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Orthocarbonate
Orthocarbonic acid (methanetetrol) is the name given to a hypothetical compound with the chemical formula or . Its molecular structure consists of a single carbon atom bonded to four hydroxy groups. It would be therefore a fourfold alcohol. In theory it could lose four protons to give the hypothetical oxocarbon anion (orthocarbonate), and is therefore considered an oxoacid of carbon. The compound has also been given the nickname of "Hitler's Acid" due to the Ball-and-stick model of the compound resembling the Swastika symbol. Orthocarbonic acid is highly unstable. Calculations show that it decomposes spontaneously into carbonic acid and water: : H4CO4 -> H2CO3 + H2O Orthocarbonic acid is one of the group of ''ortho acids'' that have the general structure of .The term ''ortho acid'' is also used to refer to the most hydroxylated acid in a set of oxoacids. Researchers predict that orthocarbonic acid is stable at high pressure; hence it may form in the interior of the ice gia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetramethoxymethane
Tetramethoxymethane is a chemical compound which is formally formed by complete methylation of the hypothetical orthocarbonic acid C(OH)4 (orthocarboxylic acid violates the Erlenmeyer Rule, Erlenmeyer rule and is unstable in free state). Preparation The obvious synthetic route from tetrachloromethane does not yield the desired product.R. H. De Wolfe, ''Carboxylic ortho acid derivatives: preparation and synthetic applications'', Organic Chemistry, Vol. 14, Academic Press, Inc. New York – London, 1970, . The original preparation of the tetramethoxymethane was therefore based on chloropicrin: Because of the unpleasant properties of the chloropicrin, other tetrasubstituted reactive methane derivatives were investigated as starting material for tetramethoxymethane. For example, trichloromethanesulfenyl chloride (also used as a chemical warfare agent and easily accessible from Carbon disulfide, carbon bisulfide and chlorine) was used: A less problematic synthesis is based on tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethoxymethane
Tetraethoxymethane is a chemical compound which is formally formed by complete ethylation of the hypothetical orthocarbonic acid C(OH)4 (orthocarboxylic acid violates the Erlenmeyer Rule, Erlenmeyer rule and is unstable in free state). History Tetraethoxymethane was described the first time in 1864.H. Bassett, ''Ueber das vierfach-basische kohlensaure Aethyl'', Ann. 132, 54 (1864), . Synthesis The preparation of tetraethoxymethane from the highly toxic trichloronitromethane is known in the literatureEuropäische Patentschrift EP 0881212 B1''Production method of aminobenzene compound'' Erfinder: H. Hashimoto et al., Anmelder: Takeda Chemical Industries, Ltd., veröffentlicht am 30. Oktober 2001. and achieves only yields of 46-49 to 58%: The obvious synthetic route from tetrachloromethane does not provide the desired product, as in the homologous tetramethoxymethane.R.H. De Wolfe, ''Carboxylic ortho acid derivatives: preparation and synthetic applications'', Organic Chemistry, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethoxymethane
Tetraethoxymethane is a chemical compound which is formally formed by complete ethylation of the hypothetical orthocarbonic acid C(OH)4 (orthocarboxylic acid violates the Erlenmeyer Rule, Erlenmeyer rule and is unstable in free state). History Tetraethoxymethane was described the first time in 1864.H. Bassett, ''Ueber das vierfach-basische kohlensaure Aethyl'', Ann. 132, 54 (1864), . Synthesis The preparation of tetraethoxymethane from the highly toxic trichloronitromethane is known in the literatureEuropäische Patentschrift EP 0881212 B1''Production method of aminobenzene compound'' Erfinder: H. Hashimoto et al., Anmelder: Takeda Chemical Industries, Ltd., veröffentlicht am 30. Oktober 2001. and achieves only yields of 46-49 to 58%: The obvious synthetic route from tetrachloromethane does not provide the desired product, as in the homologous tetramethoxymethane.R.H. De Wolfe, ''Carboxylic ortho acid derivatives: preparation and synthetic applications'', Organic Chemistry, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters 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 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. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moiety (chemistry)
