Redox properties and antiradical activity of humic acids under exposure to UV and visible light

Changes in the redox and antiradical properties of humic acids upon exposure to monochromatic UV light of an excilamp and polychromatic light of a helium lamp were studied.     

Conductivity increase effect in nanocomposite polymer gel electrolytes: manifestation in the IR spectra

Nanocomposite polymer electrolytes based on poly(ethylene glycol) diacrylate and 1 M LiBF₄ solution in γ-butyrolactone containing SiO₂ nanoparticles were studied by FT IR spectroscopy. Quantum chemical modeling of five different solvate complexes of ions composed of LiBF₄ with solvent molecules was carried out and their theoretical IR spectra were calculated. The compositions of the solvate complexes of LiBF₄ in the nanocomposite gel electrolyte were studied by comparing the experimental and theoretical IR spectra. It was concluded that the conductivity peak observed upon adding 2 wt.% SiO₂ is due to the appearance of mobile ions as a consequence of ionic dissociation on the surface of nanoparticles at their optimal configuration.

     

Reductive transformation of isoprenoid cyclosulfonates into linear homoallylic alcohols and amines

Conclusions Isoprene, myrcene, and ocimene sultones were converted into the corresponding linear homoallylic alcohols and amines via the stage of desulfonylation of the in situ generated allylsulfinic acids. A new synthesis of myrcenol and isogeraniol has been carried out.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1820–1823, August, 1985.     

Synthesis of 3-desmethylhexaprenol WT3C2OH

A six-step synthesis of 3-desmethylhexaprenol WT₃C₃OH was carried out in continuation of studies of the relationship between the structure of polyprenols and their biological properties.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 803–806, April, 1990.     

Synthesis and properties of photochromic 6-methacrylylaminobenzothiazolinospiropyrans

The reaction of 2-ethyl-6-aminobenzothiazole with methacrylyl chloride was used to synthesize the corresponding amide, which was then converted, without isolation, to 2-ethyl-3-methyl-6-methacrylylaminobenzothiazolium iodide. The reaction of the quaternary salt with nitro derivatives of salicylaldehyde leads to benzothiazolinospiropyrans containing a methacrylyl grouping. A copolymer of 3,3-dimethyl-6-methacrylylamino-6-nitrospiro-(benzothiazoline-2,2-[2H-1]benzopyran) with methyl methacrylate was obtained. The photochromic properties of the synthesized benzothiazolinospiropyrans were investigated.Communication VIII from the series Photochromism of Organic Substances. See [1] for communication VII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1639–1642, December, 1973.     

Cryochemical modification,activity, and toxicity of dioxidine

Dioxidine nanoparticles are prepared via cryochemical modification of the pharmacopoeial dioxidine substance. The form of the cryomodified dioxidine is characterized by data from ¹H NMR spectroscopy; X-ray diffraction analysis; such thermal analytical methods as TG and DSC; low-temperature argon adsorption; and transmission electron microscopy. It is shown that the cryomodified samples are synthesized in the form of dioxidine nanocrystals 50–300 nm in size, with a crystal structure differing from that of the initial pharmacopoeial substance. The prepared cryomodified dioxidine nanoparticles inhibit the growth of E. coli 52, S. aureus 144, M. cyaneum 98, and B. cereus 9 better than the initial pharmacopoeial substance, and have comparable chronic toxicity.     

Synthesis of 2-aminoethyl glycosides of chitooligosaccharides

Russian Chemical Bulletin - 2-Aminoethyl glycosides of chitotriose, chitopentaose, and chitoheptaose were synthesized. The successive extension of the oligosaccharide chain by two monosaccharide...     

An effect of sprinkling density on a value of active surface of irregular heat and mass transfer packing

The results of analysis of an influence of a sprinkling density in the packed columns were reported on a value of an active surface of irregular ring nozzles such as Raschig and Pall rings. Sizes of Raschig rings were 15, 25 and 50 mm; Pall rings, 50 mm. Values of fluid load was 10, 20, 30, 40 and 50 m³ m⁻² h⁻¹). The results of the analysis were presented in graph form.     

The evolution of two-frequency solitons in an optical fiber with a longitudinally nonuniform nonlinearity

The evolution of two-frequency solitons in an optical fiber, as well as the practically important special case of absence of the second-harmonic wave, in the presence of a longitudinal nonuniformity of the coefficients characterizing the propagation nonlinearity are considered. The solitons found for media with constant values of the nonlinearity coefficients are used as initial distributions for media with a periodic dependence of the nonlinearity coefficients on the longitudinal coordinate. Modulation of the coefficient of cubic or quadratic nonlinearity is shown to result in oscillations of the peak intensity of the solitons (in both their components if two-color solitons are considered). In the case of a weak modulation of the nonlinearity coefficients, oscillations of the peak intensity occur at the frequency coinciding with the frequency of modulation of the nonlinearity coefficients. Under the weak influence of a periodically modulated cubic nonlinearity, parameters of quadratic solitons also oscillate upon the propagation. Regions of stability of solitons in the space of the modulation parameters are established.