Picrate, potassium salt

If the color of flame.is. violet, the salt is fairly pure(Ref l,p 141 Ref 3,p 862). K can be identified by pptg it as K2NaCo(N02)g, as well as by potassium salts of chloro-platinate, perchlorate) acid tartrate, picrate, silicofluoride, etc(Ref 3,p 862). Various quantitative methods for detn of K ion are given in Refs 3,4,4a 8... 

Amino nicotinic acid has a molecular weight of 138.12 and crystallizes with two molecules of water from dilute acetic acid. It decomposes above 300° and is slightly soluble in most solvents. The potassium salt is freely soluble in water as is the hydrochloride. The picrate crystallizes in yellow needles which melt at 248°. This compound is prepared by treating 6-chloronicotinic acid with ammonia. 

Solutions were 2 x 10-3 mol dm-3 in compound, and potentials were determined with reference to the SCE, b Three-electron reversible oxidation process. Two-electron reversible oxidation process. Separation between anodic and cathodic peak potentials values for ferrocene under identical conditions ranged from 80 to 90 mV. Shift in respective ferrocenyl oxidation potential produced by presence of guest cation (2 equiv) added as their thiocyanate salts for potassium and ammonium, and their picrate salts for methylammonium and phenethyl-ammonium. 

Glauber, Johann Rudolph [1603 (or 1604)—1668]. Dutch (or German) "iaerochemist" [belonging to the 16th century school of medicine basedon principles of Swiss physician Paracelsus (1493— 1541)] who prepd expl substances Potassium Picrate and Ammonium Nitrate. He also prepd the salt known as "Glauber salt" (cryst Na sulfate) and pure nitric and hydrochloric acid. 

Addition of a second crown produces the loose ion pair A, Cr,K, Cr. However, the complexation constant for adding the second crown is 1800 M 1 for the fluorenyl carbanion and only 200 M 1 for the picrate salt. The lower value for picrate may in part be due to less charge delocalization, e.g., the free ion dissociation constant for potassium fluorenyl in TEF is 1.6 x 10 7M (18) as compared to 9.2 x 10 M for potassium picrate (17). The two N02 substituents close to the 0 bond in picrate may also hinder the enlargement of this ionic bond and the insertion of a crown ether molecule because of electronic or sterlc effects. 

Loose ion pairs of such charge-localized oxyanion salts as potassium t-butoxlde may be difficult to form. This alkoxide is a tetrameric aggregate in THF (20). and crown addition breaks it down to the more reactive monomeric form. It is unlikely that with benzo-15-crown-5 a 2 1 crown-K loose ion pair can be formed similar to that found with potassium picrate or potassium fluorenyl. However, external complexation itself will slightly stretch the . bond, and this can have a profound effect on the anion reactivity (21). 

As to salts, this last recipe above, taken from the literature, is the only claim of a valid hydrochloride salt of DMT. In the original synthesis, by Manske, the following description appears. "The hydrochloride could be obtained only as a pale yellow resin which, when dried in a vacuum desiccator over potassium hydroxide, became porous and brittle." I have found no attempts at its synthesis in the literature, and I have personally had no success at all. The picrate salt is well defined, used mostly for isolation and purification. The oxalate is used occasionally in animal studies. Early human studies involving the injection of solutions of the hydrochloride apparently made by dissolving DMT base in dilute aqueous HCI, and neutralizing this with base to achieve an end pH of appropriate 6. The fumarate is the salt specifically approved by the FDA for human studies, and this was the form used for human intravenous injection employed in the recent New Mexico studies. 

The new propellant was promising but the nitrocellulose smokeless powder invented soon afterwards superseded all mixtures containing potassium nitrate and similar salts, that give a number of solid particles when exploded. For a time in the United States various mixtures were still used instead of blackpowder—chiefly for sporting purposes. E.g. Gold Dust Powder (Starke [36]) consisted of 55% ammonium picrate, 25% potassium picrate and 20% ammonium bichromate. Soon, however, early in the nineteenth century, the use of these mixtures was discontinued. 

H. Stamm also measured the solubilities of the salts of the alkalies in liquid ammonia —potassium hydroxide, nitrate, sulphate, chromate, oxalate, perchlorate, persulphate, chloride, bromide, iodide, carbonate, and chlorate rubidium chloride, bromide, and sulphate esesium chloride, iodide, carbonate, and sulphate lithium chloride and sulphate sodium phosphate, phosphite, hypophosphite, fluoride, chloride, iodide, bromate, perchlorate, periodate, hyponitrire, nitrite, nitrate, azide, dithionate, chromate, carbonate, oxalate, benzoate, phtnalate, isophthalate ammonium, chloride, chlorate, bromide, iodide, perchlorate, sulphate, sulphite, chromate, molybdate, nitrate, dithionate, thiosulphate, persulphate, thiocyanate, phosphate, phosphite, hypophosphite, arsenate, arsenite, amidosulphonate, ferrocyanide, carbonate, benzoate, methionate, phenylacetate, picrate, salicylate, phenylpropionate, benzoldisulphonate, benzolsulphonate, phthalate, trimesmate, mellitate, aliphatic dicarboxylates, tartrate, fumarate, and maleinate and phenol. 

Kirch and Lehn have studied selective alkali metal transport through a liquid membrane using [2.2.2], [3.2.2], [3.3.3], and [2.2.C8] (146, 150). Various cryptated alkali metal picrates were transported from an in to an out aqueous phase through a bulk liquid chloroform membrane. While carrier cation pairs which form very stable complexes display efficient extraction of the salt into the organic phase, the relative rates of cation transport were not proportional to extraction efficiency and complex stability (in contrast to antibiotic-mediated transport across a bulk liquid membrane). Thus it is [2.2.Ca] which functions as a specific potassium ion carrier, while [2.2.2] is a specific potassium ion receptor (Table VI). 

Results presented below (in detail for potassium picrate) show that the phase boundary potential 0mx is constant over a range of concentrations of the salt. Deviation at the lower concentration end of this range is probably due to interference by other ions, while at the higher concentration end it is probably caused by change of the factor This factor is unlikely to approach constancy... 

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