Metal perchlorate transport

Technique for Measurement of Metal Perchlorate Transport Across Bulk Chloroform Membranes. 

According Pearson s Hard and Soft Acid and Base Theory, oxygen is a hard donor atom, sulfur is a soft donor atom and nitrogen is intermediate (14,15), To probe the influence of replacing one or two oxygen atoms in lipophilic crown ethers 5, 6 and 8 upon metal perchlorate transport, the lipophilic macrocyclic carriers 9-16 (Figure 3) were investigated. Macrocycles 9 and 10 are lipophilic diaza-15-crown-5 compounds and 11,14 and 15 are diaza-18-crown-6 derivatives. Macrocyle 16 is a lipophilic monothia-15-crown-5 compound and macrocycles 12 and 13 are dithia-15-crown-5 and -18-crown-6 compounds, respectively. 

Comparison of the data for the lipophilic diazacrown ethers in Table 2 with that for the analogous crown ether compounds in Table 1 shows that replacement of two oxygen atoms in the macrocyclic ring with NH or NC2H5 units drastically reduces the alkali metal perchlorate transport. Presumably this results from diminished complexation of the hard alkali metal cations by the macrocyclic ligands when two hard oxygen donor sites are replaced by two nitrogen atoms. 

We have developed efficient syntheses of. /w-(hy(iroxy)dibenzo-16-crown-5 and jyw-(alkyl)(hydroxy)dibenzo-16-crown-5 compounds 17,18). These lariat ether alcohols, in which the alcohol function and a hydrogen atom or alkyl group are attached to the central carbon of the three-carbon bridge serve as platforms for attachment of various potential coordinating groups to provide a variety of other lariat ether compounds. For example, dibenzo-16-crown-5 lariat ethers with pendent amide 19), ester 20) and thioamide (27) groups have been prepared. To further probe the effect of structural variation within lariat ethers, studies of metal perchlorate transport across bulk chloroform membranes by dibenzo-16-crown-5 lariat ethers with oxyacetamide and oxythioacetamide side arms were undertaken. 

Alkali metal perchlorate transport lariat ether amides, 161-164 lipophilic 18-crown-6 and 15-crown-5 derivatives, 157-160... 

Transport Conditions Source phase Metal perchlorate(0.50 mmol)/ H 0(5 ml). Membrane Carrier (0.0372 mmol)/CHClo(12 ml). Receiving phase H 0(5 ml). 

Transport Conditions Source phase Metal perchlorate(0.50 mmol)/ ... 

Transport of Alkali Metal Perchlorates by Lipophilic 18-Crown-6 and 15-Crown-5 Derivatives. 

Transport rates of the five individual alkali metal perchlorate species across bulk chloroform membranes by dicyclohexano-18-crown-6 (2) and lipophilic crown ethers 3-8 are recorded in Table 1. In all cases, transport of lithium perchlorate was undetectable. The K /Na and K /Rb transport selectivities calculated from the single species transport rates are also presented in Table 1. 

The transport of alkali metal perchlorates across the bulk chloroform membrane by dicyclohexano-18-crown-6 (2) varies with the nature of the alkali metal cation in the order K >Na >Rb >Cs >Lr. For the 18-crown-6 ring size, strongest complexation of would be anticipated and the transport shows modest K /Na and K /Rb selectivities. For the transport of alkali metal nitrates across a bulk chloroform membrane by 2, an ordering of K >Rb >Na >Cs >Lr has been reported (77). This reversal in the ordering for transport of Na and Rb is attributed to an effect of the co-transported anion upon transport selectivity (75). 

Transport by Metal Perchlorates by Lipophilic Diaza-, Monothia- and Dithia-15-crown-5 and -18-Crown-6 Compounds. 

Transport rates for alkali metal perchlorates across bulk chloroform membranes by the lipophilic diazacrown compounds 9-11,14 and 15 are presented in Table 2. In all cases, transport of lithium and cesium perchlorates was undetectable. 

Transport experiments were also conducted with metal perchlorates for which the metal ions were softer (Ag", Cd ", Co ", Hg ", Pb and Zn ). For none of these metal perchlorates was transport detectable. 

Transport of Metal Perchlorates by Lariat Ethers Based on Dibenzo-16-crown-5 Compounds with Amide- and Thioamide-Containing Side Arms. 

Amide-containing dibenzo-16-crown-5 compounds, transport of metal perchlorates, 161-165 Amine(s) as carriers, carbon dioxide facilitated transport through functional membranes prepared by plasma graft polymerization, 252-268 Amine solutions, carbon dioxide facilitated transport through supported liquid membranes, 239-250 Amino acid derivatives, use as heavy metal ion carriers, 175-179... 

Group 3 Nitrate/metal compositions without sulphur Compositions with <35-65% chlorate Compositions with black powder Lead oxide/silicon with >60% lead oxides Perchlorate/metal Burn fast Large firework shells Fuse protected signal flares Pressed report cartridges in primary packagings Quickmatches in transport packagings Waterfalls Silver wheels Volcanoes Black powder delays Burn very violently with single-item explosions... 

The effect of fluoride ions on the electrochemical behaviour of a metal zirconium electrode was studied by Pihlar and Cencic in order to develop a sensor for the determination of zirconium ion. Because elemental zirconium is always covered by an oxide layer, the anodic characteristics of a Zr/Zr02 electrode are closely related to the composition of the electrolyte in contact with it. These authors found the fluoride concentration and anodic current density to be proportional in hydrochloric and perchloric acid solutions only. In other electrolytes, the fluoride ion-induced dissolution of elemental zirconium led to an increase in the ZrOj film thickness and hindered mass transport of fluoride through the oxide layer as a result. The... 

The operation in kneaders or disk mixers begins with the mixing of all the ingredients, except those which sensitize the mixture to impact and friction, e.g. potassium or ammonium perchlorates. Molten TNT or another nitro compound (DNT) is then poured in, the whole is carefully stirred and cooled while stirring. Only when the temperature has fallen to 40-50°C, are the perchlorates added. When the material is cooled down to a temperature of 25-30°C, it is stirred for a certain time, then unloaded and transported in sheet metal or wooden boxes to the storeroom. 

Compositions with black powder Lead oxide/silicon with >60% lead oxides Perchlorate/metal compositions other than report Quickmatches in transport packagings Waterfalls Silver wheels Volcanoes Black powder delays ... 

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