picric acid(redirected from nitroxanthic acid)
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picric acid(pĭk`rĭk) or
2,4,6-trinitrophenol(trī'nī'trōfē`nōl), C6H2(NO2)3OH, a toxic yellow crystalline solid that melts at 122°C; and is soluble in most organic solvents. Picric acid is a derivative of phenolphenol
, C6H5OH, a colorless, crystalline solid that melts at about 41°C;, boils at 182°C;, and is soluble in ethanol and ether and somewhat soluble in water. An aromatic alcohol, it exhibits weak acidic properties and is corrosive and poisonous.
..... Click the link for more information. . It reacts with metals to form metal picrates, which like picric acid itself are highly sensitive explosivesexplosive,
substance that undergoes decomposition or combustion with great rapidity, evolving much heat and producing a large volume of gas. The reaction products fill a much greater volume than that occupied by the original material and exert an enormous pressure, which can be
..... Click the link for more information. that can be detonated by heat, flame, shock, or friction. The high explosives lyddite and melinite are composed mostly of compressed or fused picric acid. Picric acid is often used as a booster to detonate another, less sensitive explosive, such as TNT (trinitrotoluenetrinitrotoluene
, CH3C6H2(NO2)3, crystalline, aromatic compound that melts at 81°C;. It is prepared by the nitration of toluene.
..... Click the link for more information. ). Although picric acid can be synthesized by nitration of phenol, higher yields are obtained if chlorobenzene is used as a starting material; the latter method involves several steps and the formation of several intermediate products. In addition to its use in explosives, picric acid has been used as a yellow dye, as an antiseptic, and in the synthesis of chloropicrin, or nitrotrichloromethane, CCl3NO2, a powerful insecticide.
(or trinitrophenol), an aromatic nitro compound; it is a high explosive whose properties are similar to those of trinitrotoluene. Pour point, 129°C.
In the first quarter of the 20th century, picric acid was used in ammunition. However, its use has been limited because of the high mechanical sensitivity of its metal salts, which form readily (seePICRATES). Trinitrophenol is obtained by the nitration of phe-noldisulfonic acid using a mixture of nitric and sulfuric acids. It is also obtained from dinitrochlorobenzene, with dinitrophenol as an intermediate, and from benzene under the action of nitric acid and Hg(NO3)2.