[en] The stochastic theory of Moessbauer line shapes is formulated in a fashion which allows the evaluation of the spectral shapes for absorbers of arbitrary thickness, texture, and an anisotropic Lamb-Moessbauer factor. The results are specialized to a two-state-relaxation model of fluctuating electric hyperfine interaction in the case of an absorber of axially symmetric texture. The formalism is applied to the line shape analysis of Moessbauer spectra of a textured sample of the spin-crossover complex [Fe(mtz)₆](PF₆)₂ (mtz = 1-methyltetrazole). It is found that between 185 and 240 K the rate constants for the HS → LS conversion are temperature independent, whereas an Arrhenius behaviour is found for the LS → HS conversion

[en] Specific nonvalent interactions (SNI) with participation chalcogene atoms in structures on the basis of (μ₃-X)(μ₂-X₂)₃M₃⁴⁺ and (μ₃-X)(μ₂-X)₃M₃⁴⁺ (M = Mo, W; X = O, S, Se) were considered. SNI classification was carried out. The determining role of SNI during crystal structure formation was shown

[en] The modern state of the theory of the mutual influence of ligands (MIL) has been analyzed and conclusions from the different MIL models have been compared with experimental data concerning the central atom-ligand bond lengths. It is shown that in complexes of both transition and main group elements the predominant type of the directed influence of ligands is the trans-influence, though in some cases, especially for main group element complexes, the MIL regularities are of a more complicated character. (author)

[en] Binuclear molybdenum(0) carbonyl complexes were synthesized based on naphthophosphacyclophanes containing a 1,6-dihydroxynaphthalene fragment and diethylamide linkers. The physicochemical and spectral characteristics of the synthesized coordination systems were studied.

[en] Absolute gf-values for nine resonance lines of Sc I have been experimentally measured by the atomic-beam method. Difficulties in evaporation of scandium were overcome by using a tantalum boat. These gf-values can be used to put more extensive measurements of relative gf-values on an absolute scale. Comparisons are made with other determinations of absolute gf-values for Sc I. (author)

No abstract available

[en] Using theoretically-group analysis and quantum-chemical calculations possibility of existence of flat-square complexes [M₄C] and [M₄C]^2- (M=Al, Ga, In, Tl, Sc, Y) in gaseous phase is shown. It is possible to separate a flat-square carbon complexes Kt₂[M₄C] in crystalline state. More high stability of such complexes in comparison with ordinary tetrahedral ones is achieved by formation of five- and four-center bonds (M-M and M-C)

[en] Short communication. 2 refs

[en] The bonding in O₃M-M(CO)₅ has been studied by ab initio SCF, two-configuration SCF, and CI methods for M = Re and Tc. Calculations indicate that these complexes are highly polar. The nature of the charge transfer in these complexes is considered

[en] Using the methods of saturation and isomolar series the mixtures of type (M-P₂W₁₇O₆₁^10-) (M = Mn, Fe, Cr, Ni, Co, Cu) have been studied to determine stability constants of complexes of transition metal ions with the 2:17 unsaturated heteropolyanion [P₂W₁₇O₆₁]^10-