[en] Studied is the crystal structure of K₃Nb(SO₄)₄ with the Pnma symmetry and cell parameters a=8.078, b=12.63, c=14.71A, Z=4, rhosub(exp)=2.65g/cmsup(3), rhosub(roent.)=2.66g/cmsup(3). It is island structure. Coordination polyhedron of niobium is dodecahedron, Nb-0 distances are 2.05-2.20A. All three crystallochemically independent sylfate groups are bidentat- cyclic groups. [Nb(SO₄)₄]^3- anions are bind with potassium ions

[en] The non empirical calculation of equilibrium geometry and force field of the basic electron state of boron oxide molecule is carried out. For the equilibrium geometrical configuration found vertical energies of transitions into excited states, electric moments and diamagnetic susceptibility are calculated. On the basis of results obtained the comparable analysis of experimental and theoretical data for the B₂O₃ molecule is performed

No abstract available

No abstract available

No abstract available

[en] The ¹H and ¹⁹F NMR data have been used to study hydrogen bond geometry in the CaF₂x2HF, SrF₂xHF, BaF₂xHF hydrofluorides. Determination of structural parameters of the hydrogen bond has been carried out by means of numerical analysis of NMR line shape of polycrystal samples. It is established that boron and strontium hydrofluorides contain weakly asymmetric bifluoride ions. The bifluoride ion in calcium hydrofluoride is symmetric. The H-F and F-F distances are determined, which are (with account for oscillation ammendments), respectively. 1,143+-0,02 and 2,286+-0,004 A for CaF₂x2HF, 1,O90+-0,0O7 and 2,277+-0,004A for SrF₂xHF and 1,089+-0,004 and 2,301+-0,004 A for BaF₂xHF

[en] Obtaining laminated graphite compounds (LGC) which contain both FeCl₃ and MoCl₅ or FeCl₃ and WCl₆ is described. Data on diffractometric investigation of these compounds are presented. The method of gamma-resonance spectroscopy (GR) is used to show that in LGC with FeCl₃-MoCl₅ iron has two form: Fe²⁺ and Fe³⁺. F²⁺ content in LGC rises with the increase of Mo/Fe ratio GR parameters of this form show that FeCl₂ forms a joint structure with molybdenum fluoride in graphite interlayer space. FeCl₂ presence in graphite may be connected with FeCl₃ reduction outside graphite and its introduction into graphite at the expense of a transport reaction through gaseous complexes of the FeMo₂Cl₁₂xFeCl₃ type also forms a joint structure with MoCl₅ in graphite interlayer space. Formation of FeCl₂ as well as joint structures between FeCl₃ and WCl₆ in LGC FeCl₃-WCl₆ does not occur

[en] Measured are relaxation times T₁ and T₂ of ⁹³Nb nuclei depending on the temperature in [NbClsub(n)Brsub(6-n)]sup(-) octahedron complexes (n=0-6) that are simultaneously present in acetonitrile solution. It is found out that relaxation rate in all complexes, except cis-[NbCl₃Br₃]^-, is determined by quadrupole interactions. In cis-[NbCl₃Br₃]^- anion the relaxation mechanism is conditioned by exchange processes connected with intramolecular cis reversible trans-isomerization. Resonance signals were regarded as definite isomers on the basis of T₁ and T₂ data. Changes of diamagnetic and paramagnetic constituents of ₉₃Nb nuclei screening constant are calculated depending on the coordination sphere composition. ₉₃Nb chemical shifts in the [NbClsub(n)Brsub(6-n)]sup(-) series are shown to be determined by paramagnetic constituent of the screening constant

No abstract available

[en] The semiempiric Mallikan Wolfsberg Helmholtz method has been applied to investigate the electron structure and to give the interpretation of X-ray emission spectra of RVO₄ vanadates (where R=Y, Sc, Tb, Dy, Nd, Er, Eu). Calculation data and the X-ray spectra obtained show that the VO₄^3- grouping in vanadates is isolated to a great extent