New method for synthesis of lamellar compounds of graphite with lithium

Conclusions The stirred reaction of graphite with molten lithium gave compounds of composition C₆Li, C₁₂Li, and C₁₈Li, for which the identity periods and thicknesses of the filled layers were determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 671–672, March, 1979.     

Electrophosphorescence of aromatic polyimides doped with platinum porphyrins

The mechanism of electroluminescence in polymeric thin-layer devices based on aromatic polyimides and various molecular complexes of Pt porphyrins as heavy-atom-containing luminophores was studied. On the basis of spectral and electron-hole transport properties of aromatic polyimides and Pt porphyrins, as well as the current concepts adopted in polymer photonics, the processes of singlet-singlet and triplet-triplet energy transfer in the examined single-layer systems aromatic PI-Pt porphyrin with a high electrophosphorescence quantum yield exceeding 2% are discussed.     

A Simple Method for Determining the Enthalpy of Specific Solute-Solvent Interaction

An equation correlating a parameter that described the enthalpy of nonspecific solvation of nonelectrolytes with a quantity characterizing intermolecular solute-solvent interaction was found. A simple and versatile method based on this equation was suggested for calculating the enthalpy of nonspecific solvation and the enthalpy of specific solute-solvent interaction.     

Low-temperature heat capacity of dysprosium diboride

A novel microcalorimeter based on a miniature liquid-in-glass thermometer is described. Heat is transduced into an optical, rather than electrical, signal, facilitating a future array format. The instrument performs batch analysis (drop mixing) with a 2 μL sample volume. Energy changes of 4 μJ produced by a dilution of sulfuric acid are resolvable. The effect of evaporation, and measures taken to limit it, are discussed.     

Crystal structure of [Co(NH3)5NO2]C2O4. Analysis of specific contacts and structural effects hindering inner-spheric nitro-nitrito isomerization

The structure of [Co(NH₃)₅NO₂]C₂O₄ is solved and refined (space group Immm, a=7.428(2), b=9.790(3), c=6.568(1) Å, V=477.6(2) ų, Z=2; R₁=0.0177, wR₂=0.0279 for F²>4σ(F²); R₁=0.1177, wR₂=0.0643 for all data; residual electron density from 0.125 to ?0.140 e/ų). Specific contacts in the structure are analyzed. Crystal chemical interpretation is suggested to explain the occurrence of photodecomposition rather than photochemical bond isomerization under the action of light in cobalt(III) nitropentammoniate oxalate crystals, in contrast to all previously investigated cobalt(III) nitropentammoniates.     

New approach to the nonparametric determination of the internal rotation potential from electron diffraction data. Reinvestigation ofm-bromonitrobenzene

A numerical algorithm for the nonparametric determination of the internal rotation potential from electron diffraction data using Tikhonov's regularization method is described. The range of admissible values of the regularization parameter is estimated using Hamilton's statistical criterion. m-Bromonitrobenzene was reinvestigated using this approach. It was found that the form of the potential may be reliably established only in the region of the minimum corresponding to the planar conformation of the molecule. Fourier series approximation of the experimental values of the potential in the region of the minimum gives the rotation barrier of 4.6–5.4 kcal/mole. The following basic geometrical parameters have been obtained (r_a in Å, ∠_α in deg, the error equals triple standard deviation): r(C?C)_ave=1.399(3), r(C?N)=1.459(16), 1.459(16), r(N=O)=1.244(3), r(C?Br)=1.884(6), r(C?H)=1.099(20), ∠CC_NC=123.9(1.4), ∠C_NCCBr=116.8(1.5), ∠C_NCC=116.6(1.9), ∠CNO=118.8(0.8). The results are compared with the data for the related compounds.     

Use of1H and13C NMR spectroscopy to determine the stereochemistry of 1 - methyl- δ4-octalin- 1,2-dicarboxylic acids and their derivatives

Conclusions The combined use of the¹H and¹³C NMR spectra makes it possible to unequivocally assign 1-methyl-⁴-octalin-l,2-dicarboxylic acids and their derivatives to the proper steric series.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1429–1431, June, 1977.     

Nonreciprocal effects in light reflection by a moving medium

Nonreciprocal effects in light reflection by a medium moving along an interface are considered in a weakly relativistic approximation. It is found that nonreciprocal effects are anomalously large in the vicinity of the Brewster and the total-internal-reflection (TIR) angles when light is reflected by transparent moving media. These effects exceed considerably (by several orders of magnitude) the ratio of the velocity of the reflecting medium to the velocity of light and can be proportional to rather than to under certain conditions. We show new possibilities for the creation a method for investigation of the structure of nonuniform flows with a very small spatial scale (less than one millimeter). This method is based on measurement of amplitude and phase nonreciprocities in light reflection by these flows.Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 11, pp. 1146–1157, November, 1995.