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Imides
In organic chemistry, an imide is a functional group consisting of two acyl groups bound to nitrogen. The compounds are structurally related to acid anhydrides, although imides are more resistant to hydrolysis. In terms of commercial applications, imides are best known as components of high-strength polymers, called polyimides. Inorganic imides are also known as solid state or gaseous compounds, and the imido group (=NH) can also act as a ligand. Examples Simple example is diacetamide with the formula , formally the diacetylated derivative of ammonia. Commonly encountered imides, however, are cyclic, being derived from dicarboxylic acids. A common example is succinimide derived from succinic acid and ammonia. The names of these cyclic imides reflect the parent acid. Many imides are derived from primary amines as opposed to ammonia. These are indicated by ''N''-substituent in the prefix. For example, N-ethylsuccinimide is derived from succinic acid and ethylamine. : Prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Imide
The inorganic imide is an inorganic chemical compound containing *an anion with the chemical formula , in which nitrogen atom is covalently bonded to one hydrogen atom (as in lithium imide and calcium imide ). The other name of that anion is monohydrogen nitride. *functional groups with the chemical formulas or , in which nitrogen atom is also covalently bonded to one hydrogen atom, with two covalent single bonds or one covalent double bond from the nitrogen atom to other atoms, respectively (as in heptasulfur imide , sulfur diimide and nitroxyl ). Imide, Organic imides have the functional groups or as well. The imides are related to the inorganic amides, containing the anions, the nitrides, containing the anions and the nitridohydrides or nitride hydrides, containing both nitride and hydride anions. In addition to solid state imides, molecular imides are also known in dilute gases, where their spectrum can be studied. When covalently bound to a metal, an imide ligand p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diacetamide
Diacetamide is an organic compound with the formula . It can be classified as an imide. It is a white solid. Diacetamide can be prepared by acetylation of acetamide Acetamide (systematic name: ethanamide) is an organic compound with the formula CH3CONH2. It is an amide derived from ammonia and acetic acid. It finds some use as a plasticizer and as an industrial solvent. The related compound ''N'',''N''-dime .... The compound serves as a bidentate O,O chelating ligand for a variety of metal ions.{{cite journal , doi=10.1016/0022-2860(76)85081-8 , title=Spectra and structure of iron(III) complexes with carbamide derivatives containing an acetyl group , date=1976 , last1=Massowska , first1=Joanna , last2=Cedzyńska , first2=Krystyna , journal=Journal of Molecular Structure , volume=33 , issue=2 , pages=183–189 , bibcode=1976JMoSt..33..183M References Acetamides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maleic Acid
Maleic acid or ''cis''-butenedioic acid is an organic compound that is a dicarboxylic acid, a molecule with two carboxyl groups. Its chemical formula is HO2CCH=CHCO2H. Maleic acid is the ''cis'' Cis–trans isomerism, isomer of butenedioic acid, whereas fumaric acid is the ''trans'' isomer. Maleic acid is mainly used as a precursor to fumaric acid, and relative to its parent maleic anhydride, which has many applications. Etymology 'Maleic acid' from the French altered from , malic acid, from which it was synthesised. The word 'malic' is derived from Latin , meaning 'apple'. Physical properties Maleic acid has a heat of combustion of −1,355 kJ/mol., 22.7 kJ/mol higher than that of fumaric acid. Maleic acid is more soluble in water than fumaric acid. The melting point of maleic acid (135 °C) is also much lower than that of fumaric acid (287 °C). As confirmed by X-ray crystallography, maleic acid is planar. Two normal hydrogen bonds are observed, one Intramolec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalidomide
Thalidomide, sold under the brand names Contergan and Thalomid among others, is an oral administered medication used to treat a number of cancers (e.g., multiple myeloma), graft-versus-host disease, and many skin disorders (e.g., complications of leprosy such as skin lesions). Updated as required. Thalidomide has been used to treat conditions associated with HIV: aphthous ulcers, HIV-associated wasting syndrome, diarrhea, and Kaposi's sarcoma, but increases in HIV viral load have been reported. Common side effects include sleepiness, rash, and dizziness. Severe side effects include tumor lysis syndrome, blood clots, and peripheral neuropathy. Thalidomide is a known human teratogen and carries an extremely high risk of severe, life-threatening birth defects if administered or taken during pregnancy. It causes skeletal deformities such as Amelia (birth defect), amelia (absence of legs and/or arms), absence of bones, and phocomelia (malformation of the limbs). A single dose of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloheximide
