Aromatic nitro compounds table

A number of selected aromatic nitro compounds are collected in Table IV,16A, It will be noted that a few nitro aromatic esters have been included in the Table. These are given here because the nitro group may be the first functional group to be identified aromatic nitro esters should be treated as other esters and hydrolysed for final identification. 

TABLE 29. MM2 and MM2 calculated gas-phase heats of formation for aliphatic and aromatic nitro compounds... 

The melting points of some symmetrical aromatic azo compounds, prepared from the corresponding aromatic nitro compounds, are given in Table VII. 

GSH may also be coupled to electrophilic reaction intermediates nonenzymatically or by GSH transferase (GST)-catalyzed reactions. Many different types of substrates will undergo GSH conjugation, including epoxides, halogenated compounds, aromatic nitro compounds, and many others. In these reactions, GSH can interact with an electrophilic carbon or heteroatom (O, N, and S) [35]. One such substrate is a reactive metabolite of acetaminophen (APAP), N-acetyl-p-benzoquinonimine (NAPQI), which will readily form a GSH conjugate (Scheme 3.2). Other examples of Phase II bioactivation reactions that lead to toxic endpoints are shown in Table 3.1. 

The impurities present in aromatic nitro compounds depend on the aromatic portion of the molecule. Thus, benzene, phenols or anilines are probable impurities in nitrobenzene, nitrophenols and nitroanilines, respectively. Purification should be carried out accordingly. Isomeric compounds are likely to remain as impurities after the preliminary purifications to remove basic and acidic contaminants. For example, o-nitrophenol may be found in samples of p-nitrophenol. Usually, the o-nitro compounds are more steam volatile than the p-nitro isomers, and can be separated in this way. Polynitro impurities in mononitro compounds can be readily removed because of their relatively lower solubilities in solvents. With acidic or basic nitro compounds which cannot be separated in the above manner, advantage may be taken of their differences in pKg values. The compounds can thus be purified by preliminary extractions with several sets of aqueous buffers of known pH (see for example Table 19, p. 43) from a solution of the substance in a suitable solvent such as ethyl ether. This method is more satisfactory and less laborious the larger the difference between the pK value of the impurity and the desired compound. Heterocyclic nitro compounds require similar treatment to the nitroanilines. Neutral nitro compounds can be steam distilled. 

Nitroglycerine is toxic to handle, causes headaches, and yields toxic products on detonation. It is insoluble in water but readily dissolves in most organic solvents and in a large number of aromatic nitro compounds, and forms a gel with nitrocellulose. The acid-free product is very stable, but exceedingly sensitive to impact. Some of the properties of nitroglycerine are presented in Table 2.7. 

Other reagents that have been used to reduce support-bound aromatic nitro compounds include phenylhydrazine at high temperatures (Entry 5, Table 10.12), sodium borohydride in the presence of copper(II) acetylacetonate [100], chromium(II) chloride [196], Mn(0)/TMSCl/CrCl2 [197], lithium aluminum hydride (Entry 3, Table... 

Many pesticides are suitable for reductive LCEC. Examples are listed in Table 1. The reduction of aromatic nitro compounds has been widely studied (59). Mononitroaromatic compounds are reduced to hydroxylamines in a four-electron process (see below). 

Table 3. Relative response factors for aromatic nitro compounds and nitrosamine for the...

At sufficiently high temperatures, the detector also responds to a variety of nitroaro-matics and to (V-nitrosodimethylamine. NOz yields of 0.70 and 0.90 were obtained for 2,4-DNT and TNT, respectively. The detection system exhibits a linear response for all nitrogen-containing compounds studied, and the detection limit for the determination of organic nitrates was found to be 0.05pmol. The relative response factors for aromatic nitro compounds and nitrosamine for the pyrolyser/luminol detector are presented in Table 3. 

It is interesting to note that ranging from non-polar solvents to sulphuric acid through polar solvents affects aromatic nitro compounds in the opposite direction, i.e. it results in a bathochromic shift. This can be seen from Hammond Mid Mo-die s data [15] for nitrobenzene (Table 22). 

T. Urbanski, Piskorz, Maciejewski and Cetner [59] investigated the properties of stoichiometric mixtures of tetranitromethane with benzene and with aromatic nitro compounds. The results obtained are tabulated below (Table 130). 

Iridium,204,205 together with osmium, has been not widely used in catalytic hydrogenation. Recently, however, iridium or iridium-based catalysts have been shown to be effective in various hydrogenations, such as in selective hydrogenation of a,P-unsaturated aldehydes to allylic alcohols (Section 5.2), of aromatic nitro compounds to the corresponding hydroxylamines (Section 9.3.6), of halonitrobenzenes to haloanilines without loss of halogen (Section 9.3.2), and in the stereoselective hydrogenation of carbon to carbon double bonds (see, e.g., eqs. 3.25-3.27 and Table... 

Steric influence was also referred to NO2 deformation and C—N stretching vibrations in aromatic nitro compounds by Nakamura and co workers [31]. They examined aromatic nitro compounds containing halogen substituents in various positions. They found (as anticipated) that ortho substitution lowered NOjabending and deformation modes owing to steric hindrance. This can be seen from Table 20. 

Andreev and Kaidymov [134) published a teview on the thermal decomposition of FETN and a description of their own results. Their data for activation energy are given in Table 47. Tliey confirmed the results of T. Urbanski and co-workers (Vol. II, pp. 181-183) and similarly of Tonegutti [135) and Bourjol (136) that the addition of aromatic nitro compounds to PETN lowers [the stability of the latter. In all experiments it was shown that decomposition in Jthe liquid phase, that is, the molten system, engenders faster decomposition than [that of the solid phase. 

A very prominent effect is of solvent upon the ir — tr aromatic band in aromatic nitro compounds. When given spectra of organic compounds, thought should be given to the solvent used. This is particularly important in the ultraviolet region. Schubert and Robins [24] give some figures for nitrobenzene in some common solvents - Table 16. 

Whereas trinuclear iron clusters have been used in stoichiometric reduction of aromatic nitro compounds, the tetranuclear iron cluster Cp4Fe4(CO)4 can be used for the catalytic hydrogenation of nitrobenzene to aniline [Table IV (92,96,113-116)]. 

In the following sections the quantified occurrence of specific riverine contaminants including their mode of association is discussed in detail for the Teltow Canal sediments investigated. The contaminants determined were attributed to halogenated aromatics, nitro compounds, plasticizers, technical additives and fragrances. The chemical structures are illustrated in Figure 1 and all quantitative results are presented in Tables 3 to 5. 

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