Perchlorate anions

Crystals of uranyl perchlorate, U02(C10[13093-00-0] have been obtained with six and seven hydration water molecules. The uranyl ion is coordinated with five water molecules (4) in the equatorial plane with a U—O(aquo) distance of 245 nm (2.45 E). The perchlorate anion does not complex the uranyl center. The unit cells contain two [0104] and one or two molecules of hydration water held together by hydrogen bonding (164). 

For purposes of characterization of enamines the perchlorate salts are preferred, as they crystallize well, and the perchlorate anion has no tendency to add to the iminium cation. Other salts, including hexachlorostannates (13), hexachloroantimonates (13), chlorides, bromides, tetraphenylborates, and nitrates, have also been used. Recently a method for the preparation of iminium salts directly from aldehydes or ketones and the amine perchlorate has been reported (16). 

LP-DE has a weaker catalytic activity than BF3-Et20, AICI3 and TiCU because the Lewis acidity of the lithium cation is moderated by complex-ing with diethyl ether and perchlorate anion [37], but it becomes a highly oxophilic Lewis acid when concentrated solutions are used [38]. The concentration of LP-DE is therefore sometimes essential for the success of the reaction. 

An oxoacid that forms from a polyatomic anion whose name ends in -ate has a name ending in -ic. For example, HNO3 forms by adding a proton to the nitrate polyatomic anion, so HNO3 is nitric acid. Likewise, HCIO4 is perchloric acid from the perchlorate anion. 

In this contribution, we present new results of a cychc voltanunetiy study of the influence of (CeHglads on Hypo and on anion adsorption at the Pt(l 11) electrode in aqueous HCIO4 and H2SO4, and relate them to analogous studies at Pt(110) and Pt(lOO) electrodes in aqueous H2SO4. Perchlorate anions are known to be less strongly adsorbed on Pt than bisulfate or sulfate anions thus, the cychc voltanunetiy behavior in the two electrolytes is expected to reveal important differences. 

If the dielectric constant of an amphiprotic solvent is small, protolytic reactions are complicated by the formation of ion pairs. Acetic acid is often given as an example (denoted here as AcOH, with a relative dielectric constant of 6.2). In this solvent, a dissolved strong acid, perchloric acid, is completely dissociated but the ions produced partly form ion pairs, so that the concentration of solvated protons AcOH2+ and perchlorate anions is smaller than would correspond to a strong acid (their concentrations correspond to an acid with a pK A of about 4.85). A weak acid in acetic acid medium, for example HC1, is even less dissociated than would correspond to its dissociation constant in the absence of ion-pair formation. The equilibrium... 

The use of the perchlorate anion to precipitate the cobalt complex to determine the yield [1] is deprecated on the grounds of potential hazard [2], though it was not found possible to cause the salt to detonate by pounding, but it will bum if ignited. A spectroscopic assay method is suggested as an alternative to precipitation [3],... 

Fig. 7 Projection of the crystal structure of [Fe(btr)3](C104)2 on the (ab) plane. The hydrogen atoms and the perchlorate anions are omitted for clarity...

However, we cannot agree with their suggested reaction scheme. In particular, their penultimate equation in which a free proton appears to be released from an oligostyryl cation is implausible. It might be combined with their last equation, in which the free proton is shown reacting with perchlorate anion, but then the resulting reaction orders would be incompatible with observation. 

Table 71 shows the general tendency of a higher chiral recognition in complexes with hexafluorophosphate than with perchlorate anions. This might reflect the slightly higher stability of PF complexes. 

Unexpected uniformities observed in the impact-sensitivities of a group of 22 amminecobalt oxosalts are related to kinetic factors during the initiation process [6], A series of ammine derivatives of cadmium, cobalt, copper, mercury, nickel, platinum and zinc with (mainly) iodate anions was prepared and evaluated as explosives [7], Earlier, ammine and hydrazine derivatives of cadmium, cobalt, copper and nickel with chlorate or perchlorate anions had been evaluated as detonators. Dihydrazinecopper(II) chlorate had exploded when dried at ambient temperature [8],... 

Vidali, M. et al J. Inorg. Nucl. Chem., 1975, 37, 1715-1719 A series of uranyl complexes of macrocyclic azomethines were used as ligands for transition metal ions, with perchlorate anions. Raman spectra of the uranyl-metal complexes could not be recorded because the samples exploded during attempted measurements. 

Perchloric acid is often a good choice since the perchlorate anion can be assumed to be wholly nonexplosion risk if used in conjunction with organic materials. 

Electron distributions are studied in the perchlorate anion and in the radical in order to elucidate the pattern of bonding in these systems. Qualitative considerations are supplemented with numerical calculations. Comparison with other efforts supports the previously suggested interpretation of the radical as a weakly exchange coupled complex of an oxygen diatom and a chloryl radical. 

Interestingly, the acetoxyl group in the product comes not from acetic acid (a solvent) but from acetate ion (a conducting electrolyte)—salts with tosylate or perchlorate anions stop acetoxylation in the solution of acetic acid. 

---