Five new manganese(II) binuclear complexes have been synthesized, namely [Mn₂(CA)L₄](ClO₄)₂ [L denotes 2,2'-bipyridine (bpy); 1,10-phenanthroline (phen); diaminoethane (en); 1,3-diaminopropane (pn) and 1,2-diaminopropane (ap)], where CA represents the dianion of chloranilic acid. Based on elemental analyses, molar conductivity and room temperature magnetic moment measurements, spectroscopic studies, it is proposed that these complexes have CA-bridged structures and consist of two manganese(II) ions in a distorted octahedral environment. The complexes [Mn₂(CA)(bpy)₄](ClO₄)₂ (1) and [Mn₂(CA)(phen)₄](ClO₄)₂ (2) were characterized by variable temperature magnetic susceptibility measurements (4 ~ 300 K) and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, H = - 2JS₁ ^.S₂, giving the exchange parameter J = -2. 8 cm^-1 for (1) and J = -7.9 cm^-1 for (2). This result indicates that there is a weak antiferromagnetic spin-exchange interaction between two the Mn(II) ions within each molecule.

The rare earth (Y, La-Lu, without Pm) 2-amino-5-chlorobenzoates were prepared and their composition and solubilities in water at 293 K were determined (10^-4-10^-5 mol dm^-3). The complexes were obtained as solids with a 1:3 molar ratio of metal to organic ligand with general formula Ln(C₇H₅NClO₂)₃^.nH₂O, where n = 4, 5, 7 and their IR spectra were recorded. The COO^- group acts as bidentate chelating (La-Eu) or bidentate chelating and bridging ligand (Gd-Lu). During heating, the hydrated complexes lose some of their molecules of crystallization water in one step and then decompose either directly to oxides (Y, Ce, Ho-Lu) or with intermediate formation of oxochlorides LnOCl (La, Pr-Dy). The temperature of oxide formation decreases from La₂O₃ (1470 K) to Lu₂O₃ (1099 K), except of CeO₂ (849 K).

Four novel nickel(II) binuclear complexes have been synthesized and identified as [Ni₂(IPHTA)(L)₄](ClO₄)₂, where IPHTA is the isophthalate dianion and L denotes 2,2'-bipyridine (bpy); 1,10-phenanthroline (phen); 4,4'-dimethyl-2,2'-bipyridine (Me₂bpy) and 5-nitro-1,10-phenanthroline (NO₂-phen). Based on elemental analyses, molar conductance measurements, IR and electronic spectra studies, these complexes are proposed to have extended IPHTA-bridged structures and to consist of two nickel(II) ions, each in a distorted octahedral environment. The complexes [Ni₂(IPHTA)(bpy)₄](ClO₄)₂ (1) and [Ni₂(IPHTA)(Me₂bpy)₄](ClO₄)₂ (2) were characterized by variable temperature magnetic susceptibility (4 ~ 300 K) and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, H = - 2JS₁ ^.S₂, giving the exchange integral J = -17.8 cm^-1 for (1) and J = -12.5 cm^-1 for (2). These results are commensurate with antiferromagnetic interactions between the adjacent metal ions. The influence of different terminal ligands on magnetic interactions between the metals of this kind of complexes is also discussed.

The interaction between CuGaSe₂ and Cu₂GeSe₃ was studied using differential thermal, microstructural and X-ray analyses and measurements of microhardness. Polythermal CuGaSe₂-Cu₂GeSe₃ section of the quasiternary Cu₂Se-Ga₂Se₃-GeSe₂ system has been constructed. The ranges of the solid solutions have been determined.

Equilibrium phase diagram has been established from X-ray phase analysis for the ternary system Nd-Co-Si at 870 K and the crystal structure of the existing compounds has been studied by X-ray structure analysis.

Reaction of visnagin-9-phenoxysulphonyl ester and visnagin-9-N-methylpiperazinylsulphonyl with some alkyl primary amines afforded corresponding 5-alkylimine derivatives. Some visnagin-9-sulphamyl ureas and khellol carbamates were also synthesized. Antimicrobial activity of some compounds prepared was studied.

Organic phosphorothioate 7, phosphoroselenoate 8 and phosphorodithioate 9 were glucosylated with 2,3,4,6-tetra-O-benzyl-D-glucopyranose derivatives 1-6. When the reaction was performed in the presence of boron trifluoride etherate, the products were S-alpha-glucosyl and Se-alpha-glucosyl phosphoroethers 10-12. O-Benzylated glucosyl halides 5-6 with alkylammonium salt of 9 afforded S-ß-glucosyl phosphorodithioate 13, which underwent the ß ->/<- alpha anomerization by boron trifluoride etherate into more stable alpha-derivatives.

The results of molecular dynamics (MD) simulations for a simple, but realistic model of a chemical system exhibiting oscillatory behavior are presented. The period of oscillations and the phase portrait of the system obtained in simulations are in agreement with phenomenology. Two types of fluctuations seem to appear in simulations: at short time scale fluctuations depend on the size of the system, whereas at the long time scale they are related to the random motion of the MD trajectory in the phase space.

