Reaction of isonitrosoacetylacetone (Hinaa) with CuX₂^.nH₂O, (X = CH₃CO₂, Cl or NO₃, n = 1, 2 or 3) led to complexes of types (inaa)₂Cu^.3H₂O and (Hinaa)₂CuX₂^.H₂O, (X = Cl or NO₃). The octahedral complexes have been postulated due to elemental analysis, IR, VIS-U.V spectra, magnetic susceptibility, conductivity and ESR spectra. Molar conductance of the complexes in DMF indicates non-ionic character. ESR spectrum of (inaa)₂Cu^.3H₂O in CD₃OD/D₂O (10%) at 77 K shows axial type symmetry (d_x2-y2). However, the spectrum of the solid (Hinaa)₂CuCl₂^.H₂O at room temperature with g_perpend >> g_|| >> 2.002 indicates a compressed tetragonal distortion along the Z-axis with the unpaired electron in d_z2 orbital.

DC and DP polarography were used to study the reduction of Co(II) in the presence of potentially terdentate diamino acids (2,3-diaminopropionic acid, 2,4-diaminobutyric acid, histidine). The stoichiometry of the species discharging on a mercury electrode and the relevant electrochemical kinetic parameters were determined. The electrochemical behaviour of particular species strongly depends on the donor system bound to the metal ion.

Chlorolysis of pyrimidinethione 1 yielded chloropyrimidine 3, which reacted with arylamines to yield 4-arylaminopyrimidines 4a-c. Compounds 4a,b were condensed with benzaldehyde to afford pyridopyrimidines 6a,b, which underwent cyclization to pyirmidoquinazoline 7. Compound 3 reacted with ethyl glycinate to give pyrrolopyrimidine 9. Chloropyrimidine 3 reacted with acid hydrazide to afford hydrazides 10a,b that underwent intramolecular cyclodehydration to triazolopryimidine 11. Synthesis of furopyrimidine 13, thienopyrimidine 14 and 4-ethoxypyrimidine 15 was also described.

Thirty three new 2- and 2,7-substituted iodonium/diiodonium salts derived from xanthene, xanth-9-one, fluorene, and fluoren-9-one are reported in this paper. Their structures were supported analytically and by their ¹H NMR and IR interpreted spectra.

Novel bromo and iodo substituted 2-alkyl-2,3,4,5-tetrahydro-1,4-benzoxazepine-3,5- -diones 5 have been prepared by cyclodehydratation of 2-(2-carbamoilphenoxy) alkanoic acids 4 and as the result of the reaction of halogenated salicylamides 1 with 2-bromo

High antifeedant activity of isovellerol, a gamma-hydroxy-aldehyde sesquiterpene of marasmane skeleton prompted us to synthesize the same type of compounds with the isolactarane skeleton, and to check their antifeedant activity. LiAlH₄ reduction of isolactarorufin gave the desired compound, besides the tetraol (a compound with open lactone ring). Extensive spectroscopic investigation (including X-ray) indicated that the desired gamma-hydroxy-aldehyde in chloroform solution existed in the cyclic (lactol) form. Antifeedant activities of both compounds against the storage pests were moderate.

Stability of spherical and rod-like micelles of cationic surfactants in aqueous salt solutions have been treated on the basis of a statistical thermodynamic theory, corrected by incorporation of the micellar surface energy term. The modified equations for the double logarithmic relationship between micellar aggregation number and ionic strength of the solution have been derived. The newly derived equations have been applied to aqueous sodium halides solutions of dodecylpyridinium halides including those of chloride, bromide and iodide. Effect of salt concentration on the degree of ionization and the energy of hydration of both spherical and rod-like micelles have been demonstrated. Degree of ionization of the micellar associates decreases with increasing salt concentration for all surfactants studied. Energy of hydration of both spherical and rod-like micelles is negative and it increases with increasing salt concentration.

