Studies of porphyrin zinc compounds intercalated into V<Subscript>2</Subscript>O<Subscript>5</Subscript> xerogel

The intercalation of meso-tetrakis(4-pyridyl)porphyrin zinc, the cationic salts of meso-tetrakis(N-methylpyridinium-4-yl)porphyrin zinc, and zwitterionic meso-tetrakis-[N-(3-sulfonatopropyl)pyridinium-4-yl]porphyrin zinc from aqueous solutions as well as of meso-tetrakis(N-methylpyriclinium-4-yl)porphyrin zinc from pyridine solutions into V₂O₅ xerogel was studied. The intercalation complexes obtained were characterized by X-ray diffraction analysis, TG analysis, IR, and UV reflectance spectroscopy.     

Synthesis and antimicrobial activity of some acridone derivatives bearing 1,3,4-oxadiazole moiety

Novel acridone derivatives bearing 1,3,4-moiety were synthesized by intramolecular cyclization of N´-[2-(9-oxoacridin-10(9H)-yl)acetyl]arylhydrazides. Study of antimicrobial activity of the synthesized compounds reveals that some of them are more active than the comparator drug rivanol.     

Synthesis and aggregation properties of novel amino acetals with the calix[4]resorcinol platform

Reactions of calixarenes with methylaminoacetaldehyde dimethyl acetal and formalin gave Mannich bases with the calixarene platform. It was found by dielcometric titration that calix[4]resorcinols with acetal groups in the aminomethyl fragment form head-to-head supra-molecular aggregates in chloroform at low concentrations. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 888–891, May, 2006.     

Supramolecular systems formed by calix[4]resorcinarenes and surfactants in chlorophorm

Capacity titration and ¹H NOESY 2D NMR were applied to investigation of intermolecular interactions and aggregation of amphiphilic calix[4]resorcinarenes (CRA 1, 2) modified with 1,2,4-triazine (1) and oxazine (2) functions in chloroform in the presence of cationic (3) and non-ionic (4) surfactants (SAA). Critical concentrations of micelle formation (CMC) indicate that the ability of CRA 1, 2 to form supramolecular aggregates like micelles or hybrid micelles with SAA 3, 4 only weakly depends on the constitution of CRA functional groups. In the case of the hybrid micelles, when CMC are defined by the nature of surfactants 3 or 4, the methyl and methylene groups of the hydrophobic fragments (CRA 1, 2) were found to interact with the hydroxy groups of SAA 3 and ethylene oxide moieties of SAA 4.     

Generation of narrowly directed X-rays under optical pumping in synthetic opal matrices

Generation of narrowly directed X-rays in synthetic opal matrices upon pulsed laser excitation was detected. It was experimentally shown that this phenomenon occurs simultaneously with stimulated globular light scattering (SGLS) and the photon flame effect (PFE). Possible mechanisms of this effect were considered.     

Hydrolysis of bis(4-nitrophenyl) ethyl phosphate in micellar solutions of dicationic surfactants

The effect of dicationic surfactants on the hydrolysis of bis(4-nitrophenyl) ethyl phosphate in a borate buffer is studied. The presence of long-chain surfactants results in a significant (up to 50-fold) increase in the observed rate constant (k _obs) of the process. The catalytic effect of micelles increases with increasing alkyl chain length due to the strengthening of binding of the reagents by micelles. The presence of two cationic centers in the surfactant molecule enhances the catalytic properties of micelles. The dependence ofk _obs of hydrolysis of the substrate on the borate buffer concentration is studied. Alkaline hydrolysis is more sensitive to the added surfactant than the reaction involving borate ions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1576–1580, September, 1994.     

Inhibition of Alkaline Hydrolysis of Ethyl p-Nitrophenyl (Chloromethyl)phosphonate in the System Cationic Surfactant-Water-Electrolyte

The rate of alkaline hydrolysis of ethyl p-nitrophenyl (chloromethyl)phosphonate in micellar solutions of cationic surfactants decreases with increasing concentration of chloride, bromide, and salicylate ions. In the presence of electrolytes, the critical micell concentration of surfactants and the surface potential of micelles also decrease.     

Dicaffeolyquinic acids from Helichrysum italicum and Achillea cartilaginea

The quinic acid caffeates of the flowers ofHelichrysum italicum and the herbage ofAchillea cartilaginea have been studied with the use of HPLC,¹³H NMR spectroscopy, and chemical transformations.All-Union Research Institute of Medicinal Plants Scientific-Production Association, Moscow. Translated from Bioorganicheskaya Khimiya, No. 1, pp. 50–55, January–February, 1992.     

The catalytic effect of the cationic surfactant-polyethylene imine-water system in the hydrolysis ofO-alkylO-p-nitrophenyl chloromethylphosphonates

The kinetics of the hydrolysis ofO-alkylO-p-nitrophenyl chloromethylphosphonates in the cationic surfactant—polyethylene imine—water system was studied. The catalytic effects of the nature of the surfactant and substrate and the surfactant—polyethylene imine ratio were found. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1510–1514, September, 2000.