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Hexafluoroacetylacetone
Hexafluoroacetylacetone is the chemical compound with the nominal formula CF3C(O)CH2C(O)CF3 (often abbreviated as hfacH). This colourless liquid is a ligand precursor and a reagent used in MOCVD. The compound exists exclusively as the enol CF3C(OH)=CHC(O)CF3. For comparison under the same conditions, acetylacetone is 85% enol. Metal complexes of the conjugate base exhibit enhanced volatility and Lewis acidity relative to analogous complexes derived from acetylacetone. The visible spectra of bis(hexafluoroacetylacetonato)copper(II) and its dehydrate have been reported in carbon tetrachloride. Compounds of the type bis(hexafluoroacetylacetonato)copper(II):Bn , where :B are Lewis bases such as N,N-dimethylacetamide, dimethyl sulfoxide, or pyridine and n = 1 or 2, have been prepared. Since bis(hexafluoroacetylacetonato)copper(II) is soluble in carbon tetrachloride, its Lewis acid properties have been studied for 1:1 adducts using a variety of Lewis bases. This organofluorine comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, using the s ... [...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] |
Trifluoromethyl Compounds
The trifluoromethyl group is a functional group that has the formula -CF3. The naming of is group is derived from the methyl group (which has the formula -CH3), by replacing each hydrogen atom by a fluorine atom. Some common examples are trifluoromethane H–, 1,1,1-trifluoroethane –, and hexafluoroacetone –CO–. Compounds with this group are a subclass of the organofluorines. Properties The trifluoromethyl group has a significant electronegativity that is often described as being intermediate between the electronegativities of fluorine and chlorine. For this reason, trifluoromethyl-substituted compounds are often strong acids, such as trifluoromethanesulfonic acid and trifluoroacetic acid. Conversely, the trifluoromethyl group lowers the basicity of compounds like trifluoroethanol. Uses The trifluoromethyl group occurs in certain pharmaceuticals, drugs, and abiotically synthesized natural fluorocarbon based compounds. The medicinal use of the trifloromethyl group dates from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diketones
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, 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 hydration is reversible. Glyoxal condenses re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelating Agents
Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are called chelants, chelators, chelating agents, or sequestering agents. They are usually organic compounds, but this is not a necessity, as in the case of zinc and its use as a maintenance therapy to prevent the absorption of copper in people with Wilson's disease. Chelation is useful in applications such as providing nutritional supplements, in chelation therapy to remove toxic metals from the body, as contrast agents in MRI scanning, in manufacturing using homogeneous catalysts, in chemical water treatment to assist in the removal of metals, and in fertilizers. Chelate effect The chelate effect is the greater affinity of chelating ligands for a metal ion than that of similar nonchelating (monodentate) ligands for the same metal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyhedron (journal)
''Polyhedron'' is a peer-reviewed scientific journal covering the field of inorganic chemistry. It was established in 1955 as the ''Journal of Inorganic and Nuclear Chemistry'' and is published by Elsevier. Abstracting and indexing ''Polyhedron'' is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 3.052. References External links * {{Official Website, http://www.journals.elsevier.com/polyhedron/ Inorganic chemistry journals Elsevier academic journals Publications established in 1955 English-language journals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microelectronics
Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture (or microfabrication) of very small electronic designs and components. Usually, but not always, this means micrometre-scale or smaller. These devices are typically made from semiconductor materials. Many components of normal electronic design are available in a microelectronic equivalent. These include transistors, capacitors, inductors, resistors, diodes and (naturally) insulators and conductors can all be found in microelectronic devices. Unique wiring techniques such as wire bonding are also often used in microelectronics because of the unusually small size of the components, leads and pads. This technique requires specialized equipment and is expensive. Digital integrated circuits (ICs) consist of billions of transistors, resistors, diodes, and capacitors. Analog circuits commonly contain resistors and capacitors as well. Inductors are used in som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The American Chemical Society