Monolayer films of binary systems were investigated with reference to miscibility of the components described in terms of excess surface area, A^exc, and excess free energy of mixing, DELTAG^exc. The binary systems contained at least one component able to generate nonlinear optical effects or (and) to show semiconductive ability. The materials tested were: poly(n-octadecylthiophene), p-(1-n-octadecylpyrryl-2-azo)benzenesulfonic acid, (p-(1-n-octadecylpyrryl-2-azo)benzoic acid, and 2,4-dinitrophenylhydrazone of 3-n- -octadecanoylpyrrole. As film builders there were used 1-n-octadecylimidazole and 3-n-octadecylpyrrole. On the basis of surface excess area, A^exc, and surface excess free energy, DELTAG^exc, the regions of positive synergic interactions between film components were determined.

The kinetics of complex catalytic reaction of A -> B -> C type proceeding in the presence of decaying catalyst in a batch reactor is discussed. Calculated model correlations between reactant conversions and reaction time/total conversion were used to analyze n-pentane transformation in the presence of solid superacid Al₂O₃-SbF₅ catalyst.

The adsorption of n-octylamine, n-dodecylamine, n-hexadecylamine and n-octadecyl-amine on a polarized Au electrode from LiClO₄ methanolic solutions has been studied by capacity measurements. Some adsorption parameters for the potential near to the potential of maximum adsorption have been calculated, according to Frumkin's and Damaskin's theory. A discussion of the results connected with the literature data concerning the adsorption of alcohol molecules has been provided.

Rate constants for the reaction of 1-chloro-2,3-epoxypropane with n-, sec-, tert-butyl, n-hexyl, n-octyl, and n-decyl alcohols in the presence of boron trifluoride were studied at 30, 40, and 50^oC. The reaction rate is first order with respect to 1-chloro-2,3-epoxypropane and independent of alcohol concentration. The rate constant is proportional to the catalyst concentration. The rate constants increase in the homologous series of C₄-C₁₀ alcohols. The reaction rates of 1-chloro-2,3-epoxypropane with 1-alkoxy-3- -chloro-2-propanols are considerably larger than that with corresponding alcohols.

The capillary model of transport through charged membranes has been reformulated by transport equations of non-equilibrium thermodynamics. Two geometries of pores has been considered - a capillary and a slit. It has been assumed that the distribution of mobile components is governed by the zero components of forces in the plane perpendicular to the direction of transport. It has been shown that the part of transport coefficients, describing the motion of the center of mass, depends on the distribution of species inside the capillary and on the viscosity of the solution. The transport coefficients, averaged over the cross-section, are symmetrical.

The reaction of hydrodechlorination of CF₂Cl₂ was studied in the presence of similarly dispersed alumina-supported palladium catalysts. Catalytic activity of alpha-Al₂O₃- and gamma-Al₂O₃-supported palladium does not depend on the fact, which type of alumina was used as a support. However, palladium supported on alpha-Al₂O₃ appeared more selective towards CF₂H₂ than Pd/gamma-Al₂O₃. Since alpha-Al₂O₃ is markedly less porous carrier than gamma-Al₂O₃, lower selectivity towards partial hydrodehalogenation on Pd/gamma-Al₂O₃ may result from a consecutive reaction of CF₂H₂ to methane. High temperature pretreatment supposedly eliminates narrow pores in gamma-Al₂O₃, what, in consequence, leads to higher selectivity to CF₂H₂. Carbiding palladium surfaces takes place during the reaction. After carbon removal, Pd/Al₂O₃ shows a similar catalytic behaviour as fresh samples.

Two major force fields (Tripos and MMX) were used to calculate three dimensional structures, steric energies and Boltzmann distribution of low energy conformers of 1,25-dihydroxycholecalciferol and its A-ring analogs. Molecular modelling revealed that out of a series of analogs substituted at carbon atom C(4), (4R)-4-methyl-1,25-dihydroxycholecalciferol might be expected to exist in a solution preferentially in a ß-type of conformation of an A ring. This analog, compared to the (4S) isomer, is to be used for further structure - activity study of the ß-type conformation of an A-ring as a hypothetical active form in which vitamin D compound interacts with vitamin D receptor.

