OH4 [6]
In a Strecker reaction, acetaldehyde condenses with cyanide and ammonia to give, after hydrolysis, the amino acid alanine. The Strecker amino acid synthesis, devised by Adolph Strecker, is a series of Chemical reactions that synthesize an Amino acid from an Aldehyde A cyanide is any Chemical compound that contains the cyano group (C≡N which consists of a Carbon Atom triple-bonded to a Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this [7] Acetaldehyde can condense with amines to yield imines, such as the condensation with cyclohexylamine to give N-ethylidenecyclohexylamine. These imines can be used to direct subsequent reactions like an aldol condensation. [8]
It is also an important building block for the synthesis of heterocyclic compounds. A remarkable example is its conversion upon treatment with ammonia to 5-ethyl-2-methylpyridine ("aldehyde-collidine”). Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor [9]
Acetal derivatives
Three molecules of acetaldehyde condense to form “paraldehyde,” a cyclic trimer containing C-O single bonds; four condense to form the cyclic molecule called metaldehyde. Paraldehyde is the cyclic form of three Acetaldehyde molecules (a trimer Metaldehyde is a chemical that is commonly used as a Pesticide against Slugs Snails and other Gastropods Metaldehyde is a cyclic Oligomer
Acetaldehyde forms a stable acetal upon reaction with ethanol under conditions that favor dehydration. An acetal is a Molecule with two single bonded oxygens attached to the same carbon atom The product, CH3CH(OCH2CH3)2, is in fact called "acetal,"[10] although acetal is used more widely to describe other compounds with the formula RCH(OR')2. An acetal is a Molecule with two single bonded oxygens attached to the same carbon atom
Ethenol
Only a trace of acetaldehyde exists as the enol form, ethenol, with Keq = 6 x 10-5. Enols (also known as alkenols) are Alkenes with a Hydroxyl group affixed to one of the carbon atoms composing the Double bond. Ethenol, also called vinyl alcohol, hydroxyethene or hydroxyethylene, is an Alcohol with Chemical formula 23 [11]
Environmental occurrence
Acetaldehyde is an air pollutant resulting from combustion, such as automotive exhaust and tobacco smoke. Air pollution is the human introduction into the atmosphere of Chemicals Particulate matter, or Biological materials that cause harm or discomfort Tobacco Smoking is the inhalation of smoke from burned dried or cured leaves of the Tobacco plant most often in the form of a Cigarette. It is also created by thermal degradation of polymers in the plastics processing industry. For the biological process see Decomposition. For chemical decomposition in general see Chemical decomposition. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products [12]
Safety
Acetaldehyde is toxic when applied externally for prolonged periods, an irritant, and a probable carcinogen. The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation [13]
References
- ^ How Hangovers Work, HowStuffWorks
- ^ Xiao Q, Weiner H, Crabb DW (1996). "The mutation in the mitochondrial aldehyde dehydrogenase (ALDH2) gene responsible for alcohol-induced flushing increases turnover of the enzyme tetramers in a dominant fashion". J. Clin. Invest. 98 (9): 2027-32. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 8903321.
- ^ Sowin, T. J. ; Melcher, L. M. ”Acetaldehyde” in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289
- ^ Behrens, C. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. ; Paquette, L. A. (2004). "N-Benzyl-2,3-Azetidinedione". Org. Synth.; Coll. Organic Syntheses is a Scientific journal that since 1921 has provided the Chemistry community with annual collections of detailed and checked procedures Vol. 10: 41.
- ^ Walter, L. A. (1955). "1-(α-Pyridyl)-2-Propanol". Org. Synth.; Coll. Organic Syntheses is a Scientific journal that since 1921 has provided the Chemistry community with annual collections of detailed and checked procedures Vol. 3: 757.
- ^ Schurink, H. B. J. (1941). "Pentaerythritol". Org. Synth.; Coll. Organic Syntheses is a Scientific journal that since 1921 has provided the Chemistry community with annual collections of detailed and checked procedures Vol. 1: 425.
- ^ Kendall, E. C. McKenzie, B. F. (1941). "dl-Alanine". Org. Synth.; Coll. Organic Syntheses is a Scientific journal that since 1921 has provided the Chemistry community with annual collections of detailed and checked procedures Vol. 1: 21.
- ^ Wittig, G.; Hesse, A. Georg Wittig ( June 16, 1897 &ndash August 26 1987) was a German Chemist who reported a method for synthesis of (1988). "Directed Aldol Condensations: β-Phenylcinnamaldehyde". Org. Synth.; Coll. Organic Syntheses is a Scientific journal that since 1921 has provided the Chemistry community with annual collections of detailed and checked procedures Vol. 6: 901.
- ^ Frank, R. L. ; Pilgrim, F. J. ; Riener, E. F. (1963). "5-Ethyl-2-Methylpyridine". Org. Synth.; Coll. Organic Syntheses is a Scientific journal that since 1921 has provided the Chemistry community with annual collections of detailed and checked procedures Vol. 4: 451.
- ^ Adkins, H. ; Nissen, B. H. (1941). "Acetal". Org. Synth.; Coll. Organic Syntheses is a Scientific journal that since 1921 has provided the Chemistry community with annual collections of detailed and checked procedures Vol. 1: 1.
- ^ March, J. “Organic Chemistry: Reactions, Mechanisms, and Structures” J. Wiley, New York: 1992. ISBN 0-471-58148-8.
- ^ Smoking. (2006). Encyclopædia Britannica. The Encyclopædia Britannica is a general English-language encyclopaedia published by Encyclopædia Britannica Inc Accessed 27 Oct 2006.
- ^ Chemical Summary For Acetaldehyde, US Environmental Protection Agency
See also
External links
- International Chemical Safety Card 0009
- National Pollutant Inventory - Acetaldehde
- NIOSH Pocket Guide to Chemical Hazards
- IARC Monograph: "Acetaldehyde"
- Hal Kibbey, Genetic Influences on Alcohol Drinking and Alcoholism, Indiana University Research and Creative Activity, Vol. A wine fault or defect is an unpleasant characteristic of a Wine often resulting from poor Winemaking practices 17 no. 3.
- United States Food and Drug Administration (FDA) information for acetaldehyde
Dictionary
acetaldehyde
-noun
- (organic chemistry) An organic compound (CH3CHO). Sometimes called ethanal or acetic aldehyde. See aldehyde.
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