2.4.6- trinitrotoluene isomers

TNT was first prepared in 1863 by Wilbrand and its isomers discovered in 1870 by Beilstein and Kuhlberg. Pure TNT (2,4,6-trinitrotoluene isomer) was prepared by Hepp in 1880 and its structure determined by Claus and Becker in 1883. The development of TNT throughout the 19th and 20th centuries is summarized in Table 2.11. 

Ref C. Ribaudo J. Haberman, Origin— Identification of Explosives Via Their Composite Impurity Profiles, I, The Relation of the Origin of Military Grade TNT to its Mono-, Di-, and Trinitrotoluene Isomer Impurities , PATR 4768 (1975)... 

The trinitrotoluene isomers follow the same trends, invoking dinitro steric interactions and favorable solid lattice energies, as the dinitrotoluenes. 

Ref 6) and Clift Fedoroff (Ref 7) described prepn of MeTetryl from beta- and gamma-Trinitrotoluene isomers always present as impurities on the surface of crysts of etude aipha-TNT. The jS and y isomers can be removed by washing the crysts of crude a TNT with 8% aqueous Na sulfite soln (called Sellite). This converts the isomers into water-soluble dinitrotoluene sulfonates. Then, on their treatment with me thy famine the following reaction takes place ... 

Pristera, Preparation and Physical Properties of Di- and Trinitrotoluene Isomers , PATR 2525... 

The low melting point of a- trinitrotoluene is due mainly to the presence of trinitrotoluene isomers, and to a lesser degree, to the presence of other impurities, such as trinitrobenzene, trinitrocresol, dinitrotoluene. 

Since the trinitrotoluene isomers are formed as a result of the nitration of m- ni-trotoluene, W. W. Jones and Russel [9] undertook the task of determining to what extent the presence of m- nitrotoluene in mononitrotoluene lowers the melting point of a- nitrotoluene. The authors nitrated mixtures of m- and p- nitrotoluenes (Table 61). 

T. Urbanski and Gedroyc [93] prepared dinitrophenylnitromethane (I) -a trinitrotoluene isomer - by nitration of phenylnitromethane. The compound has proved to have explosive properties similar to those of TNT. 

The values of the nitro-, dirdtro- and trinitrotoluene isomers and of some oxidation and reduction products of a-(2,4,6-)trinitro-toluene (= 8t) are referred to this last named compound. Ethyl acetate-petrol ether (15 + 85) and 1,2-dichloroethane-petrol ether (25 + 75) were the solvents used in the 1st and 2nd directions respectively. The-substances were visualised by spraying with the 4-diethylaminobenz-aldehyde reagent, yielding yellow, brown or red spots (Fig. 187). 

Mixtures of HNO, H2SO4, and SO also result in high concentrations of NO/, and toluene can be readily nitrated at —40 to — 10°C as a result (6). At these low temperatures, the formation of the meta-isomer of mononitrotoluene (MNT) is greatiy reduced. Such a reduction is highly desired in the production both of dinitrotoluenes (DNTs) employed to produce intermediates for polyurethane production and of trinitrotoluene (TNT), which is a high explosive. > -MNT results in the production of undesired DNT and TNT isomers (see Nitrobenzene and nitrotoluenes). 

Organic Reactions. Nitric acid is used extensively ia iadustry to nitrate aHphatic and aromatic compounds (21). In many iastances nitration requires the use of sulfuric acid as a dehydrating agent or catalyst the extent of nitration achieved depends on the concentration of nitric and sulfuric acids used. This is of iadustrial importance ia the manufacture of nitrobenzene and dinitrotoluene, which are iatermediates ia the manufacture of polyurethanes. Trinitrotoluene (TNT) is an explosive. Various isomers of mononitrotoluene are used to make optical brighteners, herbicides (qv), and iasecticides. Such nitrations are generally attributed to the presence of the nitronium ion, NO2, the concentration of which iacreases with acid strength (see Nitration). 

The flash photolysis-of 2,4,6-trinitrotoluene solns (TNT) indicated a photochemically induced isomerization leading to the aci-quinoid isomer... 

The trinitrotoluene is separated from the mother liquor, washed with w, and then treated with a sulfite soln called Sellite which extracts undesirable isomers and impurities, leaving purified a-TNT. The TNT is washed, solidified, flaked, and finally shipped out in boxes... 

Red Water — which can be almost black at times - also contains dissolved TNT however, it is not an incidental stream like Pink Water it is a major by-product stream from TNT manuf. The mixed-acid nitration of toluene yields not only 2,4,6-trinitrotoluene, the desired product, but also a host of other isomers and by-products amounting to approx 4.5% of the total yield and it is necessary to remove them from the product. They are removed by extraction with a Na sulfite—Na carbonate soln which sulfonates and dissolves them the extract is called Red Water. Red Water is a very complex and somewhat variable mixt containing 15% or so of sulfonated or sellited nitrobodies and a number of inorganic salts. Typical components are w, NajSOj—NaS04, NaN02— NaNOj, sulfonated or... 

Seliwanoff s test analy chem A color test helpful in the identification of ketoses, which develop a red color with resorcinol in hydrochloric acid. s3 liv3,nofs, test sellite liNORG chem A solution of sodium sulfite (Na2S03) used in the purification of 2,4,6-trinitrotoluene to remove unsymmetrical isomers. se,lTt ... 

The by-products of industrial TNT, including isomers of trinitrotoluene, dinitrotoluene, trinitrobenzene and dinitrobenzene, were investigated using LC/ MS-APCI in the negative-ion mode to build a profile for the characterization of TNT samples from various origins [21], MS/MS-CID was used for further identification of some of the nitroaromatic isomers. 

The reactivity of nitro groups positioned olp- to other nitro groups has implications for the use of other polynitroarylenes as explosives. For example, of the numerous possible isomers of trinitrotoluene, only the symmetrical 2,4,6-isomer (a-TNT) is chemically stable enough for use as an explosive. Only in the case of the 2,4,6-isomer are the three nitro groups positioned m- to one another all other isomers of trinitrotoluene contain either one or two nitro group in... 

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