Showing papers by "Hitoshi Ohtaki published in 1975"

Ionic Equilibria in Mixed Solvents. XI. A Critical Survey of Hydroxo Complexes of Beryllium in Aqueous and Aqueous Mixed Solvents

Abstract: Hydrolytic reactions of beryllium ion were studied in water-methanol, water-ethanol, and water-acetone mixtures, 0.2 mole fraction of an organic component being contained. In all the solutions containing 3M LiClO4 as an ionic medium at 25 °C, we found the Be2OH3+, Be2(OH)22+, Be3(OH)33+, and Be(OH)2 complexes. However, in a supplementary work in a 3M LiClO4 aqueous medium in which the solution had been equilibrated with precipitates of beryllium hydroxide and the supernatant was subjected to titration, we found Be6(OH)84+ instead of Be(OH)2. From a very slow equilibrium observed in the high pH region, we concluded that the Be(OH)2 complex formed by the addition of an alkaline solution gradually polymerizes to Be6(OH)84+ by releasing some OH− ions. Through these observations a critical survey is described for the species reported by various authors. The solvent effect on the formation constants of hydroxo complexes is also discussed.

An X-Ray Diffraction Study of the Structures of the Hexachloro-and Hexabromoplatinate(IV) Ions in Aqueous Solution

Abstract: The structures of the PtCl62− and PtBr62− complexes in aqueous solution were determined by means of X-ray diffraction measurements of concentrated solutions of hexachloro- and hexabromoplatinic acids. Analysis of X-ray scattering data showed that the PtCl62− and PtBr62− complexes have a regular octahedral symmetry. The interatomic distances within the complexes are: Pt–Cl, 2.33 A; cis-Cl–Cl, 3.30 A; trans-Cl–Cl, 4.66 A; Pt–Br, 2.47 A; cis-Br–Br, 3.50 A; trans-Bv–Br, 4.94 A. These distances are in good agreement with those reported in crystals of hexahalogenoplatinate(IV) compounds.

Ionic equilibria in mixed solvents part 11, a critical survey of hydroxo complexes of beryllium in aqueous and aqueous mixed solvents

Abstract: Die hydrolytischen Reaktionen des Be-Ions in Wasser-Methanol-,Wasser-Athanol und Wasser-Aceton-Losungen (alle mit 0,2 Molenbruchen der organischen Komponente und 3m an LiClO4) werden bei 25°C titrimetrisch untersucht.