In organic chemistry, a moiety ( ) is a part of a molecule that is given a name because it is identified as a part of other molecules as well. Typically, the term is used to describe the larger and characteristic parts of organic molecules, and it should not be used to describe or name smaller functional groups of atoms that chemically react in similar ways in most molecules that contain them. Occasionally, a moiety may contain smaller moieties and functional groups. A moiety that acts as a branch extending from the backbone of a hydrocarbon molecule is called a substituent or side chain, which typically can be removed from the molecule and substituted with others. Active moiety In pharmacology, an active moiety is the part of a molecule or ion – excluding appended inactive portions – that is responsible for the physiological or pharmacological action of a drug substance. Inactive appended portions of the drug substance may include either the alcohol or acid moiety of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valence (chemistry)
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules. Description The combining capacity, or affinity of an atom of a given element is determined by the number of hydrogen atoms that it combines with. In methane, carbon has a valence of 4; in ammonia, nitrogen has a valence of 3; in water, oxygen has a valence of 2; and in hydrogen chloride, chlorine has a valence of 1. Chlorine, as it has a valence of one, can be substituted for hydrogen. Phosphorus has a valence of 5 in phosphorus pentachloride, . Valence diagrams of a compound represent the connectivity of the elements, with lines drawn between two elements, sometimes called bonds, representing a saturated valency for each element. The two tables below show some examples of different compounds, their valence diagrams, and the valences for each element of the compound. Modern definitions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Pressure
Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 760mm Hg, 29.9212 inchesHg, or 14.696psi.International Civil Aviation Organization. ''Manual of the ICAO Standard Atmosphere'', Doc 7488-CD, Third Edition, 1993. . The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth; that is, the Earth's atmospheric pressure at sea level is approximately 1 atm. In most circumstances, atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. As elevation increases, there is less overlying atmospheric mass, so atmospheric pressure decreases with increasing elevation. Because the atmosphere is thin relative to the Earth's radius—especially the dense atmospheric layer at low altitudes—the Earth's gravi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angstrom
The angstromEntry "angstrom" in the Oxford online dictionary. Retrieved on 2019-03-02 from https://en.oxforddictionaries.com/definition/angstrom.Entry "angstrom" in the Merriam-Webster online dictionary. Retrieved on 2019-03-02 from https://www.merriam-webster.com/dictionary/angstrom. (, ; , ) or ångström is a metric unit of length equal to m; that is, one ten-billionth ( US) of a metre, a hundred-millionth of a centimetre,Entry "angstrom" in the Oxford English Dictionary, 2nd edition (1986). Retrieved on 2021-11-22 from https://www.oed.com/oed2/00008552. 0.1 nanometre, or 100 picometres. Its symbol is Å, a letter of the Swedish alphabet. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–1874). The angstrom is often used in the natural sciences and technology to express sizes of atoms, molecules, microscopic biological structures, and lengths of chemical bonds, arrangement of atoms in crystals,Arturas Vailionis (2015):Geometry of Crystals Lect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahedral Molecular Geometry
In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos−1(−) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane () as well as its heavier analogues. Methane and other perfectly symmetrical tetrahedral molecules belong to point group Td, but most tetrahedral molecules have lower symmetry. Tetrahedral molecules can be chiral. Tetrahedral bond angle The bond angle for a symmetric tetrahedral molecule such as CH4 may be calculated using the dot product of two vectors. As shown in the diagram, the molecule can be inscribed in a cube with the tetravalent atom (e.g. carbon) at the cube centre which is the origin of coordinates, O. The four monovalent atoms (e.g. hydrogens) are at four corners of the cube (A, B, C, D) chosen so that no two atoms are at adjacent corners linked by only one cube edge. If the edge length of the cube ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt (chemistry)
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions. The component ions in a salt compound can be either inorganic, such as chloride (Cl−), or organic, such as acetate (). Each ion can be either monatomic, such as fluoride (F−), or polyatomic, such as sulfate (). Types of salt Salts can be classified in a variety of ways. Salts that produce hydroxide ions when dissolved in water are called ''alkali salts'' and salts that produce hydrogen ions when dissolved in water are called ''acid salts''. ''Neutral salts'' are those salts that are neither acidic nor basic. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered salts. Examples of zwitterions are amino acids, many metabolites, peptid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
