Calcium picrate

In a French factory streaks of Picric Acid had been formed alongside a narrow gauge railway. As the soil beneath was calcareous, calcium picrate formed which, having dried up in the summer, was ignited by friction or a blow, spreading flames all over those parts of the factory marked with calcium picrate streaks ... 

Trimethyldecahydroquinolinium picrate, 3765 Ammonium picrate, 2322 Calcium picrate, 3430 Cobalt(II) picramate, 3460 Copper(II) picrate, 3432 Lanthanum picrate, 3741 Lead(II) picrate, 3436 Manganese picrate hydroxide, 3742 Mercury(II) picrate, 3433 S-7-Methylnonylthiouronium picrate, 3737 Nickel picrate, 3435 Potassium picrate, 2085 Sodium picrate, 2086 Zinc picrate, 3437... 

Ammonium picrate, 2315 Calcium picrate, 3424 Cobalt(II) picramate, 3454 Copper(II) picrate, 3426 Lanthanum picrate, 3735 Lead(II) picrate, 3430 Manganese picrate hydroxide, 3736 Mercury(II) picrate, 3427 5-7-Methylnonylthiouronium picrate, 3731 Nickel picrate, 3429... 

The Americans preferred to use calcium picrate instead of the sparingly soluble picric acid, proceeding in the following manner ... 

A paste of chloride of lime was first prepared and pumped into a vertical vessel of enamelled iron where it was mixed with calcium picrate prepared previously by mixing picric acid with water and an excess of lime. The mixture was allowed to react at ordinary temperatures for about 2 hours and then a current of steam was introduced at the bottom of the vessel. In these conditions the rise in temperature accelerated the reaction and at 85° C. the chloropicrin began to distil. Distillation was continued until no more chloropicrin came over. 

Fig. 30. Structure of the benzo[]5]crown>5 complex with calcium picrate and three water molecules "W . Hydrogen atoms have bera omitted for clarity...

C12H4CaNsOi4 5 H2O, Calcium picrate pentahydrate, 45B, 73 C12H8AUKN4, Potassium dicyanoaurate(I) 2,2 -bipyridyl, 46B, 228 Cl2H12MgN20e, Magnesium picolinate dihydrate, 39B, 516 Cl2H1sNa04, (1-Phenylbutane-1,3-dionato)(ethylene glycol)sodium,... 

William McPherson, Report of the Director of Outside Plants, Enclosure 3 (Stamford), pp. 1-5, NARA, RG 175, entry 8, box 14 on chlorpicrin, see Crowell, America s Munitions, 1917-1918, 400. Crowell points out that later plants used calcium picrate rather than picric acid. 

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