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Pinacyanol
Pinacyanol is a cyanine dye. It is an organic cation, typically isolated as the chloride or iodide salts. The blue dye is prepared from 2-methylquinoline by quaternization with ethyl chloride or ethyl iodide. Condensation with formaldehyde results in coupling. Subsequent oxidation of the leuco intermediate gives the dye. Pinacyanol is a prototypical cyanine dye that was widely used as a sensitizer in electrophotography Xerography is a dry photocopying technique. Originally called electrophotography, it was renamed xerography—from the roots el, ξηρός, label=none ''xeros'', meaning "dry" and -γραφία ''-graphia'', meaning "writing"—to emphasize .... Its biological properties have also been investigated widely.{{cite journal , doi=10.1021/cb600362d, title=Inhibition of Angiogenesis by the Antifungal Drug Itraconazole, year=2007, last1=Chong, first1=Curtis R., last2=Xu, first2=Jing, last3=Lu, first3=Jun, last4=Bhat, first4=Shridhar, last5=Sullivan, first5=Davi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanine Dye
Cyanines, also referred to as tetramethylindo(di)-carbocyanines are a synthetic dye family belonging to the polymethine group. Although the name derives etymologically from terms for shades of blue, the cyanine family covers the electromagnetic spectrum from near IR to UV. Chemically, cyanines are a conjugated system between two nitrogen atoms; in each resonance structure, exactly one nitrogen atom is oxidized to an iminium. Typically, they form part of a nitrogenous heterocyclic system. The main application for cyanine dyes is in biological labeling. Nevertheless, there is a wide literature on both their synthesis and uses, and cyanines are common in some CD and DVD media. Structure Cyanines have been classified in many ways: * ''Streptocyanines'' or ''open chain cyanines'': : R2N+=CH H=CH'n''-NR2 (I) * ''Hemicyanines'': : Aryl=N+=CH H=CH'n''-NR2 (II) * ''Closed chain cyanines'': :Aryl=N+=CH H=CH'n''-N=Aryl (III) Additionally, these classes are recognized: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cation
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Methylquinoline
Quinaldine or 2-methylquinoline is an organic compound with the formula CH3C9H6N. It is one of the methyl derivatives of the heterocyclic compound quinoline. It is bioactive and is used in the preparation of various dyes. It is a colorless oil but commercial samples can appear colored. Production and reactions Quinaldine is recovered from coal tar. It can be prepared from aniline and paraldehyde via Skraup synthesis or from aniline and crotonaldehyde via Doebner-von Miller variation of the Skraup reaction. Hydrogenation of quinaldine gives 2-methyltetrahydroquinoline. This reduction can be conducted enantioselectively. Properties Quinaldine has critical point at 787 K and 4.9 MPa and its refractive index is 1.8116. Uses Quinaldine is used in manufacturing anti-malaria drugs, dyes and food colorants (e.g., Quinoline Yellows, pinacyanol Pinacyanol is a cyanine dye. It is an organic cation, typically isolated as the chloride or iodide salts. The blue dye is prepared fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternization
In organic chemistry, the Menshutkin reaction converts a tertiary amine into a quaternary ammonium salt by reaction with an alkyl halide. Similar reactions occur when tertiary phosphines are treated with alkyl halides. The reaction is the method of choice for the preparation quaternary ammonium salts. Some phase transfer catalysts (PTC) can be prepared according to the Menshutkin reaction, for instance the synthesis of triethyl benzyl ammonium chloride (TEBA) from triethylamine and benzyl chloride: Scope Reactions are typically conducted in polar solvents such as alcohols. Alkyl iodides are superior alkylating agents relative to the bromides, which in turn are superior to chlorides. As is typical for an SN2 process, benzylic, allylic, and α-carbonylated alkyl halides are excellent reactants. Even though alkyl chlorides are poor alkylating agents (''gem''-dichlorides especially so), amines should not be handled in chlorinated solvents such as dichloromethane and dichlo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethyl Chloride
Chloroethane, commonly known as ethyl chloride, is a chemical compound with chemical formula CH3CH2Cl, once widely used in producing tetraethyllead, a gasoline additive. It is a colorless, flammable gas or refrigerated liquid with a faintly sweet odor. Production Chloroethane is produced by hydrochlorination of ethylene: :C2H4 + HCl → C2H5Cl At various times in the past, chloroethane has also been produced from ethanol and hydrochloric acid, from ethane and chlorine, or from ethanol and phosphorus trichloride, but these routes are no longer economical. Some chloroethane is generated as a byproduct of polyvinyl chloride production. Uses Chloroethane is an inexpensive ethylating agent. It reacts with aluminium metal to give ethylaluminium sesquichloride, a precursor to polymers and other useful organoaluminium compounds. Chloroethane is used to convert cellulose to ethylcellulose, a thickening agent and binder in paints, cosmetics, and similar products. Like other chlorinated h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophotography
Xerography is a dry photocopying technique. Originally called electrophotography, it was renamed xerography—from the roots el, ξηρός, label=none ''xeros'', meaning "dry" and -γραφία ''-graphia'', meaning "writing"—to emphasize that unlike reproduction techniques then in use such as cyanotype, the process of xerography used no liquid chemicals. History Xerography was invented by American physicist Chester Carlson, based significantly on contributions by Hungarian physicist Pál Selényi. Carlson applied for and was awarded on October 6, 1942. Carlson's innovation combined electrostatic printing with photography, unlike the dry electrostatic printing process invented by Georg Christoph Lichtenberg in 1778. Carlson's original process was cumbersome, requiring several manual processing steps with flat plates. In 1946, Carlson signed an agreement with Haloid Photographic Company to develop it as a commercial product. Before that year, Carlson had proposed his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
