NMR determination of enantiomeric composition of 1-substituted 3-amino-1,2-dicarba-closo-dodecaboranes using Eu(hfc)3

Experimental conditions for determination of enantiomeric composition of 1-substituted 3-aminocarboranes by ¹H and ¹³C NMR spectroscopy using chiral shift reagent Eu(hfc)₃ have been found.     

Components of plants of the family Empetraceae. II. Flavonoids of Empetrum nigrum

Tomsk Medical Institute. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 875–876, November–December, 1988.     

Kinetics of electrochromic process in thin films of cathodically deposited nickel hydroxide

Ni(OH)₂ films have been obtained by cathodic deposition from 1 M Ni(NO₃)₂ on a glass with a current-conducting SnO₂ layer. The films have a porous structure and consist of chaotically joined formations of 100–150 nm in size. They contain a considerable amount of adsorbed water, because of which their refraction index was n?=?~1.5, whereas for crystalline nickel hydroxide, it was n?=?2.37. It has been shown that in the course of discoloration of films through a shift of their potential towards more negative values, an electric field is formed in the bulk of film, which accelerates the entry of cations into it (protons as [H₃O]⁺) from the electrolyte and electrons from ohmic contact. In this case, the initial dependence i(t), where i?~?t ^?1/4, is bound up with gradual increase in proton surface concentration. It is proposed to determine separately the dependence of the effective codiffusion coefficient of charge carriers (protons and electrons) on decoloration potential by the analysis of plots of current, injected charge, and luminous transmittance of films against time. This procedure involves a series of periodic stops of potential during the recording of current–potential curves for an electrochromic electrode and allows one to monitor the ratio of the film forms NiOOH and Ni(OH)₂ in the course of film reduction.     

Modification of chemically and physically obtained Fe3O4 magnetic nanoparticles with l-Lys for cell labeling

Russian Chemical Bulletin - Peculiar features of the modification of Fe3O4 magnetic nanoparticles (MNPs) obtained by co-precipitation from solutions of FeII and FeIII salts (10-nm MNPs) and by the...     

Synthesis and antiherpetic activity of novel purine conjugates with 7,8-difluoro-3-methyl-3,4-dihydro-2H-1,4-benzoxazine

Chemistry of Heterocyclic Compounds - A method for the synthesis of novel purine conjugates with 7,8-difluoro-3-methyl-3,4-dihydro-2H-1,4-benzoxazine containing fragments of ω-amino acids with...     

Novel purine conjugates with N-heterocycles: synthesis and anti-influenza activity

Chemistry of Heterocyclic Compounds - A number of novel amides were synthesized by coupling of 6-[(9H-purin-6-yl)amino]hexanoic acid to heterocyclic amines. The antiviral activity of the obtained...     

Acylative kinetic resolution of racemic amines using N-phthaloyl-(S)-amino acyl chlorides

A comparative study of the kinetic resolution of racemic 2-methyl-1,2,3,4-tetrahydroquinoline and 2,3-dihydro-3-methyl-4H-1,4-benzoxazine using N-phthaloyl-(S)-amino acyl chlorides as chiral acylating agents is described. Temperature and solvent effects on the stereochemical features have been examined. It has been found that N-phthaloyl-(S)-phenylalanyl and N-phthaloyl-(S)-2-phenylglycyl chlorides bearing aromatic substituents close to the stereogenic centre are more stereoselective acylating agents than N-phthaloyl-(S)-alanyl chloride. For the preparative kinetic resolution of racemic amines N-phthaloyl-(S)-phenylalanyl chloride proved to be the most appropriate chiral acylating agent.     

Theoretical investigation of the adsorption and diffusion of hydrogen on the surface and in the bulk of the intermetallic compound Mg2Ni

The intermetallic compound Mg₂Ni as a potential material for hydrogen storage has been investigated theoretically. The sorption and diffusion of a hydrogen atom in the bulk and on the surface of this material, as well as the step-by-step process of dissociative chemisorption of a H₂ molecule on the surface, have been considered. The dependence of the sorption energy of atomic hydrogen on the structural characteristics of the intermetallic compound Mg₂Ni has been analyzed.