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As a part of a broad programme of investigation of sodium hydroxide, the transitions up to its melting point were studied. This was accomplished by correlation of results obtained through use of differential thermal, high-temperature microscopic, and high-temperature X-ray analyses. The melting of sodium hydroxide monohydrate, the driving off of entrapped water at higher temperatures, the transition of x-sodium hydroxide to β-sodium hydroxide, and the melting point of β-sodium hydroxide were the transitions identified and studied. An X-ray powder pattern for β-sodium hydroxide was obtained; it appeared to indicate a cubic structure for this material, with a lattice parameter of 11.0 A.

The crystal structures of the isomorphous garnet‐red copper salts, KCuCl3 and NH4CuCl3, have been determined. Each compound contains discrete, planar, Cu2Cl6= dimers. These dimers are stacked above each other along the crystallographic a axis. The cation exhibits a ninefold coordination.KCuCl3 is antiferromagnetic below 30°K. Both KCuCl3 and NH4CuCl3 are pleochroic with maximum visible absorption when the electric vector is parallel with the Cu–Cu vector of the dimer.

Radial distribution functions were calculated for 19 concentrated solutions of eight alkali‐metal halides. These are analyzed in terms of the sizes and environments of the aqueous ions. The sizes of the hydrated and associated ions are found to be given by their respective crystal ionic radii. From seven to nine water molecules occupy the first hydration spheres of non‐associated halide ions, the numbers being relatively independent of solution concentration but increasing slightly with increasing size of the ion. Second and third hydration spheres are correlated with the halide ions, the region of influence for the anions being larger than for the cations studied. Positive ions are found to lie on the dipolar axes and negative ions on the hydrogen—oxygen bond axes of the primary waters of hydration. In contrast to the lithium and sodium halide solutions, considerable direct contact among ions exists in cesium halide solutions. Increasing association occurs with increasing concentration of the solutions and decreasing size of the halide ion. No preferred spatial arrangement is found for the associated ionic species.

Co 2 chloride aqueous and alcoholic solutions by X ray diffraction to find potential ligands relative coordinating abilities

The structures of arsenic sulfide glass, two synthetic glasses, PbS·5As2S3 and 2PbS·5As2S3, and a natural glass, 5PbS·3As2S3, have been studied by x‐ray diffraction. Arsenic is found to have three sulfur neighbors in the first three glasses, just as in crystalline arsenic sulfide. The natural glass and crystalline lead sulfide are similar in that lead is situated in octahedral holes among closely packed sulfurs. The increased ratio of sulfur to arsenic in the natural glass results in four sulfur neighbors for each arsenic. The lead‐sulfur distance is about 3.1 A, and that for arsenic‐sulfur is about 2.3 A.

The structure of the solute species in concentrated iron(III) chloride–methanol solutions has been examined by diffraction techniques. Solute association is established by colligative measurements and indirectly by diffraction results and Fe2Cl6 emerges as a realistic solute species. The radial‐distribution functions of the solutions and those obtained from electron diffraction studies of vapor‐phase Fe2Cl6 are comparable. The average iron(III)–chloride bond distance is 2.25 A, and each iron atom has four chloride nearest neighbors; both facts are consistent with the dimer model. Crystal radii serve to interpret bond distances.

X‐ray studies of solutions of zinc bromide show four coordination for the zinc ion. In concentrated water and acetone solution, zinc is coordinated by two bromines and two oxygens, on the average. If the bromine/water ratio is increased by adding hydrobromic acid, zinc becomes totally coordinated by halide. These solutions are too concentrated, however, to speak of the existence of discrete ZnBr4= ions. Crystal radii serve to interpret contacts between species in solution.

The intensity functions, distribution functions, and the fit of the first maxima with a sum of calculated contributions are graphically presented. The liquids had mole fractions of 1.0, 0.9, 0.7, 0.5, 0.3, and 0.0 in mercury. The temperatures were 23, 24, 24, 24, 140, and 175 deg C; and the densities tively. The first maximum in each of the distribution functions is practically symmetrical and can be accounted for by assuming the same pair distribution exists over the entire composition range. (N.W.R.)

X‐ray diffraction measurements show that in liquid ammonia each molecule is surrounded on the average by about 11 other molecules. There is evidence that hydrogen‐bonded approaches occur at a mean distance of 3.56 A, and that the short‐range spectrum of intermolecular distances resembles that of crystalline ammonia. These results are used to interpret the volume changes occurring upon dissolution of alkali metals in liquid ammonia.