Solvent Effect on the Activation Volume of the Diels-Alder Reaction Between Tetracyanoethylene and trans,trans-1,4-Diphenyl-1,3-butadiene

The effect of increased hydrostatic pressure on the rate of the Diels-Alder reaction of tetracyanoethylene with trans,trans-1,4-diphenyl-1,3-butadiene at 25°C was studied to estimate the reaction volume and to show that it considerably varies with -donor properties of the medium.     

Hydrogen atoms in impurity-helium solids

Electron spin resonance (ESR) is employed to study atomic impurities (H and D) stabilized in impurity-helium (Im-He) solids at 1.35-1.5 K. The kinetics of the low temperature tunneling exchange reactions (D+H2-->H+HD, D+HD-->H+D2) are investigated in Im-He samples containing several different mixtures of hydrogen and deuterium impurities. The ESR line structures help determine the local environment of atoms trapped in Im-He solids. High concentrations of atomic hydrogen stored in Im-He solids may ultimately find applications in energy storage, matrix-isolation spectroscopy, and studies of different quantum statistical effects.     

Calculation of photoemission characteristics of cubic K3Sb

A three-step model of photoelectron emission is used to calculate the quantum efficiency and the energy distribution functions of emitted electrons with allowance for the scattering of the excited electrons leading to the production of electron-hole pairs. The calculated quantum efficiency is compared with experimental data in the visible part of the spectrum. The correlation between the structure of the photoemission characteristics and the density of the electron states is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 20–25, October, 1980.     

Optical properties of cubic K3Sb

A number of optical characteristics of the crystal K₃Sb of cubic structure (the complex dielectric permeability function, the density of electron states, the refractive and absorptive indices, the optical density of the material) are computed on the basis of the electron energy spectrum calculated by the pseudopotential method taking account of nonlocality and spin-orbital interaction. Direct and indirect transition models to describe the optical excitation of electrons are discussed. Theoretical and experimental curves are compared.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 33–39, February, 1979.