Binary iodides

Annealing of stoichiometric amounts of the binary iodides or, alternatively, a one-batch synthesis from AI, R, and I2 yields satisfyingly pure ternary rare-earth iodides. 

Halides. AH of the anhydrous and hydrated binary haUdes of iron(Il) and iron(Ill) are known with the exception of the hydrated iodide of iron(Ill). A large number of complex iron haUdes have been prepared and characterized (6). 

Binary Compounds. The mthenium fluorides are RuF [51621 -05-7] RuF [71500-16-8] tetrameric (RuF ) [14521 -18-7] (15), and RuF [13693-087-8]. The chlorides of mthenium are RUCI2 [13465-51-5] an insoluble RuCl [10049-08-8] which exists in an a- and p-form, mthenium trichloride ttihydrate [13815-94-6], RuCl3-3H2 0, and RuCl [13465-52-6]. Commercial RuCl3-3H2 0 has a variable composition, consisting of a mixture of chloro, 0x0, hydroxo, and often nitrosyl complexes. The overall mthenium oxidation state is closer to +4 than +3. It is a water-soluble source of mthenium, and is used widely as a starting material. Ruthenium forms bromides, RuBr2 [59201-36-4] and RuBr [14014-88-1], and an iodide, Rul [13896-65-6]. 

Almost all of the rare-earth metal/rare-earth metal tri-iodide systems, R/RI3, contain binary phases with the rare-earth element in an oxidation state lower than -1-3 ( reduced rare-earth metal iodides) [3, 7, 10-13]. More common is the oxidation state -i-2. Elements that form di-iodides RI2 are illustrated in Fig. 4.1. 

Halogens, the elements in Group 17 of the periodic table, have the largest electron affinities of all the elements, so halogen atoms (a n readily accept electrons to produce halide anions (a a. This allows halogens to react with many metals to form binary compounds, called halides, which contain metal cations and halide anions. Examples include NaCl (chloride anion), Cap2 (fluoride anion), AgBr (bromide anion), and KI (iodide anion). 

In the second part of the paper 6.10 [143] this writer generalises his new kinetic treatment of living polymerisations [134], By applying it to data from the literature, he shows how this treatment can reveal which one of the components of a binary syncatalytic system (e.g. I2 and organic iodide) determines the concentration of the propagating species and, much more important, how the rate-constant of propagation can be calculated from readily available data. There remains here a rich mine of information to be exploited by others. 

Binary Compounds. The thermodynamics of the formation of HfCl2, of HfCl4, fused sodium and potassium chlorides have been described. The reduction of ZrXj (X = Cl, Br, or I) with metallic Zr or A1 in molten AICI3 has been studied at temperatures from 250 to 360 °C, depending on the halide. The electronic spectra of the initial reaction products were consistent with either a solvated Zr complex or an intervalence Zr "-Zr" species. Further reduction resulted in the precipitation of reduction products which were identified by analysis and i.r., electronic, and X-ray powder diffraction spectra. The stability of the trihalides with respect to disproportionation was observed to increase from chloride to iodide thus ZrC and ZrCl2,0.4AlCl3 were precipitated, whereas only Zrlj was formed. ... 

Studies of medium effects on hexacyanoferrate(III) oxidations have included those of iodide and of sulfite,in aqueous salt solutions as well as in binary aqueous solvents. 

The typical V-curve for eutectic mixtures is obtained with mixtures of potassium chloride with 39 per cent, of potassium fluoride at 605° 76 of potassium bromide at 740° 69 3 of potassium iodide at 580° and 42 8 of potassium sulphate at 705°. Results with binary mixtures of the alkali chlorides are indicated in the accompanying Table XVIII, where the eutectic temp, is bracketed with the atomic percentage of the element indicated on the same horizontal line S means that an unbroken series of solid soln. are formed otherwise, solid soln. are wanting. 

The ruthenium source was typically Ru02, RuCl3, Ru(acac)3, [Ru4(H)4(CO)i2] or a binary carbonyl, again with a source of iodide present as a promoter 384,385 Mel, EtI or HI was employed. Both complex (90) and [Ru2I2(CO)6] were observed in the reaction mixtures. The reaction gave carboxylic acids of longer chain length than propionic acid. A mechanism was proposed in which the precise nature of the iodocarbonyl complexes was not specified (Scheme 21). 

E. Peligot said that after being melted, the peroxide requires a much lower temp, for its solidification, for at —16° the compound remains liquid, and J. Fritzsche said that it can be re-solidified only at —30° because a little nitric acid has been formed, and this also accounts for the turbidity of the cooling liquid. For the fusion curve with nitric oxide, vide supra, nitrogen trioxide. P. Pascal studied the f.p. of binary systems of nitrogen peroxide with bromoform, chloroform, carbon tetrachloride, bromobenzene, methyl iodide, chloropicrin, and camphor. 

The kinetics of the reaction between bromopropionate and thiosulfate ions have been studied at 10-40 °C in various ethanol-water mixtures.107 Activation parameters were evaluated as a function of ionic strength and dielectric constant of the medium. The medium effect of mixed solvents on the rate constants of the Menshutkin reaction of triethylamine with ethyl iodide has been studied for binary mixtures of cyclohexane with benzene or ethyl acetate,108 and with chlorobenzene or dimethoxyethane.109 Rates were measured over the temperature range 293.1-353.1 K, and activation parameters were determined. 

Elemental chlorine, bromine and iodine are much more convenient reagents than fluorine for the preparation of compounds containing E-X bonds. Binary chlorides, bromides and iodides are often best made by direct interaction of the elemental substances. 

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