Mechanicochemical interaction of plant proanthocyanidins with drugs

The possibility has been studied of regulating the solubility properties of deoxypeganine by binding it with plant proanthocyanidins (katatsin, kavergal, yantapsin).Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 226–228, March-April, 1995. Original article submitted April 14, 1994.     

Kinetics of Anodic Dissolution of Lithium out of Li x C6 Electrodes in Nonaqueous Lithium Perchlorate Solutions

Kinetics of processes occurring during anodic dissolution of Li _x C₆ electrodes formed in structures of carbonized fiber and cloth (CC) in solutions of lithium perchlorate in a mixture of propylene carbonate and dimethoxyethane is studied. It is shown that the Li _x C₆ (CC) electrodes have an approximately three times greater intercalation capacity, which is caused by specific features of the structure of CC. Values of the initial concentration of lithium defects in the structure of a surface layer of the CC matrix and the diffusion coefficients for lithium in the temperature range 293–323 K are calculated.     

Synthesis and Luminescence Characteristics of LaF<Subscript>3</Subscript>:Yb:Er Powders Produced by Coprecipitation from Aqueous Solutions

Hydrated lanthanum fluoride powders, both undoped, and doped with erbium and ytterbium fluorides (to a total content of 6–28 mol %), of the general formula RF₃ · nH₂O (n = 0.30 ± 0.01), crystallizing in the hexagonal system, were obtained by coprecipitation from aqueous solutions of the corresponding nitrates by the interaction with hydrofluoric acid. The dehydration is completed at 380°C. At 600°C, the concentrated solid solution decomposes to precipitate a phase with the structure of orthorhombic YF₃. The efficiency of the upconversion luminescence of the powders, excited at a wavelength of 974 nm, is low.     

Preparation and physicochemical properties of polymeric complexes of methyl benzimidazol-2-ylcarbamate with apple pectin

Polymeric complexes have been obtained by the combined mechanical treatment of enzyme-treated apple pectin and methyl benzimidazol-2 -ylcarbamate, and their physicochemical properties have been studied.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 896–900, November-December, 1995. Original article submitted May 11, 1995.     

Effect of the carbon material nature on cathodic intercalation of lithium

Kinetics of the formation of a Li_xC₆ anode are studied. The anode is formed by a cathodically intercalating lithium into such carbon materials as spectral graphite, carbonized fiber, and carbonized cloth of the Elur brand, in LiClO₄ solutions in a mixture of propylene carbonate and dimethoxyethane. Stable phases of Li_xC₆ form at potentials of-3.05 to -3.25 V relative to a non-aqueous Ag/AgCl electrode. A prolonged cathodic polarization makes lithium diffuse deeper into the electrode, the process being accompanied by a deeper lithiation of carbon materials. In the case of spectral graphite, compounds C_xLiClO₄ and C_xClO₄ form alongside Li_xC₆.     

Electrochemical Intercalation of Lithium into Graphite in Acetonitrile Solutions: The Effect of the Anion Nature

Effect of the anion nature on the cathodic intercalation of lithium into graphite is studied. The duration of a discharge process and the capacity of Li _x C₆ electrodes increase in the row Cl^– HSO₄ ^– < ClO₄ ^– < SCN^–. The highest negative potential of an Li _x C₆ electrode is reached when lithiating in an LiSCN non-aqueous solution. X-ray diffraction and microstructure analyses confirm the presence in the electrode's upper layers of predominantly layered compounds Li _x C₆A _y , where A is anion. In deep layers, the principal intercalation product is Li _x C₆.