The ''Journal of the American Chemical Society'' is a weekly peer-reviewed scientific journal that was established in 1879 by the American Chemical Society. The journal has absorbed two other publications in its history, the ''Journal of Analytical and Applied Chemistry'' (July 1893) and the ''American Chemical Journal'' (January 1914). It covers all fields of chemistry. Since 2021, the editor-in-chief is Erick M. Carreira (ETH Zurich). In 2014, the journal moved to a hybrid open access publishing model. Abstracting and indexing The journal is abstracted and indexed in Chemical Abstracts Service, Scopus, EBSCO databases, ProQuest databases, Index Medicus/MEDLINE/PubMed, and the Science Citation Index Expanded. According to the ''Journal Citation Reports'', the journal has a 2021 impact factor of 16.383. Editors-in-chief The following people are or have been editor-in-chief: * 1879–1880 – Hermann Endemann * 1880–1881 – Gideon E. Moore * 1881–1882 – Hermann Endemann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,1,1-trifluoroacetone
Trifluoroacetone (1,1,1-trifluoroacetone) is an organofluorine compound with the chemical formula CF3C(O)CH3. The compound is a colorless liquid with chloroform-like odour. Preparation, reactions, uses Trifluoroacetone is produced by decarboxylation of trifluoroacetoacetic acid: :CF3C(O)CH2CO2H → CF3C(O)CH3 + CO2 The acetoacetic acid in turn is obtained via condensation of acetate and trifluoroacetate esters. Trifluoroacetone has been examined as oxidizing agent in Oppenauer oxidation, in which case hydroxyl groups of secondary alcohols can be oxidized in the presence of hydroxy groups of primary alcohols. Trifluoracetone is also used in a synthesis of 2-trifluoromethyl-7-azaindoles starting with 2,6-dihalopyridines. The derived chiral imine is used to prepare enantiopure α-trifluoromethyl alanines and diamines by a Strecker reaction followed by either nitrile hydrolysis or reduction. See also *Hexafluoroacetone Hexafluoroacetone (HFA) is a chemical compound with the formul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifluoroacetic Acid
Trifluoroacetic acid (TFA) is an organofluorine compound with the chemical formula CF3CO2H. It is a structural analogue of acetic acid with all three of the acetyl group's hydrogen atoms replaced by fluorine atoms and is a colorless liquid with a vinegar-like odor. TFA is a stronger acid than acetic acid, having an acid ionisation constant, ''K''a, that is approximately 34,000 times higher, as the highly electronegative fluorine atoms and consequent electron-withdrawing nature of the trifluoromethyl group weakens the oxygen-hydrogen bond (allowing for greater acidity) and stabilises the anionic conjugate base. TFA is widely used in organic chemistry for various purposes. Synthesis TFA is prepared industrially by the electrofluorination of acetyl chloride or acetic anhydride, followed by hydrolysis of the resulting trifluoroacetyl fluoride: : + 4 → + 3 + : + → + Where desired, this compound may be dried by addition of trifluoroacetic anhydride. An older route to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethyl Group
In organic chemistry, an ethyl group (abbr. Et) is an alkyl substituent with the formula , derived from ethane (). ''Ethyl'' is used in the International Union of Pure and Applied Chemistry's nomenclature of organic chemistry for a saturated two-carbon moiety in a molecule, while the prefix "''eth-''" is used to indicate the presence of two carbon atoms in the molecule. Ethylation Ethylation is the formation of a compound by introduction of the ethyl group. The most widely practiced example of this reaction is the ethylation of benzene with ethylene to yield ethylbenzene, a precursor to styrene, which is a precursor to polystyrene. Approximately 24.7 million tons of ethylbenzene were produced in 1999. :: Many ethyl-containing compounds are generated by electrophilic ethylation, i.e. treatment of nucleophiles with sources of Et+. Triethyloxonium tetrafluoroborate t3OF4 is such a reagent. For good nucleophiles, less electrophilic reagents are employed, such as ethyl h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include Subscript and superscript, subscripts and superscripts. A chemical formula is not a chemical nomenclature, chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called ''empirical formulae'', which use letters and numbers ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
