Nitrogen common compounds

Substrates. Many different types of nitrogen-containing compounds can be hydrogenated to amines, but nitro compounds and nitriles are the most commonly used starting materials. 

Hantzsch 2 gave the name pseudo bases to those carbinols that gave salts with acids by the elimination of water and a simultaneous change of constitution. Such carbinols are common among the nitrogen heterocyclic compounds and the naturally occurring alkaloids e.g., berberine, sanguinarine, chelerythrine. 

The most common selective detectors in use generally respond to the presence of a characteristic element or group in the eluted compound. This is well illustrated by the thermionic ionisation detector (TID) which is essentially a flame ionisation detector giving a selective response to phosphorus- and/or nitrogen-containing compounds. Typically the TID contains an electrically heated rubidium silicate bead situated a few millimetres above the detector jet tip and below the collector electrode. The temperature of the bead is maintained... 

Table 11.2 15N chemical shifts of some common nitrogen-bearing compounds... 

The most common compound of carbon and nitrogen is cyanogen, (CN)2. The cyanide ion, CN , is a pseudohalide ion, which means that it resembles a halide ion because it forms an insoluble silver compound and it can be oxidized to the X2 species. Cyanogen was first obtained by Gay-Lussac in 1815 by heating heavy-metal cyanides. 

Amines are nitrogen-containing compounds found in all meteorites that contain amino acids. Their abundances are comparable to those of amino acids, and abundances decrease with increasing numbers of carbon atoms. Similarities between amines and amino acids in the same meteorite have led to the suggestion that amines formed from the amino acids by decarboxylation (loss of the carboxylic acid functional group). This process commonly occurs on heating. 

Figure 11.5—Comparative diagram showing the most common transitions in simple oxygen or nitrogen-containing compounds. These four types of transitions are often shown on a single energy diagram to indicate their relative position, or to indicate the spectral regions involved.

The basic monomers of nucleic acids are nucleotides which are made up of heterocyclic nitrogen-containing compounds, purines and pyrimidines, linked to pentose sugars. There are two types of nucleic acids and these can be distinguished on the basis of the sugar moiety of the molecule, Ribonucleic acids (RNA) contain ribose, while deoxyribonucleic acid (DNA) contains deoxyribose. The bases cytosine (C) adenine (A) and guanine (G) are common in both RNA and DNA. However, RNA molecules contain a unique base, uracil (U), while the unique DNA base is thymidine (T). These differences in the base structure markedly affect the secondary structures of these polymers. The structures of DNA and RNA are outlined in Appendix 5.2. 

Farmers often need to add substances containing these nitrates. Such substances include farmyard manure and artificial fertilisers. One of the most commonly used artificial fertilisers is ammonium nitrate, which as you saw earlier is made from ammonia gas and nitric acid, both nitrogen-containing compounds. 

Base Nitrogen-containing compounds that are parts of the nucleotides that make up nucleic acids. The most common bases are adenine (A), cytosine (C), guanine (G), thymine (T) and uracil (U). 

Nitrogen, the first element in Group V, has a chemistry sufficiently complex and interesting so that it can profitably be studied apart from the remainder of the group. In essentially all of its common compounds (except for the metallic nitrides), nitrogen is bonded covalently to carbon, oxygen, or hydrogen or to combinations of these three elements. 

Nitrogen is another element often found in the functional groups of organic compounds. The most common nitrogenous organic compounds are amines, amides, and nitriles. 

Note The nitrogen-phosphorus detector responds to nitrogen-phosphorus compounds about 100 000 times more strongly than normal hydrocarbons. Due to this high degree of selectivity, the NPD is commonly used to detect pesticides, herbicides, and drags. 

The most common and important nitrogen-hydrogen compound is ammonia. Because liquid ammonia is a commonly used nonaqueous solvent, it was discussed in Section 5.2.3 and its properties are listed in Table 5.5. Approximately 22 billion pounds of NH3 are used annually, mostly as fertilizer or as the starting material for preparing nitric acid. The Haber process is used for the synthesis of NH3 from the elements ... 

A considerable number of sulfur-nitrogen compounds exist, and some of them have unusual properties. The most common compound of this type is S4N4, tetrasulfur tetranitride. The compound can be prepared by the following reaction ... 

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