The complexes of Cu(II) with 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole and 3-amino-5-methylthio-1,2,4-triazole have been prepared and characterized by metal and CHN analyses, infrared and visible spectral and magnetic susceptibility data. It has been found, that the first two ligands form mononuclear species, while the third ligand forms the polynuclear complex. All the complexes have pseudo-octahedral configuration with a tetragonal distortion.

The complexes of Y(III) and heavy lanthanides(III) (Gd-Lu) with 2,6-dihydroxybenzoic acid have been prepared and their IR spectra, solubilities in water and thermal decomposition have been investigated. The complexes [Ln(C₇H₅O₄)₃(H₂O)₄]^.2H₂O, when heated, lose their crystallization water in two steps and then decompose to the oxides Ln₂O₃ and Tb₄O₇ with intermediate formation of Ln(C₇H₅O₄)(C₇H₄O₄). In the complexes prepared, the carboxylate groups act as monodentate and bidentate chelating ligands. The water molecules are linked in inner and outer spheres. The complexes of Y(III) and heavy lanthanides (Gd-Lu) are isostructural.

Azobenzenes with para-dimethylamino group at aromatic ring and various para substituents to another phenyl have been studied by ^{13C CP MAS NMR spectroscopy followed by semi-empirical AM1 MO calculations. The locked trans-configuration around N=N bond in the solid state results in non-equivalence of ortho carbons (C2 and C6, also C2' and C6') and the difference in chemical shifts is 12.9-22.0 ppm. The separation of meta carbons resonances is less manifested but in 1, 3, 4, 8 the non-equivalence of C3' and C5' is enhanced by the orientation of X-substituents at C4'.}

A 29-peptide, [Pen^{3,10,16,20,22,28}]CMTI-III, an analogue of Cucurbita maxima trypsin inhibitor from squash seeds was synthesized by the solid phase method using the Fmoc chemistry. The inhibitory activity of the analogue, as measured by the association equilibrium constant (K_a) with bovine -trypsin, is of the same order of magnitude as that for the wild CMTI-III.

Reactions of N-aryl-N-(4,5-dihydro-1H-imidazo-2-yl)-hydroxylamines 1a-d with methanesulfonyl chloride in the presence of triethylamine afforded 2,3-dihydroimid-
azo[1,2-a]benzimidazoles 2a-d. The latter compounds treated with acetic anhydride, methane or phenylsulfonyl chlorides gave N-1 acetyl or N-1 methane or phenylsulfonyl derivatives 3a-d and 4a-b, respectively.

Reactions of 1,4-naphthoquinone with aza-ortho-xylylenes generated via thermal extrusion of SO₂ from 2,1-benzisothiazoline 2,2-dioxides (benzosultams) lead to tetrahydronaphthalene-2-spiro-2'-dihydroindole derivatives. Aza-ortho-xylylene generated via thermal ring opening of 1-phenylbenzazetidine gave with naphthoquinone benzo[b]acridine derivative 15.

Carbon-13 kinetic isotope effects,¹³C-KIE, in the decarboxylation of phenylpropiolic acid (carboxyl C-13) in formic acid medium and ¹³C KIE in the decarbonylation of liquid formic acid assisted with PPA and acetophenone have been studied in the 70-100°C temperature interval. The kinetic and isotope results have been discussed and interpreted as indicating that the formation of C-H bond, preceded by the protonation of acetylenic bond of PPA, is the rate determining step followed by carbon dioxide splitting. The ¹³CO-KIE in the carbon monoxide generation assisted with PPA is much larger than the ¹³CO-KIE observed in the generation of CO in the presence of phenylacetylene. Thus the decarboxylation of PPA and decarbonyl

The complex formation of cadmium(II) with ethylenediaminetetraacetate (H₄Edta), iminodiacetate (H₂Imda) and glycine (HGl) has been studied by chronopotentiometry. It has been found that cadmium(II) forms with the above ligands complex ions of the compositions: CdHEdta^-, CdEdta^2-, CdImda, Cd (Imda)₂^2- CdGl⁺ and CdGl₂. The stability constants of the above complexes have been determined.

