quaternary ammonium compounds

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• Quaternary ammonium muscle relaxants — are quaternary ammonium salts used as drugs for muscle relaxation, most commonly in anasthesia. It is necessary to prevent spontaneous movement of muscle during surgical operations. Muscle relaxants inhibit neuron transmission to muscle by… …   Wikipedia

• Quaternary ammonium cation — Quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure NR4+ with R being alkyl groups. Unlike the ammonium ion NH4+ itself and primary, secondary, or tertiary ammonium cations, the quaternary… …   Wikipedia

• quaternary ammonium compound — noun a compound derived from ammonium with hydrogen atoms replaced by organic groups; used as surface active agents, disinfectants, and in drugs • Hypernyms: ↑organic compound * * * noun also quaternary ( es) : any of a large class of strong… …   Useful english dictionary

• quaternary ammonium compound — n. any of a class of compounds in which the four hydrogen atoms of the ammonium radical are replaced by other groups, generally organic radicals: used as solvents, disinfectants, etc …   English World dictionary

• quaternary ammonium compound — Chem. any of a class of salts derived from ammonium in which the nitrogen atom is attached to four organic groups, as in benzalkonium chloride; the salts are cationic surface active compounds used as antiseptics and disinfectants. Also called… …   Universalium

• Trimethyl ammonium compounds — are a type of quaternary ammonium compound with three methyl groups at the nitrogen, with a more complicated carbon chain derivative at the fourth position.Examples include: * Betaine * Bethanechol * Carnitine and its derivatives * Choline and… …   Wikipedia

• quaternary ammonium compound — noun any of a class of compounds with the general formula, R4N+, formally derived from ammonium hydroxide …  

• ammonium — The ion, NH4+, formed by combination of NH3 and H+ (the pKa value is 9.24); behaves as a univalent metal in forming a. compounds. a. benzoate has been used as a stimulant, diuretic, urinary antiseptic, and …   Medical dictionary

• Ammonium — This article is about the cation. For the ancient city, see Siwa Oasis. The NH4+ ion …   Wikipedia

• quaternary — 1. Denoting a chemical compound containing four elements; e.g., NaHSO4. Cf.:q. structure. 2. Fourth in a series. 3. Relating to organic compounds in which some central atom is attached to four functional groups; applied to the usually trivalent… …   Medical dictionary

• Onium compounds — are cations derived by the protonation of mononuclear parent hydrides of elements of the nitrogen group (Group 15), chalcogens (Group 16), or halogens (Group 17), and similar cations derived by the substitution of hydrogen atoms in the former by… …   Wikipedia