Cycloheximide is a naturally occurring fungicide produced by the bacterium '' Streptomyces griseus''. Cycloheximide exerts its effects by interfering with the translocation step in protein synthesis (movement of two tRNA molecules and mRNA in relation to the ribosome), thus blocking eukaryotic translational elongation. Cycloheximide is widely used in biomedical research to inhibit protein synthesis in eukaryotic cells studied ''in vitro'' (''i.e.'' outside of organisms). It is inexpensive and works rapidly. Its effects are rapidly reversed by simply removing it from the culture medium. Due to significant toxic side effects, including DNA damage, teratogenesis, and other reproductive effects (including birth defects and toxicity to sperm), cycloheximide is generally used only in ''in vitro'' research applications, and is not suitable for human use as a therapeutic compound. Although it has been used as a fungicide in agricultural applications, this application is now decreas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kapton
file:Kaptonpads.jpg, Kapton insulating pads for mounting electronic parts on a heat sink Kapton is a polyimide film used in flexible printed circuits (flexible electronics) and space blankets, which are used on spacecraft, satellites, and various space instruments. Invented by the DuPont (1802-2017), DuPont Corporation in the 1960s, Kapton remains stable across a wide range of temperatures, from . Kapton is used in electronics manufacturing and space applications, with x-ray equipment, and in 3D printing applications. Its favorable thermal properties and outgassing characteristics result in its regular use in Cryogenics, cryogenic applications and in high vacuum environments. History Kapton was invented by DuPont in the 1960s. Kapton remains manufactured by DuPont to this day. The name ''Kapton'' is a registered trademark of E. I. du Pont de Nemours and Company. Chemistry and variants Kapton synthesis is an example of the use of a wikt:dianhydride, dianhydride in step pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyimide
Polyimide (sometimes abbreviated PI) is a monomer containing imide groups belonging to the class of high-performance plastics. With their high heat-resistance, polyimides enjoy diverse applications in roles demanding rugged organic materials, such as high temperature fuel cells, displays, and various military roles. A classic polyimide is Kapton, which is produced by condensation of pyromellitic dianhydride and 4,4'-oxydianiline.Wright, Walter W. and Hallden-Abberton, Michael (2002) "Polyimides" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim. History The first polyimide was discovered in 1908 by Bogart and Renshaw. They found that 4-amino phthalic anhydride does not melt when heated but does release water upon the formation of a high molecular weight polyimide. The first semialiphatic polyimide was prepared by Edward and Robinson by melt fusion of diamines and tetra acids or diamines and diacids/diester. However, the first polyimide of significant co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Bond
In chemistry, a hydrogen bond (H-bond) is a specific type of molecular interaction that exhibits partial covalent character and cannot be described as a purely electrostatic force. It occurs when a hydrogen (H) atom, Covalent bond, covalently bonded to a more Electronegativity, electronegative donor atom or group (Dn), interacts with another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor (Ac). Unlike simple Dipole–dipole attraction, dipole–dipole interactions, hydrogen bonding arises from charge transfer (nB → σ*AH), Atomic orbital, orbital interactions, and quantum mechanical Delocalized electron, delocalization, making it a resonance-assisted interaction rather than a mere electrostatic attraction. The general notation for hydrogen bonding is Dn−H···Ac, where the solid line represents a polar covalent bond, and the dotted or dashed line indicates the hydrogen bond. The most frequent donor and acceptor atoms are nitrogen (N), oxyg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recrystallization (chemistry)
Recrystallization is a broad class of List of purification methods in chemistry , chemical purification techniques characterized by the dissolution of an impure sample in a solvent or solvent mixture, followed by some change in conditions that encourages the formation of pure isolate as solid crystals. Recrystallization as a purification technique is driven by spontaneous process , spontaneous processes of molecular self-assembly , self-assembly that leverage the highly ordered (i.e. low-entropy) and periodic characteristics of a crystal's molecular structure to produce purification. Basic principles The driving force of this purification emerges from the difference in molecular interactions between the isolate and the impurities: if a molecule of the desired isolate interacts with any isolate crystal present, it is likely the molecule Deposition (chemistry) , deposits on the crystal's ordered surface and contributes to the crystal's growth; if a molecule of the impurity inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phthalic Acid
In organic chemistry, phthalic acid is an aromatic dicarboxylic acid, with formula and structure . Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large scale. Phthalic acid is one of three isomers of benzenedicarboxylic acid, the others being isophthalic acid and terephthalic acid. Production Phthalic acid is produced by the catalytic oxidation of naphthalene or ''ortho-''xylene directly to phthalic anhydride and a subsequent hydrolysis of the anhydride. Phthalic acid was first obtained by French chemist Auguste Laurent in 1836 by oxidizing naphthalene tetrachloride. Believing the resulting substance to be a naphthalene derivative, he named it "naphthalic acid". After the Swiss chemist Jean Charles Galissard de Marignac determined its correct formula, Laurent gave it its present name. Manufacturing methods in the nineteenth century included oxidation of naphthalene tetrach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
