The molecular structure, energetics and vibrations have been calculated for the MO₂ moiety in the M(O₂)X(YH₃)₃ series of metal dioxygen complexes at three levels of theory: ab initio (RHF/3-21G**), DFT (B3PW91/3-21G**) and semiempirical PM3(tm). The methods yielded the O-O distances consistent with the experimental values and similarly predicted the tendencies of geometrical parameters to change. The variation of the enthalpy of formation with the central metal atom, halogen and ligand seems to be in qualitative interconsistency, whereas changes in the MO₂ moiety frequencies, found at different levels, disagree substantially.

New complexes of 2,4'-bipyridine (2,4'-bipy or L) with iron(II) of the formulae FeL₂Cl₂^.2H₂O, FeL₂Br₂^.2H₂O, FeL₂(NCS)₂^.H₂O, FeLSO₄^.5H₂O, FeL₄(ClO₄)₂^.2H₂O and FeL₄(ox)^.2H₂O (ox = C₂O₄^-) have been prepared and their magnetic, spectroscopic, molar conductivity and thermal properties studied. IR measurements show that the 2,4'-bipy behaves as a monodentate ligand. During heating the hydrated complexes lose all crystallization water and next decompose via different intermediate products to Fe₂O₃.

Coordination compounds of Pd(II) and Pt(II) with 3,4,5,6-tetrahydro-2-pyrimidinethiol (THPT) of the general formula M(THPT)₄Cl₂^.H₂O, where M stands for Pd and Pt, have been obtained and characterized by elemental analysis, X-ray diffraction patterns, derivatography (TG, DTG, DTA), magnetic measurements, and the IR and far-IR spectroscopy. Crystal and molecular structure of the Pd(THPT)₄Cl₂^.H₂O have been determined. This compound crystallizes in the monoclinic system with a = 8.555(2), b = 14.999(3), c = 23.324(5), = 91.05(3)°, V = 2832.7(11) ³ and Z = 4; space group P2₁/c. The two compounds have been found to be isostructural.

The tetrachlorocuprate(II), tetrabromocuprate(II) and tetrakis(izothiocyanate)cuprate(II) complexes of diantipyrylmethanium cations have been prepared and formulated as (H₂DAM)CuCl₄, (H₂DAM)CuBr₄ and (HDAM)₂Cu(NCS)₄ on the basis of spectral data (IR, UV-VIS) and elemental analysis. The EPR spectra, variable temperature magnetic susceptibility and thermal properties in air have been investigated. The results indicate for all complexes a distorted tetrahedral configuration. All studied complexes exhibited Curie-Weiss behaviour between 80-300 K. Thermal decomposition is a multistage process and yields CuO as final product.

A method for the acetylation of the exocyclic amino group of guanine derivatives has been developed. A series of N²-acetylguanines was synthesized by reacting of N₉₍₇₎-alkoxyalkylguanines with an excess of acetic anhydride in the presence of 4-dimethylaminopyridine. The method has been used successfully also for N²-acetylation of guanosine and its 8-bromo derivative although in the latter case a partial substitution of bromine for a hydroxy group at the position 8 of the heterocycle occurred.

Tetrazole and its 1- and 5-monosubstituted derivatives are found to react with tert-butyl alcohol in 72% perchloric acid media, yielding selectively 1,3-di- and 1,3,5-trisubstituted tetrazolium salts. 1,3-Disubstituted salts are slowly converted under the same conditions into the corresponding 1,4-disubstituted salts. This transformation may be used for selective synthesis of the latter.

A series of novel 2-(2-carboxyphenoxy)alkanamides 4a-f have been obtained as result of condensation of salicylaldehydes with 2-halo esters, amination of prepared esters 1a-f with methylamine followed by oxidation of amides 3a-f with sodium chlorite. The intramolecular cyclization of amides 4a-f to 1,4-benzoxazepin-3,5-dione system has been investigated.

The kinetics of oxidation of -hydroxy acids (mandelic, lactic and glycolic) with a recently developed new mild Cr(VI) reagent quinolinium fluorochromate (QFC) has been investigated in perchloric acid medium. First-order dependence with respect to [oxidant] is observed. Increase in [substrate] increases the rate proportionally. The acidity dependence is fractional order throughout the entire range of acidities studied. Decrease in dielectric constant of the medium increases the oxidation rate considerably. Kinetic solvent isotope effect studies indicate a pre-equilibrium fast proton transfer. Absence of polymerization with acrylonitrile rules out a free radical mechanism. An intermediate formed between protonated oxidant and substrate decomposes in a slow rate-limiting step giving the products.

