Iodates properties

Chlorates and bromates feature the expected pyramidal ions X03 with angles close to the tetrahedral (106-107°). With iodates the interatomic angles at iodine are rather less (97-105°) and there are three short I-O distances (177-190 pm) and three somewhat longer distances (251-300 pm) leading to distorted perovskite structures (p. 963) with pseudo-sixfold coordination of iodine and piezoelectric properties (p. 58). In Sr(I03)2.H20 the coordination number of iodine rises to 7 and this increases still further to 8 (square antiprism) in Ce(I03)4 and Zr(I03)4. 

Mixtures of aluminium powder with liquid chlorine, dinitrogen tetraoxide or tetran-itromethane are detonable explosives, but not as powerful as aluminium-liquid oxygen mixtures, some of which exceed TNT in effect by a factor of 3 to 4 [1], Mixtures of the powdered metal and various bromates may explode on impact, heating or friction. Iodates and chlorates act similarly [2], Detonation properties of gelled slurries of aluminium powder in aqueous nitrate or perchlorate salt solutions have been studied [3], Reactions of aluminium powder with potassium chlorate or potassium perchlorate have been studied by thermal analysis [4],... 

Results obtained from the alkali iodides on the isomer shift, the NMR chemical shift and its pressure dependence, and dynamic quadrupole coupling are compared. These results are discussed in terms of shielding by the 5p electrons and of Lbwdins technique of symmetrical orthogonalization which takes into account the distortion of the free ion functions by overlap. The recoilless fractions for all the alkali iodides are approximately constant at 80°K. Recent results include hybridization effects inferred from the isomer shifts of the iodates and the periodates, magnetic and electric quadrupole hyperfine splittings, and results obtained from molecular iodine and other iodine compounds. The properties of the 57.6-k.e.v. transition of 1 and the 27.7-k.e.v. transition of 1 are compared. 

Studies of medium effects on hexacyanoferrate(II) reductions have included those of dioxygen,iodate, peroxodisulfate, - [Co(NH3)5(DMSO)] +, and [Co(en)2Br2]+. Rate constants for reaction with dioxygen depended strongly on the electron-donor properties of the organic cosolvent. Rate constants for reduction of peroxodisulfate in several binary aqueous media were analyzed into their ion association and subsequent electron transfer components. Rate constants for reduction of [Co(en)2Br2] in methanol water and dioxan water mixtures were analyzed by a variety of correlatory equations (dielectric constant Grunwald-Winstein Swain Kamlet-Taft). 

Am3+ is the most stable oxidation state of the metal. In trivalent state, its properties are simdar to europium. Am3+ reacts with soluble fluoride, hydroxide, phosphate, oxalate, iodate and sulfate of many metals forming precipitates of these anions e.g., Am(OH)3, Am(103)3, etc. 

Salts of very powerful oxidizing acids (eg chromic or permanganic) are unknown, and are unlikely to exist. Hydrazonium iodate may exist in solution at low temp (Ref 27a). Alkali metals, amides and hydrides react with hydrazine to give the corresponding alkali hydrazide. Sodium hydrazide explodes violently in the presence of 02 or when heated above 100°C—a typical behavior of the alkali hydrazides. For other reactions, see Ref 24 Explosive and Combustion Properties... 

From these measurements it appears that the stability of the compounds does not follow the expected order of chlorate < bromate < iodate. This behavior, however, cannot be regarded to be a characteristic property of ammonium halogenates only, because according to our experiments the same order of stability has been found in case of potassium halates. It is fairly difficult to propose a reliable reaction mechanism merely from kinetic data... 

Freshly acidified iodate plus iodide can be used to standardize thiosulfate. The I3 must be used immediately or else it is oxidized by air. The disadvantage of KI03 is its low molecular mass relative to the number of electrons it accepts. This property leads to a larger-than-desirable relative weighing error in preparing solutions. 

Property Radium Bromide Carbonate Chloride Hydroxide Iodate Nitrate Sulfate... 

The strontium analog of colemanite, 2SrO 3B203 5H20, can be prepared from the reaction between strontium iodate and borax in water at 65°C (436). Like colemanite, it possesses ferroelectric properties. 

In general, iodates are thermally rather stable. Many of them can be heated to several hundred °C without appreciable decomposition. When they do decompose, it is frequently in the solid state or on melting. Thus there are virtually no properties of liquid iodates known. The decomposition reactions fall into three groups ... 

During the early 1970s researchers at Bell Laboratories studied these salts, both hydrated and anhydrous, because of their interest in the electrical, magnetic, and structural properties of the compounds. Syntheses were also studied and the results were compared with previously published results.82 83 Densities of all the anhydrous rare-earth iodates, derived from crystallographic data,83a are listed in Table 9.20. Extensive crystallographic data of these salts are also provided, as is a comparison with previous work cited in our earlier publication.2... 

Note that in the solid state, some metal halates do not consist of discrete ions. For example, in the iodates there are three short 1-0 distances 177-90 pm and three longer distances 251-300 pm, leading to distorted pseudo-sixfold coordination and piezoelectric properties. 

In this section, the physical and chemical properties of oxidizers commonly found in metal CMP slurries, such as nitric acid, ferric salts, hydrogen peroxide, iodates, permanganates, and chromates, are first described. The focus will then turn to their capability in material removal rate and their corrosion tendency of the metal films of interest. 

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