Reactions Involving Nitrogen

There are similar reactions involving nitrogen analogs called imine anions. The alkylated imines can be hydrolyzed to the corresponding ketone, and this reaction is discussed in Section 1.3. 

Fig. 4.2 Comparison of amino acid yields using CH4, CO and CO2 as carbon sources with the addition of varying amounts of H2. The yields were calculated on the basis of the amount of carbon present in the reaction mixture. In all cases, the partial pressures of nitrogen, methane, carbon monoxide and carbon dioxide were lOOmmHg. For the reactions using nitrogen, the reaction vessel contained 100 mL of water, but no ammonia. Reactions involving nitrogen and ammonia were carried out using 100 mL of ammonium chloride (0.05 M). The electrical discharge experiments took 48 hours at room temperature (Schlesinger and Miller, 1983)...

In the early 1950 s, it was reported by Haagen-Smit that many of the characteristics of photochemical smog could be explained by the presence of ozone and other photochemical oxidants. These substances, he believed, were formed in the atmosphere as a result of chemical reactions involving nitrogen oxides and hydrocarbons present in automobile exhaust. Significant quantities of nitrogen oxides were also emitted by power plants. 

Many kinds of replacement reactions involve nitrogen compounds. A good many of these processes, described in the following sections, utilize diazonium salts. 

The kinetics of the formation of surface nitride layers are discussed in terms of a reaction involving nitrogen-hydrogen molecular ions with the substrate. Diffusion of nitrogen into the bulk determines the rate of growth of the nitride layer. 

The amination of aryl halides and triflates catalyzed by palladium complexes is suitable for use in complex synthetic problems. Many substrates will produce high yields of mixed arylamines with one of the existing catalyst systems. Nevertheless, there are many combinations of substrates for which the amination chemistry may be substantially improved. For the most part, these reactions involve nitrogen centers, such as those in pyrroles, indoles, amides, imidazoles and other heterocyclic groups that are less basic than those in standard alkylamines. Although mild reaction conditions have been developed for many substrates, the harsh conditions used in many of the applications indicate that continued studies on developing mild condi-... 

Equation (42) cannot be used if NO concentrations approach their equilibrium values, since the net production rate then depends on the concentration of NO, thereby bringing bivariate probability-density functions into equation (40). Also, if reactions involving nitrogen in fuel molecules are important, then much more involved considerations of chemical kinetics are needed. Processes of soot production similarly introduce complicated chemical kinetics. However, it may be possible to characterize these complex processes in terms of a small number of rate processes, with rates dependent on concentrations of major species and temperature, in such a way that a function w (Z) can be identified for soot production. Rates of soot-particle production in turbulent diffusion flames would then readily be calculable, but in regions where soot-particle growth or burnup is important as well, it would appear that at least a bivariate probability-density function should be considered in attempting to calculate the net rate of change of soot concentration. 

Nitrogen Oxide. The photochemical smog reaction involves nitrogen oxides, hydrocarbons, and sunlight. The global importance of this pollutant system depends upon the amounts of materials emitted to the atmosphere, their residence time in the atmosphere, and their reaction products. 

Figure 12 Major reduction-oxidation reactions involving nitrogen. The reactions are numbered as follows (1) mineralization, (2) ammonium assimilation, (3) nitrification, (4) assimilatory or dissimilatory nitrate reduction, (5) ammonium oxidation, (6) nitrite oxidation, (7) assimilatory or dissimilatory nitrate reduction, (8) assimilatory or dissimilatory nitrite reduction, (9) denitrification, (10) chemodenitrification, (11) anaerobic ammonium oxidation, and (12) dinitrogen fixation (after Capone, 1991) (reproduced by permission of ASM Press from Microbial Production and Consumption of Greenhouse Gases Methane, Nitrogen Oxides, and Halomethanes, 1991).

There is another set of reactions in which pyridine acts as a base or nucleophile these reactions involve nitrogen directly and arc due to its unshared pair of electrons. 

Reactions involving nitrogen oxides (NO and N02) and ozone (03) lie at the heart of... 

Several enzymatic reactions involving nitrogenous compounds also occur post-mortem in fish muscle. They have been overlooked until recently... 

Figure 13.7. Major functionalization reactions involving nitrogen atoms in substrate molecules. The reactions shown here are mainly oxidations (oxygenations and dehydrogenations) and reductions (deoxygenationsand hydrogenations).

The study of physical equilibrium yields useful information, such as the equilibrium vapor pressure (see Section 11.8). However, chemists are particularly interested in chemical equilibrium processes, such as the reversible reaction involving nitrogen dioxide (NO2) and dinitrogen tetroxide (N2O4) (Figure 14.1). The progress of the reaction... 

Figure 9-6 summarizes our current understanding of the chemical reactions involving nitrogen oxides in the troposphere. Photolytically induced... 

Table 9-10. Reactions Involving Nitrogen Oxides and Their Oxidation Products 1...

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