The gauge-independent atomic orbital (GIAO) approach has been used within the coupled Hartree-Fock approximation to compute ¹H and ¹⁴N NMR shielding constants in selected ion pairs of solid NH₄NO₃. Assuming additivity of intermolecular effects the shielding constants of NH₄⁺ ions in two different polymorphic forms of ammonium nitrate have been determined. According to our calculations condensation of NH₄NO₃ leads to small deshielding effects for ¹H and ¹⁴N nuclei. Geometry of the central NH₄⁺ cation is the most important factor influencing results of calculations of nuclear shielding constants. This geometry reflects the role of intermolecular interactions in the crystal lattice. Our results show that the GIAO approach at the Hartree-Fock level differentiates two polymorphic forms of ammonium nitrate. Some results on temperature dependences for ¹H and ¹⁴N shielding constants are included. There is a linear dependence between the ¹H and ¹⁴N shielding constants.

The non-isothermal system of copper electrodes in aqueous solution of CuCl₂ + HCl has been studied. The interval of HCl concentrations with a linear dependence of non-isothermal electromotive force (emf) on the temperature difference has been determined. Thermoelectric potentials and phenomenological coefficients have been evaluated. The contribution of particle fluxes caused by temperature gradient to the total flux of charged particles is estimated to 15-20%.

Precise lattice parameters of antimony sulfoiodide SbSI single crystals have been determined by the Bond method between 95-460 K. Apart from the ferroelectric phase transition at 298 K, a high temperature phase transition was found at 410 K. In the ferroelectric phase the lattice parameter c increases with decreasing temperature and reaches the maximum value at about 150 K. There is also a small anomaly of the temperature dependence of lattice parameter a, which increases below the Curie point, reaches the maximum value at 290 K and decreases at lower temperatures. No anomalies of thermal expansion were observed between 210-260 K, where a low temperature phase transition was reported by some authors.

Diaquobis(3-aminopyrazine-2-carboxylato-N,O)magnesium(II)monohydrate, MgC₁₀H₁₄N₆O₇ crystallizes in the monoclinic system, space group Cc. Lattice parameters: a = 12.225(5), b = 8.286(1), c = 15.964(2) Å, ß= 112.50(3) deg., Z = 4. The structure is composed of monomeric molecules. The Mg⁺² ion is coordinated by two acid molecules and two water molecules. The coordination octahedron of the Mg⁺² ion consists of two heteroring nitrogens (Mg-N = 2.255 Å) and two oxygen atoms belonging to two monodentate carboxylic groups (Mg-O = 2.070 Å) donated by two acid molecules plus two oxygen atoms of water molecules (Mg-O = 2.040 Å). A network of hydrogen bonds is operative between the monomers and solvation water molecules.
Crystals of 3-aminopyrazine-2-carboxylic acid, C₅H₅N₃O₂ belong to the monoclinic system, space group P2₁/c. Lattice parameters: a = 3.751(1), b = 14.184(3), c = 10.906(2) Å, ß = 99.17(3) deg., Z = 4. The structure contains two-dimensional molecular layers in which the molecules are held by short hydrogen bonds of 2.765 Å. They join the carboxylic oxygens and the heteroring nitrogens of the adjacent molecules to make zig-zag chains. Additional weak interaction with the distance of 3.112 Å operates between the aminogroup nitrogen and the heteroring nitrogen. Every second pair of molecules belonging to the adjacent chains is linked by two weak hydrogen bonds of 2.997 Å. The interlayer spacing is 3.751(1) Å.

The crystals of monoaquabis(miu-3-amino-2-pyrazinato)calcium(II) are monoclinic, space group Cc, a = 22.787(5), b = 6.367(1), c = 9.906(2) Å, ß = 110.58(3) deg., Z = 4. Each calcium atom is coordinated by two aminopyrazinate molecules via their heteroring nitrogens (Ca-N = 2.594 Å ) and the nearest to them two oxygens of the carboxylate groups (Ca-O = 2.385 Å) and by one water molecule with Ca-O = 2.344 Å, making with aminopyrazinate ligands a planar "step". Two other oxygen atoms are chelated to the calcium atom, each contributed by the second oxygen atom of the carboxylic group situated in the "step" above and below (mean Ca-O = 2.363 Å). The carboxylic groups are bidentate and bridge the "steps" into ribbons propagating along the c axis. The ribbons are linked by strong hydrogen bonds of 2.71(1) and 2.74(1) Å operating between the coordinated water oxygen and the carboxylic oxygens in the adjacent ribbons.