Oxidative degradation of inorganic sulphides in the presence of a catalyst based on 3,3', 5,5'-tetra-tert-butyl-4,4'-stilbenequinone.

The aim of this study is to monitor the kinetics and mechanism of liquid-phase oxidation of inorganic sulphide by oxygen in the presence of a catalyst based on 3,3',5,5'-tetra-tert-butyl-4,4'-stilbenequinone. The research results point out that this reaction has a first order with respect to each reactant. The effects of temperature, initial sulphide concentration, intermediate and final oxidation products, the nature of inorganic sulphides as well as the catalyst concentration on aqueous sulphide oxidation efficiency were investigated.

DFT study of Raman spectra of phosphorus-containing dendrons built from cyclotriphosphazene core with terminal carbamate and ester groups.

The FT Raman spectra of the zero (Gv0) and first generations (Gv1) of phosphorus-containing dendrons with terminal carbamate groups and one ester function and [2-(4-hydroxyphenyl)ethyl]-carbamic acid tert-butyl ester (C) have been recorded and analyzed. The lines of free ν(C=O) bonds are not observed in the experimental Raman spectrum of C and thus association of carbamate groups by hydrogen bonds occur. The frequencies of ν(C=O) lines in the experimental Raman spectrum reveal the presence of the different types of H-bonds in the amorphous state of Gv0.

Antimicrobial activity of imidazo[1,5-a]quinoxaline derivatives with pyridinium moiety.

3-Phenyl(methyl)-5-alkyl-1-(pyridin-3-yl)imidazo[1,5-a]quinoxalin-4-ones (2a-f) and their N-alkyl-pyridinium salts (3a-o), including 1,n-bis{3-(3-phenylimidazo[1,5-a]quinoxalin-4(5H)-on-1-yl)pyridinium}alkane dibromides (4a-d, 5, 6) have been synthesized. It has been established that the antimicrobial properties of imidazo[1,5-a]quinoxaline derivatives are connected with the presence of various alkyl substituents in the position 1 of the pyridine ring and in the position 5 of the imidazo[1,5-a]quinoxaline system. Chlorides and iodides are more active towards bacteria than fungi.

Synthesis and antimycobacterial activity of novel 1,3-dimethylisocyanurate derivatives.

A series of novel 1,3-dimethylisocyanurates has been synthesized as potential inhibitors of β-ketoacyl synthase in mycobacteria. Most of the 25 compounds described and tested for their activity against M. tuberculosis have a bacteriostatic effect, comparable and even higher that of first-line antituberculosis drugs.

The interfacial interactions of Tb-doped silica nanoparticles with surfactants and phospholipids revealed through the fluorescent response.

The quenching effect of dyes (phenol red and bromothymol blue) on Tb(III)-centered luminescence enables to sense the aggregation of cationic and anionic surfactants near the silica surface of Tb-doped silica nanoparticles (SN) in aqueous solutions. The Tb-centered luminescence of non-decorated SNs is diminished by the inner filter effect of both dyes. The decoration of the silica surface by cationic surfactants induces the quenching through the energy transfer between silica coated Tb(III) complexes and dye anions inserted into surfactant aggregates.

Electronic structure and stability of fullerene C82 isolated-pentagon-rule isomers.

All nine isolated-pentagon-rule isomers of fullerene C(82) were investigated by the DFT method with the B3LYP functional at the 6-31G, 6-31G*, and 6-31+G* levels. The distribution of single, double, and delocalized π-bonds in the molecules of these isomers is shown for the first time. The obtained results are fully supported by DFT quantum-chemical calculations of electronic and geometrical structures of these isomers.

Synthesis and photophysical properties of colloids fabricated by the layer-by-layer polyelectrolyte assembly onto Eu(III) complex as a core.

The luminescent colloids have been synthesized through the layer-by-layer assembly of poly(sodium 4-styrenesulfonate) (PSS) and polyethyleneimine (PEI) onto the luminescent core. The latter has been obtained by the reprecipitation of complex Eu[(TTA)(3)1] (where TTA(-) and 1 are thenoyltrifluoroacetonate and 2-(5-chlorophenyl-2-hydroxy)-2-phenylethenyl-bis-(2-methoxyphenyl)phosphine oxide, respectively) from organic solvent to aqueous solution. The variation of Eu(III) complexes indicates the role of the complex core in the development of such core-shell colloids.

Antimicrobial activity of pyrimidinophanes with thiocytosine and uracil moieties.

Reactions of pyrimidinophanes with two 6-methylthiocytosine and one 5(6)-alkyluracil moieties bridged with each other by polymethylene spacers with methyl or nonyl p-toluenesulfonate, p-toluenesulfonic acid, methanesulfonate and trifluorosulfonate afforded amphiphilic macrocyclic bis-p-toluene-, methane- and trifluorosulfonates. Despite the presence of several reaction centers in the initial pyrimidinophane molecules, protonation and methylation occurred only at the N(1) atom (with quaternization) of the 6-methylthiocytosine moieties. The bacteriostatic and fungistatic activity of the products was estimated.