ZSM-5 zeolite modified with Nb was investigated by XRD, IR and MAS NMR spectroscopies. Niobium atoms were introduced by calcination of NH₄ZSM-5 zeolite with Nb₂O₅. The last samples showed Broensted and Lewis acidity and can catalyse m-xylene ammoxidation to nitriles. Thermal treatment of ZSM-5 and Nb₂O₅ mixtures leads to dealumination of zeolite framework. The addition of Nb₂O₅ decreases the amount of aluminium atoms eliminated from the lattice and preserves the framework.

The electrochemical reductions of some recently synthesized 1,8-dihydroxy-9,10-anthraquinone derivatives in acetonitrile were investigated. In the absence of proton donors, the anthraquinones reduced in two successive one-electron steps. The first step is reversible or nearly reversible, while the second step is quasireversible or irreversible, depending on the electrode used. The influence of molecular structure on the reduction potential is addressed. The diffusion coefficients of the anthraquinone derivatives were determined from chronoamperometric measurements on the GC, Au and Pt electrodes. The heterogeneous electron transfer rate constants and charge transfer diffusion coefficients were evaluated from rotating disc voltammetry measurements. Dependence of the rate constants on the anthraquinone structure and the electrode materials is discussed.

The electrooxidative polymerization of nickel complex of 1,5- diaminonaphthalene was performed in acetonitrile containing lithium perchlorate, using cyclic voltammetry and controlled potential electrolysis. The film coated electrode showed an electroactive redox response in acidic aqueous solutions only. The stability of the redox response towards repetitive cyclic voltammetry was studied. The formal redox potential of the resulting film electrode was about 0.28 V vs. Ag/Ag⁺ in 1.0 M acidic chloride aqueous solution (pH = 0). The electrical conductivity of the film was measured in 0.01 M KC1 aqueous solution and was found as (2.2 ± 0.02) × 10^-4 S cm^-1. The morphology of the film and the factors affecting its electroactivity were studied in detail.

Metal-support interactions in silica-supported palladium catalyst have been re-investigated. In addition to the already recognized model reaction of 2,2-dimethylpropane with hydrogen, where the isomerization selectivity appears as a useful indication in diagnosing changes in the catalyst, another effective probe has been used: a variable capability of differently modified palladium to form the hydride phase. High temperature reduction at 600°C of 1.6 wt% Pd/SiO₂ results in the formation of palladium silicide. However, the prove of this fact by X-ray diffraction is ambiguous or impossible, because of a low content of highly dispersed Pd-containing phase. On the other hand, the formation (stability) of Pd hydride provides an interesting diagnostic tool: Pd/SiO₂ transformed into Pd silicide does not form the metal hydride phase. The stability of the Pd hydride phase and the catalytic conversion of 2,2-dimethylpropane are complementary methods in probing silica-supported palladium catalysts.

During oxidation of n-butane to maleic anhydride on VPO catalysts phosphorus is carried out from the catalyst by gas phase. The transport medium is likely an organic compound of phosphorus. An active role of phosphorus in the n-butane transformation is suggested.

A new evaluation of kinetic parameters of the thermal degradation of cross-linked polymers is proposed. The DTG-peaks separation is the base for this method. The application of this approach to thermal degradation of epoxypolymers is discussed with respect to chemical transformations and structure of the polymer matrix.

Reduction of surface oxide preformed on unsupported and alumina supported Cu-Ni alloys was examined at a linearly increasing temperature. The obtained TPR spectra exhibited two peaks of H₂ consumption, connected with the reduction of surface copper and surface nickel oxides. The size of these peaks was used to estimate surface compositions of the alloy. The results obtained agree with the surface composition calculated from a semiempirical equation.

The crystal and molecular structure of the antibacterial compound Nifuroxazide was carried out by X-ray diffraction methods. The crystals belong to the triclinic system, space group P1. The lattice parameters are: a = 6.879(6) , b = 8.164(5) , c = 11.410(7) , = 78.87(5)°, = 78.91(5)°, = 69.68(7)°. The molecule is essentially planar except of the phenyl ring somewhat twisted with respect to the residual part of the molecule. In the crystal structure, the molecules are hydrogen bonded, forming infinite planar sheets.