The reaction between pyridinium chlorochromate and As(III) was studied in hydrochloric acid medium. The reaction was found to be overall second order and the added product As(V) was found to decrease the rate. The hydrogen ion was found to catalyse the reaction and it was predicted that both protonated and free pyridinium chlorochromate are active to a different extent. The active species of the reductant was H₃AsO₃ and the mechanism is dicussed in terms of these species. The retardation by the added product is predicted to be due to a competitive ester formation.

A classical finite differences algorithm of simulation of electrode processes was applied for strict modelling of electrochemical oscillations induced by interplay of ohmic drops and negative polarization resistance of the charge-transfer process. The linear and spherical geometry of diffusion was implemented. A numerical way of incorporating constant and potential-dependent double layer capacitances is described. Examples of shapes of oscillations and associated full diffusion profiles of electroactive species are presented. A comparison of this strict modelling of oscillations and typical approximated way of calculations, suggesting the importance of precise calculations, was outlined.

The formation constants, K_s, for 1:1 complexes of the cis-syn-cis and cis-anti-cis isomers of dicyclohexyl-18-crown-6 with sodium and potassium cations have been electrochemically determined in 10 nonaqueous (protic and aprotic) media. Linear correlations were obtained for log K_s with standard Gibbs transfer energies of the cation from water to a given solvent. The cis-anti-cis isomer was found to be a weaker complexer than the cis-syn-cis one and this was elucidated in terms of the ligand solvation. Energy-minimized structures of the ligands and complexes surrounded by methanol and acetonitrile molecules were established by molecular dynamics computations.

Four adsorbents with chemically bounded aniline radicals on silica gel surface of concentration 2.94; 5.86; 6.47 and 7.81 µ mole/m² were prepared. On packed chromatographic column with unmodified silica gel Si 100 and obtained adsorbents the retention times of aliphatic (C₆-C₁₂) and aromatic (benzene, toluene and m-xylene) hydrocarbons and polar organic compounds (chloroform, ethylene chloride, chlorobenzene, p-chlorotoluene and ethyl benzene) were measured. Retention times, obtained on column with packing of the highest concentration of the bounded phase, were shorter than those on column with unmodified silica gel Si 100. Thus, there exists a possibility of optimization of retention of chemical compounds by change of their phase concentration on the support surface.

Polymeric materials such as: poly(n-octadecyl methacrylate), poly(n-octadecyl metha-crylate-co-N-p-nitrophenylmaleimide) and poly(n-octadecyl methacrylate-co-N-p-nitrophenylacrylamide) were synthesized to investigate their ability for monolayer film formation and deposition. It was found that polymerization of n-octadecyl methacrylate yielded the material with improved ability of film formation as compared with the monomer, and the surface pressure-area isotherm showed a distinct solid film phase formation with a high value of film collapse pressure of ca. 56 mN/m. The incorporation of a co-monomer resulted in a shift of the surface pressure isotherm towards higher area values, still with a distinct solid film phase region and high film collapse pressure. The thickness of the poly(n-octadecyl methacrylate) film deposited onto a solid subphase was ca. 3 nm per monolayer (as determined by surface plasmon resonance) and this value corresponded to the length of the monomer molecule.

Kinetics and mechanism of the silver electrode reaction in six melts of the binary AgCl-NaCl system were determined at several temperatures by Electrochemical Impedance Spectroscopy (EIS) and Relaxation Method with galvanostatic perturbation (RM). The exchange current density for this electrode process ranges from 2.5 to 4.5 A cm^-2 for different melt composition. The diffusion coefficient of the silver ion and the activation parameters are also determined in melts containing 80 and 90 mol % of NaCl.

The crystal structures of 1,2,5-trimethoxy-3-(1-propenyl)benzene (D) and 1,3,5-trimethoxy-2-(1-propenyl)benzene (F) have been determined by X-ray diffraction methods. The compounds crystallize in the monoclinic system, space group P2₁/c for (D) with a = 8.173(2), b = 11.725(2), c = 12.275(2) , = 102.48(3)°, V = 1148.5(4) ³, and P2₁/n for (F) with a = 7.433(1), b = 18.225(4), c = 8.854(2) , = 108.51(3)°, V = 1137.4(4) ³. Both, (D) and (F), carry E-propenyl side chains. The double bond lengths observed in the propenyl groups of the compounds examined (1.307(3) and 1.281(4) ) deviate from the expected value (~1.34 ). The angular deformation parameters were used in the analysis of the deformations of angles in the benzene ring. The existence of intra- and intermolecular C-H^....O hydrogen bonds was observed.