Salts of Dinitroresorcinol

Lead picrate forms several basic salts with varying lead content. They form citric yellow crystals practically insoluble in water or alcohol. Its explosive properties are similar to those of lead styphnate but its flammability is lower [10]. Sensitivity to electrostatic discharge is high (at the level of LS) and is the reason for the many accidents which occurred during its manufacture [12]. Sensitivity to impact is 2.5 J (it explodes by 5 kg hammer from 5 cm) [13]. 

Basic lead picrate is prepared by reaction of picric acid with yellow lead oxide in water. The mixture is stirred and boiled during the reaction. Product forms as a precipitate [11]. Basic lead picrate has similar explosive properties to those of LS and was therefore used in similar applications (e.g., as a component of percussion mixtures) [10-12]. Due to its lower flammability, it was, however, replaced in practical use by LS [12]. 

Dinitroresorcine (DNR) forms two isomers 2,4 and 4,6. Unlike in the nitration of some other aromatic molecules (toluene, phenol), it is possible to prepare practically pure dinitro isomers. The position of nitro groups in the ring depends on the reaction conditimis. The 2,4-isomer of DNR can be easily prepared by dinitrosatimi of resorcinol followed by alkaline oxidation of 2,4-dinitrosoresorcinol [8,14]. 2,4-DNR cannot be prepared by sulfonation of resorcinol followed by reaction with nitric acid (method used for phenol) because this method yields the trinitro compound. The 4,6-DNR isomer can be prepared in two ways (a) by nitration of 4,6-diacetylresorcinol and (b) directly by nitration of resorcinol using 98 % nitric acid at low temperatures (between —20 and —15 °C) [8], 

Among the various possible lead salts of DNR rally two have found industrial application as primary explosives normal lead salt of 2,4-dinitroresorcine (2,4-LDNR) and basic lead salt of 4,6-dinitroresorcine (basic 4,6-LDNR). 

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Pb or Ag salt of dinitroresorcinol contg 5% of collodion as a binder, or a mixf of Pb dinitro-resorcinate 55, KC104 20, S 10, A1 powd 10 collodion 5% is used in an elec blasting cap)... 

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