The new variant of description of a single gas adsorption on an energetically homogeneous solid adsorbent has been formulated, assuming both a partial localization of adsorption phase and a fractal character of the adsorbent. The adsorption equation, resulting from the idea presented, contains, among others, the two isothermal constants: K_H (Henry constant) and K_m-l (admolecule localization constant,) whose one-to-one dependences on temperature make various-temperature data description possible. Isotherm pencils of four adsorption systems have been described on the basis of the model proposed.

The title reaction is zero order in diperiodatonickelate(IV) (DPN) and fractional order both in [DMSO] and [OH^-]. Periodate has a retarding effect on the reaction. Effects of added products, ionic strength, dielectric constant of the reaction medium and temperature on the reaction have been studied. A plausible mechanism has been proposed and reaction constants involved are derived. Monoperiodatonickelate(IV) (MPN) and [OsO₄(OH)₂]^2- were understood to be the active species of oxidant and catalyst respectively.

The uptake of water by solid Cs₂SO₄ was investigated at 298.2 K in air of constant water activity (isopiestic method). The kinetics of this uptake was determined in the range of water activities 0.770-0.774 and especially in the neighborhood of the saturated solution. The main purpose of this paper is to compare with previous similar measurements on CsHSO₄ samples, that is comparison between systems with a congruent (Cs₂SO₄) or an incongruent character (CsHSO₄), respectively. The stationary (equilibrium) water uptake was determined in the water activity range of 0.77-0.80.

Oxidative dehydrogenation (ODH) of propane on vanadia-titania catalysts is described by a parallel-consecutive kinetic network: carbon oxides observed beside propene as the reaction products are formed mainly by successive combustion of propene and to the smaller extent by parallel to ODH total oxidation of propane. The selectivity to propene is controlled mainly by the rate of the propene oxidation. The consecutive oxidation of propene proceeds mainly by the reaction of the adsorbed propene intermediate without desorption and readsorption of propene to the gas phase. Addition of Rb to vanadia-titania catalysts decreases the values of rate constants of the various steps of the reaction, particularly those of the total combustion of propene and propane and leads also to the decrease in the activation energy of parallel total oxidation of propane. The lowering of the rate of total combustion accounts for the increase in the selectivity to propane of Rb-promoted catalysts as compared with the non-promoted ones.

The complex formation between iodine and 5,6,14,15-dibenzo-1,4-dioxa-8,12-diazacyclopentadeca-5,14-diene (DBDA15C4) has been studied spectrophotometrically in chloroform solution. The resulting charge transfer complexes characterized by microchemical analysis and IR spectroscopy are formulated as [(DBDA15C4)₂I⁺]I₃^- and [(DBDA15C4)₂I⁺]I^-. The rate constant and stability constant for the formation of [(DBDA15C4)₂I⁺]I₃^- were calculated as k = (2.71 +/- 0.04) x 10^-2 min^-1 and 5.25 +/- 0.05 M^-1, respectively. The complex shows semiconducting properties. The activation energy was evaluated as 0.88 eV.

The crystals of diaquo(m-pyrazine-2,3-dicarboxylato)calcium(II) dihydrate are monoclinic, space group P2₁, a = 6.832(1) Å, b = 16.765(3) Å, c = 8.410(2) Å, ß = 106.53(3) deg. It contains two symmetrically independent Ca ions, each coordinated by one nitrogen and seven oxygen atoms. Calcium ions are bridged in the direction of the a axis by oxygen atoms belonging to a bidentate carboxylic group of the acid molecule. The bridging in the direction of the b axis is accomplished by the same carboxylic group and by the second, monodentate carboxylic group as well as by the nearest to it nitrogen atom of the pyrazine ring (N,O-bonding moiety). In addition, each calcium ion is coordinated by two water molecules. The mean Ca-O and Ca-N bond distances are 2.441 Å and 2.645 Å respectively. Molecular sheets parallel to the (001) plane can be visualized. They are held together by strong hydrogen bonds operating via two solvation water molecules located in the space between the sheets.

The structure of racemic N-tert-butyl-3-[4-(2-methoxyphenyl)-1-piperazinyl]-2-phenyl-propanamide dihydrochloride (WAY-100135), a full 5-HT_1A receptor antagonist, was solved. The formerly postulated model, which predicts topographic requirements for the formation of bioactive complexes with 5-HT_1A receptors, was compared with the crystallographic conformation and those of the free molecule and the molecule in a simulated water environment, obtained via energy minimization by semiempirical AM1 method.

The structures of the title compounds of the D-lyxo (1) and D-arabino (2) configurations have been investigated by X-ray methods. The crystals of 1 are orthorhombic, space group P2₁2₁2₁, and of 2 belong to monoclinic space group P2₁. The unit cell dimensions are: for 1 a = 8.1789(5), b = 12.2672(7), c = 16.3720(9) Å, and for 2 a = 9.0749(7), b = 6.5655(5), c = 16.3131(8) Å, ß = 103.58(1)^o. Both structures were solved by direct methods, and refined by a full-matrix, least-squares procedure. The pyranose ring of 1 and 2 adopted ⁴H₅ conformation slightly deviated in the second compound. Relatively strong intermolecular hydrogen bonds were observed in the crystal lattice of 2.