Hydrogen of ammonia

The small differences m basicity between ammonia and alkylammes and among the various classes of alkylammes (primary secondary tertiary) come from a mix of effects Replacing hydrogens of ammonia by alkyl groups affects both sides of the acid-base equilibrium m ways that largely cancel... 

Very little positive charge is present at the hydrogens of ammonia (pKa = 38). 

Under special conditions, the hydrogen directly attached to the phosphorus atom may have acidic properties, in the same way that the hydrogen of ammonia can be replaced by other radicles. Two isomeric triethyl phosphites have been prepared, by R. Railton, C. Zimmermann,. A. E. Arbusofi, T. E. Thorpe and B. North and by A. Michaelis and co-workers. The one obtained by the action of sodium ethoxide on phosphorus trichloride is supposed to be constituted P(OC2H6)3, in accord with the equation ... 

If the hydrogens of ammonia are replaced by alkyl or aryl groups, amines result. Depending on the number of carbon atoms bonded directly to nitrogen, amines are classified as either primary (one carbon atom), secondary (two carbon atoms), or tertiary (three carbon atoms) (Table 33.1). 

Amines are a series of compounds containing carbon, hydrogen and nitrogen. They are part of the building blocks for the important protein molecules involved in metabolic processes. Amines are compounds similar to ammonia, but have one or more of their hydrogens replaced by a carbon chain, e.g. CH3. When one hydrogen of ammonia is replaced, the series is called the primary amines (Figure 5.1) with two Hs replaced, the series is called the secondary amines, and with all three replaced, tertiary amines. 

Phenyl Nitroso Hydroxyl Amine.— Phenyl hydroxyk amine is a secondary amine, one hydrogen of ammonia being replaced by the phenyl group and another by the hydroxyl group. With nitrous acid, therefore, it acts as secondary amines do, yielding a nitroso amine... 

Amines are compounds in which one or more of the hydrogens of ammonia have been replaced by alkyl groups. Smaller amines are characterized by their fishy odors. Fermented shark, for example, a traditional dish in Iceland, smells exactly like trieth-ylamine. There are primary amines, secondary amines, and tertiary amines. The classification depends on how many alkyl groups are bonded to the nitrogen. Primary amines have one alkyl group bonded to the nitrogen, secondary amines have two, and tertiary amines have three. 

In Section 2.7, we saw that amines are classified as primary, secondary, or tertiary, depending on whether one, two, or three hydrogens of ammonia, respectively, have been replaced by an alkyl group. We also saw that amines have both common and systematic names. Common names are obtained by citing the names of the alkyl subsitutents... 

These substances are derivable from benzene and its homo-logues by the substitution of one or more univalent groups (NHj) radical phenyl (CeHj), or its homologues, derivable from the benzene nucleus, for the hydrogen of ammonia. They all are strongly basic in character. 

The 8+ carbon will attract the lone pair on the 8 nitrogen of ammonia. At the same time, the S oxygen will attract a 8+ hydrogen of ammonia. 

Amines are compounds in which one or more of the hydrogens of ammonia (NH3) are replaced by an alkyl group ... 

Primary amines have one hydrogen of ammonia replaced with a carbon in the form of an allg l or aryl group. 

Amines are commonly named as alkyl derivatives. Thus, the series in which the hydrogens of ammonia (NH3) are replaced by, for example, mer/iyZ groups would be called, respectively, methanamine (methylamine,CH3NH2), A-methylmethanamine (dimethylamine, (CH3)2NH), and A,A-dimethylmethanamine (trimethylamine, (CH3)3N). The positively charged species corresponding to the ammonium cation would thus be the tetramethylammonium cation [(CH3)4N+],... 

Amines, compounds in which one or more of the hydrogens of ammonia (NH3) have been replaced by an alkyl group, are among some of the most abundant compounds in the biological world. We will come to appreciate their biological importance as we explore the stmctures and properties of amino acids and proteins in Chapter 22 as we study how enzymes catalyze reactions in Chapter 23 as we investigate the ways in which coenzymes—compounds derived from vitamins—help enzymes catalyze reactions in Chapter 24 and as we learn about nucleic acids (DNA and RNA) in Chapter 26. 

Amines are classified as primary, secondary, or tertiary, depending on whether one, two, or three hydrogens of ammonia have been replaced by alkyl groups. 

Pre-reduction with hydrogen of ammonia synthesis catalysts. (American Cyanamid Co.). US 3787335 (1974). 

When an organic compound contains the group NH2, it is not necessarily basic in nature in fact it may be basic, neutral, or even acidic, the structure of that part of the molecule united to the NHo group exerting the controlling influence. When a hydrogen of ammonia is substituted by an alkyl or related radical, we obtain a primary amine which compares favorably with ammonia in basicity. 

When the second and third hydrogens of ammonia are replaced by alkyl radicals, we find that the resulting secondary and tertiary amines are of approximately the same order of basicity as the primary amines. (See second column of Table IX.)... 

In MejNH, two of the hydrogens of ammonia have been replaced by methyl groups—again, we can look at the structure as either a substituted methane or a substituted ammonia. The bond angles at nitrogen, according to VSEPR, will be about 107 °. 

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