TNT

Trinotrololuene (TNT)

Trinitrotoluene(TNT)

General

Systematic name

2-methyl-1,3,5-trinitrobenzene

Molecular formula

C₇H₅N₃O₆

SMILES

CC1=C(C=C(C=C1[N+](=O)[O-])[N+](=O)[O-])[N+](=O)[O-]

Molar mass

227.131 g/mol

advised storage temperature

2-8°C

melting point

80.8°C

hazard code

F,Xn

Data are given for materials in their standard state (at 25 °C, 100 kPa)

Trinitrotoluene (TNT) is amongst the most famous explosive currently used, along with C4.

According to the IUPAC numenclature system, TNT is 2-methyl-1,3,5-trinitrobenzene, its formula is C7H5N3O6.

In 1863, TNT was synthesised for the first time by Joseph Wilbrand, yet it only reached large-scale production by 1891.

History

In 1863 Trinitrotoluene (TNT) was synthesised for the first time by Josef Wilbrand, in Germany. It's first known military use dates back to 1905 during the Russo-Japanese War. The Russians employed TNT, but eventually lost. TNT only saw large scale production in World War I by the German Navy. Thanks to its stability the German Navy, could melt it safely and use it as propellant for their artillery shells. The TNT filling allowed German shells a vastly enhanced ability to armour-piercing capacity.
By World War II, TNT had undergone several transformations, to enhance both its stability and detonation power, leading to the development of C4 and other high power explosives, nick named RDX (Research Development Explosive), in the 1960's in England mainly. TNT replaced dynamite due to its greater stability, particularly over the trinitroglycerine compound, which was much more shock sensitive. --Ajpc05 13:58, 5 December 2006 (UTC)

Synthesis

TNT is synthesised by a serie of nitration reactions. To begin with, a solution of 2:1 concentrated sulfuric acid and conecntrated nitric acid is added to toluene. The addition of NO₂ stabilises the aromatic ring, causing a drop in the reactivity of toluene. This is due to the electron-withdrawing nature of the NO₂ group. This first reaction should be carried out below 30°C, since toluene is a fairly volatile compound. Finally the excess acid (lower layer) is separated off.
The solution of mononitrotoluene is added dropwise to a solution of 2:1 concentrated sulfuric acid and conecntrated nitric acid, heated up to 50°C. The reaction is exothermic but should be kept below 100°C. The solution should be left to stir for 2 hours, and then allowed to cool down to room temperature. The lower layer (excess acid) is separated off.
A solution of 2:1 concentrated sulfuric acid and conecntrated nitric acid, with 15% petroleum and 15% SO₃, should be brought to 110°C, and kept at this temperature throughout the reaction. The Dinitrotoluene should be added dropwise to the acid solution. The solution should be left to cool down to room temperature.
The solution should be filtrated, keeping both the solids and the filtrate. The solid should be washed with water to remove remaining acid. Dissolved TNT should be extracted from the acid by washing repeatedly with hot (80-90°C) water. Upon coolin the TNT should solidify and can be filtered. The result should be pale yellow crystals.

Explosion

While TNT is a powerful explosive, it is highly stable and requires a detonator to start the reaction. Most of the power of TNT comes from the quick conversion of two moles of solid TNT to 15 moles of hot gases as per the following reaction:

2C₇H₅N₃O₆(s) → 3N₂ (g) + 7CO(g) + 5H₂O(g) + 7C(s)

This fast liberation of gas generates large amounts of heat, and causes a drastic increase in pressure in the nearby surrounding, hence the explosion. The Carbon created during the reaction gives the explosion it's dark appearance.

Reference

Wikipedia article: TNT

Anarchist Cookbook, The, 1970, William Powell