Alkaline Earth Perchlorates

No attempt should be made to purify perchlorates, except for ammonium, alkali metal and alkaline earth salts which, in water or aqueous alcoholic solutions are insensitive to heat or shock. Note that perchlorates react relatively slowly in aqueous organic solvents, but as the water is removed there is an increased possibility of an explosion. Perchlorates, often used in non-aqueous solvents, are explosive in the presence of even small amounts of organic compounds when heated. Hence stringent care should be taken when purifying perchlorates, and direct flame and infrared lamps should be avoided. Tetra-alkylammonium perchlorates should be dried below 50° under vacuum (and protection). Only very small amounts of such materials should be prepared, and stored, at any one time. 

Ammonium, and Alkaline Earth Perchlorates in J.C. Schumacher Perchlorates, their Properties, Manufacture, and Uses , ACS Monograph 146, Reinhold, NY (1960), 30 6) L.W. Fagg,... 

The intensity of a flare is largely determined by its temp, which in turn depends on the stability of the reaction products. In order to generate grey body radiation which encompasses the spectral sensitivity of the human eye (0.4— 0.74pm), 3000°K should be exceeded. Whereas this is possible using nitrates and perchlorates with alkaline earth metals as well as Zr, Ti and Hf (Ref 34) (H, C, B, Si and P form oxides which dissociate at high temps), in practice Mg and A1 are found to be best in terms of heat output, cost, and transparency to visible radiation... 

The quantity dyl3 In a2 at the potential of the electrocapillary maximum is of basic importance. As the surface charge of the electrode is here equal to zero, the electrostatic effect of the electrode on the ions ceases. Thus, if no specific ion adsorption occurs, this differential quotient is equal to zero and no surface excess of ions is formed at the electrode. This is especially true for ions of the alkali metals and alkaline earths and, of the anions, fluoride at low concentrations and hydroxide. Sulphate, nitrate and perchlorate ions are very weakly surface active. The remaining ions decrease the surface tension at the maximum on the electrocapillary curve to a greater or lesser degree. 

Existing knowledge on perchloric acid and its salts was reviewed extensively in 1960 in a monograph including the chapters Perchloric Acid Alkali Metal, Ammonium and Alkaline Earth Perchlorates Miscellaneous Perchlorates Manufacture of Perchloric Acid and Perchlorates Analytical Chemistry of Perchlorates Perchlorates in Explosives and Propellants Miscellaneous Uses of Perchlorates Safety Considerations in Handling Perchlorates [1], There is a shorter earlier review, with a detailed treatment of the potentially catastrophic acetic anhydride-acetic acid-perchloric acid system. The violently explosive properties of methyl, ethyl and lower alkyl perchlorate esters, and the likelihood of their formation in alcohol-perchloric acid systems, are stressed. The instability of diazonium perchlorates, some when damp, is discussed [2],... 

Alkali, alkaline-earth, and rare-earth metal cations also catalyze electron transfer reactions. Thus, in the pair of Co -tetraphenylporphyrin complex with BQ, no redox reaction takes place, or it takes place too slowly to be determined. The metal cations promote this reaction. For example, in the presence of 80(0104)3, the corresponding rate constant of 2.7 X 10 M s was observed. BQ transforms into benzosemiquinone under these conditions (Fukuzumi and Ohkubo 2000). Zinc perchlorate accelerates the reaction between aromatic amines and quinones (Strizhakova et al. 1985). This reaction results in the formation of charge-transfer complexes [ArNHj Q ]. The complexes dissociate in polar solvents, giving ion-radicals ... 

The perchlorates oi the alkaline earths.—G. S. Serullas16 prepared deliquescent prisms of calcium perchlorate in 1831. The alcoholic soln. burnt with a red flame strontium perchlorate, with a purple flame. G. S. Serullas made trihydrated... 

The following Refs give some of the more important studies made with DTA apparatus Refs 1) S. Gordon C. Campbell, "Differential Thermal Analysis of Inorganic Compounds. Nitrates and perchlorates of the Alkali and Alkaline Earth Groups and their Subgroups1, AnalChem 27, 1102-09(1955) (Based on PATR 2079 (Nov 1954) PATR 2200(July 1955)1 2) S. Gordon C. Campbell "Pre-... 

Alkaline earth metal salts, such as the perchlorates, are also complexed by TMSB,189 and isolated species such as bis(2-amino-2-hydroxymethyl-l,3-propanediolato(l - )0,N)-copper(II)-sodium perchlorate H2O20° have also been found.30... 

For solutions containing sulphuric acid or a sulphate the reagent commonly applied is barium chloride, both when the test is to be qualitative and when quantitative. Precipitation is effected by the gradual addition of barium chloride to the boiling solution containing a little hydrochloric acid, but for the production of pure barium sulphate, and therefore in order to ensure accuracy, certain precautions must be observed.4 Nitrates, perchlorates, phosphates, tervalent metals and large quantities of salts of the alkali metals (particularly potassium) and of the alkaline earth metals are to be avoided, as they cause the precipitated barium sulphate to be rendered impure by occlusion of otherwise soluble substances.5 Such impurities may be accounted for partly by... 

Alkaline-Earth Perchlorates. Anhydrous alkaline-eartli metal perchlorates can be prepared by heating ammonium perchlorate in the presence of the corresponding oxides or carbonates. The alkaline-earth perchlorates are unusually soluble in organic solvents. 

Alkaline earth metalloporphyrins, M(Por), are obtained by porphyrin metallation with meta perchlorates in pyridine or metal hydroxides in methanol.175 They dissociate under mild conditions even in acetic acid. 

Tarnovskl Explosives. Blasting expls patented in Fr in 1913 (FrP 465082) and claimed to be more powerful than some NG Dynamites. A typical formulation consisted of Amm perchlorate 67, TNB 13, A1 powder 10 and wood-meal 10%. As these expls developed HC1 gas, they could be used only in open blasting operations. If, however, part of the perchlorate was replaced by alkali or alkaline earth nitrates, the expls would be suitable for use in mines Ref Colver (1938), 739... 

Perchlorates appear to fall into two broad categories those more4 or less5 sensitive to heat and shock. Included in the group of those qualitatively less sensitive are pure ammonium perchlorate, the alkali metal perchlorates, the alkaline earth perchlorates, and perchloryl fluoride. Among the more sensitive compounds are the pure inorganic nitrogenous... 

However, adds Schumacher, the more common ammonium, alkali metal, and alkaline earth perchlorates are considerably less hazardous. ... 

On the other hand, all of the alkaline earth metal salts brought about larger hypsochromic shifts than the alkali metal salts. A system magnesium perchlorate/ triethylamine and 4 (n = 1) shows the largest hypsochromic shift in all the systems examined. 

The fuels are, for example, 5-aminotetrazole, azodicarbonamide, -> Guanidine nitrate, -> Nitroguanidine, dicyandiamide, -> Triamino-guanidine nitrate and similar compounds, as well as salts of, for example, 5-nitrobarbituric acid, urea derivatives and also nitra-mines and similar compounds. The oxidisers are, for example, alkali or alkaline earth nitrates, -> Ammonium, alkali or alkaline earth perchlorates and metal oxides. 

The influence of the non-complex negative ion on the stability also becomes manifest in the anhydrous crystallization, for example, of the alkaline earth fluorides, but on the other hand sodium perchlorate is NaC104.H20 while the sulphate with the double-charged anion contains ioH20 (Glauber s salt). Here other factors play a part, since the perchlorate in question is hygroscopic and is also very readily soluble. 

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