Amines Organic bases derived from ammonia

Alpha-particle production a common mode of decay for radioactive nuclides in which the mass number changes. (21.1) Amine an organic base derived from ammonia in which one or more of the hydrogen atoms are replaced by organic groups. (7.6 22.4)... 

Amines are organic bases derived from ammonia. 

Besides water, the most common weak base is ammonia, NH3, whose proton transfer equilibrium with water appears in Section 16-. Many other weak bases are derivatives of ammonia called amines, hi these organic compounds, one, two, or three of the N—H bonds in ammonia have been replaced with N—C bonds. The nitrogen atom in an amine, like its counterpart in ammonia, has a lone pair of electrons that can form a bond to a proton. Water does not protonate an amine to an appreciable extent, so all amines are weak bases. Table 17-4 lists several examples of bases derived from ammonia. 

Amine o- men, a- men [ISR, fr. NL ammonia] (1863) n. Organic bases derived from the parent compound, ammonia (NH3). The hydrogens of the ammonia may be substituted by alkyl groups, in which case the series of aliphatic bases is produced. Similarly, aromatic bases are formed when... 

Organic derivatives of ammonia are called amines. Because nitrogen is trivalent, amines can be primary (attached to one carbon), secondary (attached to two carbons), or tertiary. All amines are basic, and their strength as bases increases with the number of alkyl groups attached to the nitrogen that is, methyl amine is a stronger base than ammonia and trimethylamine is stronger than dimethylamine. Amines can be prepared from ammonia and an alkyl halide ... 

Just as ammonia, NH3, is a weak base, there are a large number of nitro-gen-containii organic compounds called amines that are also weak bases. In the early days of organic chemistry, basic amines derived from natural sources were known as vegetable alkali, but they are now referred to as alkaloids. The study of alkaloids provided much of the impetus for the growth of organic chemistry in the nineteenth century, and it remains today a fascinating area of research. 

Figure 18.10 Abstraction of a proton from water by methylamine. The amines are organic derivatives of ammonia. Methylamine, the simplest amine, acts as a base in water by accepting a proton, thereby increasing [OH l.

A variety of factors contribute to the lone pair on the nitro n being more or less available. The pKa value for a base is derived from the equilibrium between the forms of the base shown in Figure 3.3 for a secondary amine in water where Kb is the equilibrium constant. In water, the equilibrium for nitrogen-containing bases lies well to the left and, for instance, in ammonia solution (Kb =1.8 x 10 ) in water only 0.0018% of the ammonia is protonated. Organic bases become increasingly water insoluble as the size of the... 

Ammonia. Although ammonia is not an organic chemical, it is one of the largest-volume synthetic petrochemicals. From it many reactive organic chemicals are derived such as urea, acrylonitrile, caprolactam, amines, and isocyanates. Almost all of the 40.6 or more billion lb of ammonia produced in 1999 in the United States was based on hydrogen from petroleum and natural gas. Detailed descriptions of ammonia processes are found in Chapter 29. 

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