Alkali metal perchlorates

Alkali Metal Perchlorates. The anhydrous salts of the Group 1 (lA) or alkah metal perchlorates are isomorphous with one another as well as with ammonium perchlorate. Crystal stmctures have been determined by optical and x-ray methods (38). With the exception of lithium perchlorate, the compounds all exhibit dimorphism when undergoing transitions from rhombic to cubic forms at characteristic temperatures (33,34). Potassium perchlorate [7778-74-7] KCIO, the first such compound discovered, is used in pyrotechnics (qv) and has the highest percentage of oxygen (60.1%). 

Perchlorates are known for most metals in the periodic table.The alkali-metal perchlorates are thermally stable to several hundred degrees above room temperature but NH4CIO4 deflagrates with a yellow flame when heated to 200° ... 

The Hg/dimethyl formamide (DMF) interface has been studied by capacitance measurements10,120,294,301,310 in the presence of various tetraalkylammonium and alkali metal perchlorates in the range of temperatures -15 to 40°C. The specific adsorption of (C2H5)4NC104 was found to be negligible.108,109 The properties of the inner layer were analyzed on the basis of a three-state model. The temperature coefficient of the inner-layer potential drop has been found to be negative at Easo, with a minimum at -5.5 fiC cm-2. Thus the entropy of formation of the interface has a maximum at this charge. These data cannot be described... 

Alkali-immobile dye-releasing quinone compounds, 19 293-294 Alkali lignins, 15 19-20 Alkali manganate(VI) salts, 15 596 Alkali manganates(V), 15 592 Alkali-metal alkoxide catalysts, 10 491 Alkali-metal alkoxides, effects of, 14 252 Alkali-metal alkylstannonates, 24 824 Alkali-metal fluoroxenates, 17 329-330 Alkali-metal hydrides, 13 608 Alkali-metal hydroxides, carbonyl sulfide reaction with, 23 622 Alkali-metal metatungstates, 25 383 Alkali-metal perchlorates, 18 211 Alkali-metal peroxides, 16 393... 

CA 60, 9044(1964) (Exothermic reaction mixtures for underwater propulsion and ignition devices contg alkali metal perchlorates and powdered Al, Be or Mg are improved in regard to their burning rates and pressure stability by incorporating ca, 1% of finely divided Fe) Ad 119) Dy-namit-Nobel AG, BelgP 627561(1963) ... 

Alkali Metal Perchlorates. The anhydrous salts of the Group 1 (IA) or alkali metal perchlorates are isomorphous with one another... 

The alkali metal perchlorates are either white or colorless, and have increasing solubility in water in the order of Na > Li > NH4 > K > Rb > Cs. The high solubility of sodium perchlorate. NaCI04. makes this material useful. 

Group 73 (IIIA) Perchlorates. Perchlorate compounds of boron and aluminum are known. Boron perchlorates occur as double salts with alkali metal perchlorates. Aluminum perchlorate, (CAS 14452-95-3J. Ai(C104)3. forms a series of hydrates. 

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... 

The decomposition of this salt has been the subject of several studies49-50 that agree on the major features. In contrast to the other alkali metal perchlorates, LiC104 is stable in the solid state and in the liquid up to approximately 390°C. The overall reaction is... 

Ammonium perchlorate is the most important oxygen carrier for -+ Composite Propellants. Unlike alkali metal perchlorates, it has the... 

Vibrations of the crystal components may destabilise a lattice structure above a particular temperature, but this does not necessarily result in melting if an alternative phase is stable. Normally the form stable at the higher temperature, generated by a reversible recrystallisation, is less ordered. An example is the orthorhombic to cubic transformation of the alkali metal perchlorates [7] which is associated with increased rotational freedom of the perchlorate anion. Studies of phase transformations are of value in advancing understanding of solid state decompositions. 

Transfer within ionic structure permanganates, alkali metal perchlorates. 

The influence of alkali metal perchlorates on the photocyclisation of (34) has also been studied. The quantum yield for cyclization is reduced from 0.21 for the free system to 0.17 for irradiations in the presence of sodium perchlorate. The effect is even more dramatic with potassium and rubidium perchlorates when (j) is reduced to 0.02. The crown ether systems are obviously important since the overall shape can be controlled by the photochemical ring closure. 

LiC104 is much more soluble in water than the other alkali metal perchlorates Mg(C104)2 and the later group 2 metal perchlorates are very soluble. 

Measurements on alkali metal perchlorates suggest that these salts are all detectably associated, the association constants decreasing in the sequence Li < Na < K Rb (the agreement with conductivity results ... 

Appendix 2.11.1 lists both the lattice free energies and enthalpies for a series of salts. All data are based on the standard state of 1 atm and 25°C and were calculated from eqns. 2.11.6 with the exceptions of the tetraalkylammonium halides and the alkali metal perchlorates which were calculated by statistical mechanics (eqns. 2.11.7, 2.11.8). 

In systems where only water molecules are coordinated to the metal ion (but not the organic component), the cause of the higher complex stability is the lower stability of the aquo complex, which is due to the reduced water activity resulting from dilution by the organic solvent [Be 70]. A similar effect may be achieved if the water activity of an aqueous solution is diminished by the dissolution of an inert salt, as shown by the complex stability measurements of Burger et al, [Bu 68] in concentrated alkali metal perchlorate solutions. 

Tetrahydrofuran (THF, Aldrich) was flask-to-flask distilled from the vacuum line immediately prior to use. Dichloromethane (Aldrich) was distilled from CaH2. All solutions were prepared either under vacuum or under an atmosphere of dry N2. Tetrabutylanunonium perchlorate (TRAP, Fluka) was twice recrystallized from EtOAc and stored in a desiccator. Alkali metal perchlorate salts (Aldrich) were recrystallized from deionized water and dried in a vacuum oven at 100°C for 24 h. 

Perchloric acid is an extremely strong acid in aqueous solution (see Table 7.3). Although [ 104] (Fig. 17.12b) does form complexes with metal cations, the tendency to do so is less than for other common anions. Consequently, NaC104 solution is a standard medium for the investigation of ionic equilibria in aqueous systems, e.g. it is used as a supporting electrolyte in electrochemical experiments (see Box 8.2). Alkali metal perchlorates can be obtained by disproportionation of chlorates (eq. 17.76) under carefully controlled conditions traces of impurities can catalyse decomposition to chloride and O2. Perchlorate salts are potentially explosive and must be handled with particular care. For example, solid NH4CIO4 decomposes at 298 K according to eq. 17.79, and mixtures of ammonium perchlorate and aluminium are standard missile propellants. 

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