Perchlorate ions

Within each group relatively simple molecules will be discussed first. In some cases a given substrate may be reduced by modes (i) and (ii) depending on the reductant and in other cases the mechanism is unknown, for example the reduction of perchlorate ion may involve either electron-acceptance or oxygen atom transfer. 

This ion, thermodynamically a powerful oxidant , is reduced by comparatively few reagents. However, both V(II) and V(III) are effective , viz. 

Ti(III) also reduces aqueous acidic CIO4. in accordance with the stoichiometry given for V(ir) and with kinetics 

Reduction by Ru(NH3) is simple second-order and acid-independent . k2 is 2.5 X 10 l.mole . sec at 25 °C n = 0.142 M). Reduction by the corresponding hexammine is about 100 times slower. 

Reduction by Eu(II) in a perchlorate medium is too fast for conventional study but chloride ion retards the reaction.  

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The perchlorate ion, CIO , is considered to be noncoordinating ia the presence of water. When water is rigorously excluded, anhydrous complexes such as Ni(CH2CN) (C10 2> where n is 2, 4, or 6, can be prepared. Perchlorate complexes of Ni, Co, Cu, and Sn have been reported. In each case, however, an organic group such as CH CN, CH, or pyridyl is involved (73—76). 

Tetraphenylarsonium chloride (107,108) has also been used for the precipitation of the perchlorate ion in gravimetric analysis. 

Perchlorate ion established as a monodentate ligand (to Co) by X-ray crystallography, following earlier spectrosopic and conductimetric indications of coordination (1961)... 

On the other hand, in the single crystals prepared from equivalent amounts of heterochiral 1 1 complexes, a pair of two heterochiral 1 1 complexes are incorporated in a unit cell to form a layered structure with alternate layer distances of 7.33 and 7.6 A. Two perchlorate ions stay in the narrower gap, and two additional acetone molecules as crystallization solvent occupy the wider gap. The perchlorate ions interact with two axial water ligands by hydrogen bonds (3.71 and 3.77 A) to construct a layered structure. The adjacent two molecules of heterochiral 1 1 com-... 

Freiman, L. I. and Kolotyrkin, Ya. M., Pitting Corrosion of Iron by Perchlorate Ions , Dokl. 

Large amounts of chloride, cobalt(II), and chromium(III) do not interfere iron(III), nickel, molybdenum)VI), tungsten(VI), and uranium(VI) are innocuous nitrate, sulphate, and perchlorate ions are harmless. Large quantities of magnesium, cadmium, and aluminium yield precipitates which may co-precipitate manganese and should therefore be absent. Vanadium causes difficulties only... 

Since the early days of using PVC separators in stationary batteries, there has been a discussion about the generation of harmful substances caused by elevated temperatures or other catalytic influences, a release of chloride ions could occur which, oxidized to perchlorate ions, form soluble lead salts resulting in enhanced positive grid corrosion. Since this effect proceeds by self-acceleration, the surrounding conditions such as temperature and the proneness of alloys to corrosion as well as the quality of the PVC have to be taken carefully into account. 

It was found that chlorides, chlorates, and nitrates interfere by forming in sol ppts (Ref 6). Later it was found that w sol perchlorates could be analyzed gravimetrically by pptn of the perchlorate ion as tetraphenylarsonium perchlorate (Ksp at 20° = 2.60 0.14 x 10"9). The ppt can be (Tried at 105° and weighed directly (Ref 16). Still more recently a specific perchlorate ion electrode has been developed (Ref 17) which can be used for the potentiometric titration of the perchlorate ion using a soln of tetraphenylarsonium chloride as the titrant (Ref 15). Tetra-phenylphosphonium chloride has been similarly used, but the corresponding Sb compd is too insol in w for practical use (Ref 8), For routine assay of perchlorates for use by the armed forces, a Na carbonate fusion procedure is described in Mil Specs MlL-A-23946 (19 Aug 1964) MIL-A-23948 (19 Aug 1964) (see also under Ammonium Perchlorate). The tetraphenylarsonium chloride procedure has also been proposed for use in Mil Specs (Ref 11)... 

Schmid (1936b, 1937) found that diazotizations in the presence of hydrochloric or hydrobromic acid were catalyzed by halide ions, whereas an analogous effect did not occur with hydrogen sulfate or perchlorate ions. 

Hisatsune and Linnehan [299] have used infrared measurements to study the decomposition of C104 in a KC1 matrix. Despite the differences in the environment of the perchlorate ion, the kinetics of reaction were similar to those reported by Cordes and Smith [845] for pure KC104. The reaction was second order and E was 185 kJ mole-1. Comparable behaviour was observed for CIOJ in KC1, except that E was lower ( 125 kJ mole-1) and when both ions (CIOJ and C104) were present the reaction was approximately first order. 

Addition of perchlorate ion had little kinetic effect, but addition of chloride ion decreased the rate and complicated the kinetics, probably through intervention of the equilibrium... 

Unionized mercuric acetate is also a mercurating species, for the second-order rate coefficient for mercuration of benzene by mercuric acetate in acetic acid at 25 °C is 0.41 x 10"7. If mercuration took place via ionized acetate ion pairs HgOAc+OAc" for which AT, the equilibrium constant can be estimated at 2 x 10"8, then since the rate of mercuration by this ion pair will be approximately the same as by the acetoxymercury perchlorate ion pair for which k2 the second-order rate coefficient has been determined (above) as 0.37x10"3 at 25 °C, the observed second-order rate should be 2 x 10"8 x0.37 x 10"3 = 0.74xl0-11. This is so different from the rate actually observed that mercuration by the ion pair can be eliminated which leaves ionized mercurcy acetate as the only possible mercurating species439. 

MacDonald on the adsorption of chloride ions in passivation, 237 of CO on electrochemically facetted platinum, 135 of diols on mercury, 188 of neutral compounds on electrodes, 185 of perchlorate ions, copper and, 94 specific adsorption, anodic dissolution and, 256... 

Radio tracer studies, and adsorption of perchlorate ions on copper, 94 Raman s scattering, and differential capacitance, 80... 

Some elements—particularly the halogens—form more than two kinds of oxoanions. The name of the oxoanion with the smallest number of oxygen atoms is formed by adding the prefix hypo- to the -ite form of the name, as in the hypochlorite ion, CIO-. The oxoanion with the most oxygen atoms is named with the prefix per- added to the -ate form of the name. An example is the perchlorate ion, C104-. The rules for naming polyatomic ions are summarized in Appendix 3A and common examples are listed in Table D.l. 

Write the Lewis structure, including typical contributions to the resonance structure (where appropriate, allow for the possibility of octet expansion, including double bonds in different positions), for (a) sulfite ion (b) hydrogen sulfite ion (c) perchlorate ion (d) nitrite ion. 

Compounds of septivalent chlorine probably contain chlorine with a polar valence of +3 and with four shared electron bonds. Thus the perchlorate ion would be formed from Cl +3 and 4 0 and would have... 

Lewis s theory and Heitler and London s extension permitted the reasonably certain attribution of specific electronic formulas to a great many compounds. In other cases, however, it was possible to set up a number of alternative electronic formulas for a molecule or crystal, and often no sound argument could be advanced supporting any one of them against the others. For example, Lewis gave the perchlorate ion the... 

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