[en] The polarographic behaviour of uranyl ion in maleic acid solution shows two reduction waves. The half wave potential of the first wave is shifted to more negative values in contrast to that of the second wave, which is shifted to less negative potentials on increase of the pH of the solution. The first wave represents the reduction of the 1:1 uranyl-maleate complex, while the second wave represents the reduction of the 1:2 complex. The presence of 1:1 and 1:2 complexes is supported by spectrophotometric and conductometric methods. The stability constants were also determined and the reduction mechanism is discussed. (Author)

[en] The complexes of niobium(V) with 2-phenyl-1, 1, 3, 3-tetraacetylpropane and 2-phenyl-1, 3-diacetyl-1, 3-dibenzoylpropane were investigated by IR, UV, ¹H-NMR, and magnetic measurements. Together with analytical data and determination of molecular weights a trimeric structure is proposed for both 1:1 complexes. (Author)

[en] The electrode kinetic parameters of the In(III)/In(I) couple in acidic 4M bromide solution have been determined by means of the rotating disc electrode technique. (Author)

[en] The mechanism of the indium electrodeposition on gold from acidic KBr solutions has been investigated by means of the rotating ring-disc electrode technique. The measurements showed that the overall electrode reaction In(III) + 3e → In consists of two successive charge transfer steps, i.e. In(III) + 2e → In(I) and In(I) + e → In, with soluble monovalent indium as an intermediate. The current efficiency for In(I) generation under steady-state conditions is 100% in the case of low disc surrent densities. The disproportionation of In(I) in the bulk of solution occurs in slightly acidified solutions, pH=2, in addition to the In(I) electrochemical reduction. Based on the ring current transients, it was established that the two-electron transfer step is preceded by the formation of a thin passive film of indium metal. (Author)

[en] The kinetics of charge-transfer interaction between p-toluidine and iodine in methylene chloride was investigated in depth. The thermal process of formation of the 'inner' complex was found to proceed to an equilibrium. The photochemical process follows a different reaction coordinate, going through the formation of an exciplex between the excited 'outer' complex and the amine ground state. In both cases the same ionic complex (Am₂I⁺I^-₃, where Am stands for p-toluidine) was detected as the final product. (Author)

[en] Reaction of Cd(II) ion with hypoxanthine (H₂Y) and with 6-mercaptopurine (H₂MP) in dioxane-water (50%) leads to the formation of CdY x 2H₂O and Cd(HMP)₂ x 2H₂O, respectively. In methanolic medium Cd(II) and H₂MP give Cd(MP) x H₂O. These compounds have been characterized by chemical analysis, IR spectra and thermogravimetric analysis. The stability constant of CdY complex at 25 +- 0.1⁰C and 1M ionic strength with NaClO₄ in dioxane-water medium is logβ = 10.25 +- 0.05. (Author)

[en] The infrared and Raman spectra of Ba₃V₁₀O₂₈.19H₂O has been recorded and an assignment for the internal vibrations of the V₁₀O₂₈^6- anion is given. Infrared data of the hydrated decavanadates of silver, cadmium, magnesium and lanthanum are also reported and briefly discussed. (author)

[en] The technique of INAA for the determination of the rare earth elements with respect to prospecting and production testing of polishing powders on the basis of rare earth element oxides as well as quality testing of ultragrade rare earth compounds is discussed. In order to count γ-radiation of the radioactive nuclei a Ge-Li-detector as well as a planar Ge-Li-detector have been used. The latter enables the evaluation of the low energetic side of the γ-spectrum without complicated corrections due to γ-line interferences. Therefore an efficient working procedure with respect to the determination of the distribution pattern of the rare earth elements is possible. A simple correction program however is necessary with respect to the use of the planar detector type, allowing for effects of self-absorption, geometry of the sample as well as distance sample-detector. This program is also given in the paper

[en] he i.r., u.v., ¹H n.m.r., ¹³C n.m.r., and ¹¹B n.m.r. spectra of several substituted diphenylboron chelates derived from salicylaldehyde azomethines were compared with respect to the influence of the amine substituent R. O-B-N-6-ring constitution of the chelates 29-32 [R = OH, NH₂, NHC₆H₅, N(CH₃)₂] can be deduced from the spectra. (author)

[en] Raman spectra of some solid and molten PCl₅-ZrCl₄ mixtures have been recorded. ZrCl₆^2- complex ions accompanied by at least one more chlorozirconate species are present in the solid as well as in the melt. The new Raman frequencies are attributed to ZrClsub(5-), which fundamentals are given and assignment is proposed to be analogous to TiClsub(5-). The presence of ZrCl₆^2- and ZrClsub(5-) can be explained by the equilibrium ZrCl₆^2- + PClsub(4+) reversible ZrClsub(5-) + PCl₅. (auth.)