Pathways for cyclizations of hydrazine-derived 2-(2-cyanovinyl)-3-oxo-cyclohex-1-ene enolates

The introduction of a hydrazine functionality into 2-(2-cyanovinyl)-3-oxo-cyclohex-1-ene enolates results in their spontaneous cyclizations with participation of the hydrazine moiety. Depending on the reaction conditions used, the hydrazine-derived enolates are transformed into derivatives of 1-arylpyridine-2-one-3-carbonitriles or pyrazoloquinolinones in a one-pot synthesis. They also react with anilines to give the corresponding N1-substituted pyridine-2-one-3-carboxamides. Product characterization was performed by means of spectroscopic and X-ray diffraction studies. In addition, for structure elucidation purposes, a counter synthesis of 1-arylaminopyridine-2-one-3-carboxamide was also carried out.     

The Siegel-Brauer theorem concerning parameters of algebraic number fields

An upper bound is obtained for the product of the number of classes of ideals and the regulator of algebraic number fields.Translated from Matematicheskie Zametki, Vol. 8, No. 2, pp. 259–263, August, 1970.     

Nanotechnology and chip level systems for pressure driven liquid chromatography and emerging analytical separation techniques: a review

Pressure driven liquid chromatography (LC) is a powerful and versatile separation technique particularly suitable for differentiating species present in extremely small quantities. This paper briefly reviews main historical trends and focuses on more recently developed technological approaches in miniaturization and on-chip integration of LC columns. The review emphasizes enabling technologies as well as main technological challenges specific to pressure driven separations and highlights emerging concepts that could ultimately overcome fundamental limitations of conventional LC columns.     

Method for Determining Formation Constants of the Intermolecular H-Bond from Data of IR Spectroscopy

Russian Physics Journal - An experimental method is proposed for determining the efficiency of forming intermolecular hydrogen bonds by determining the formation constant of the H-complex (K). The...     

Effect of polymer additives on magnetic modulation of the yield of products of recombination of triplet radical ion pairs in electron phototransfer between N,N-Dimethylaniline and pyrene. 2. Poly-N-tert-butylacrylamide in methanol

The effect of a magnetic field on the intensity of delayed fluorescence of pyrene excimers formed during evolution of pyrene — N,N-dimethylaniline radical ion pairs (RIP) in methanol containing glycerol or poly-N-tert-butylacrylamide was comparatively investigated by laser strobe fluorometry. Different methods of restricting the molecular mobility of the reagents cause different values of the magnetic effect with the same microviscosity measured with the spin probe orientational correlation time. This result contradicts the data obtained previously for mixtures with polyacrylamide and can be explained with the data on cross-linking of the polymer-containing solution. The viscosity of the microenvironment of the RIP partners is 10 times higher than the viscosity of the solvent. The presence of a maximum on the curve of the change in the magnetic effect in restriction of the molecular mobility was attributed to an increase in the lifetime of the radical pair and a change in the ratio of the relaxation rates and yield of radicals in bulk.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117334 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 2059–2065, September, 1992.