Collier's New Encyclopedia (1921)/Trinitrotoluenes

TRINITROTOLUENES, substances formed by the nitration of toluene, having the general formula CaH2CH3(N02)3. There are three compounds of this name, all having the same chemical constitution, but differing in the arrangement of the nitro groups in the molecule. These three are known respectively as A, B, and T trinitrotoluene. The most important of the three is A or symmetrical trinitrotoluene, which forms the constituent of the explosive well known as T. N. T. B and T trinitrotoluene, when fused with sodium sulphide and sulphur, yield dyes which give a deep khaki-brown shade. Most of the T. N. T. used for explosive purposes contains small amounts of the B and r isomers, but for some purposes a very pure T. N. T. is required, and this is produced by recrystallizing the crude product from various solvents such as alcohol, benzene or a mixture of the two. The nitration of toluene can be carried out in two stages or in three. In the three-stage process, mono-nitrotoluene is first produced by nitrating toluene with a comparatively weak solution of mixed nitric and sulphuric acids. From this, by further nitration, dinitrotoluene is pro- duced, and finally by treating the dinitrotoluene with strong mixed acids, trinitrotoluene is produced. By the two-stage process, mononitrotoluene is first produced, as above, and then converted direct to trinitrotoluene by treatment with strong mixed acids. A one-stage process has been tried, but is viewed with disfavor, owing to the danger of introducing strong acid direct into toluene. See Explosives.