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amino group

amino group, in chemistry, functional group that consists of a nitrogen atom attached by single bonds to hydrogen atoms, alkyl groups, aryl groups, or a combination of these three. An organic compound that contains an amino group is called an amine. Amines are derivatives of the inorganic compound ammonia, NH3. When one, two, or all three of the hydrogens in ammonia are replaced by an alkyl or aryl group, the resulting compound is known as a primary, secondary, or tertiary amine, respectively. Like ammonia, the amines are weak bases because the unshared electron pair of the nitrogen atom can form a coordinate bond with a proton (see chemical bond). Amines will react with a mineral acid to form an amine salt, e.g., with hydrochloric acid to form an amine hydrochloride. A water-insoluble amine can be made to dissolve by adding acid to form its water-soluble amine salt. Amines react similarly with alkyl halides to form alkyl ammonium salts. Amines can be synthesized by reacting ammonia with an alkyl halide and neutralizing the resulting alkyl ammonium salt with an alkali, e.g., sodium hydroxide. This procedure yields a mixture of primary, secondary, and tertiary amines that is easily separated into its three components by fractional distillation. Amines can also be prepared by the reaction of ammonia with an alcohol or by the reduction of any of a variety of compounds containing nitrogen in a higher oxidation state. Amines take part in many kinds of chemical reactions; in particular, they can react with an acid chloride, acid anhydride, or ester to form an amide. All reactions of amines involve bonding of an electron-deficient atom to the amino nitrogen through its unshared electron pair. One of the most important amines is aniline, an aromatic amine.

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"amino group." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 10 Dec. 2017 <http://www.encyclopedia.com>.

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amino group

amino group Chemically the CH—NH2 group of amino acids and amines, among other compounds. The amino acid lysine has a second amino group in its side‐chain.

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"amino group." A Dictionary of Food and Nutrition. . Encyclopedia.com. 10 Dec. 2017 <http://www.encyclopedia.com>.

"amino group." A Dictionary of Food and Nutrition. . Encyclopedia.com. (December 10, 2017). http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/amino-group

"amino group." A Dictionary of Food and Nutrition. . Retrieved December 10, 2017 from Encyclopedia.com: http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/amino-group

amino group

amino group The chemical group −NH2.

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"amino group." A Dictionary of Earth Sciences. . Encyclopedia.com. 10 Dec. 2017 <http://www.encyclopedia.com>.

"amino group." A Dictionary of Earth Sciences. . Encyclopedia.com. (December 10, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amino-group

"amino group." A Dictionary of Earth Sciences. . Retrieved December 10, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amino-group

amino group

amino group The radical group-NH2.

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"amino group." A Dictionary of Plant Sciences. . Encyclopedia.com. 10 Dec. 2017 <http://www.encyclopedia.com>.

"amino group." A Dictionary of Plant Sciences. . Encyclopedia.com. (December 10, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amino-group-0

"amino group." A Dictionary of Plant Sciences. . Retrieved December 10, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amino-group-0

amino group

amino group The radical group NH2.

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"amino group." A Dictionary of Zoology. . Encyclopedia.com. 10 Dec. 2017 <http://www.encyclopedia.com>.

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"amino group." A Dictionary of Zoology. . Retrieved December 10, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amino-group-1