Synthesis of primary phosphines from phosphine and arylethylenes

Russian Chemical Bulletin -     

Mass-spectrometric study of tetrafluorohydrazine and the products resulting from its breakdown under electron impact

Conclusions Electron-impact methods have been used to study positive (NF⁺, NF₂ ⁺, N₂F₂ ⁺) and negative (F^–, F₂ ^–, N₂F^–, NF₂ ^–) ion formation in the mass spectra of tetrafluorohydrazine and its decomposition products.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1306–1311, June, 1978.The authors would like to thank V. Ya. Rosolovskii for a discussion of the results obtained in this work.     

A Femtosecond Pulse Train with a Selectable Carrier–Envelope Offset Phase

Optics and Spectroscopy - A method and a scheme of obtaining a femtosecond pulse train without frequency comb offset and selectable carrier–envelope offset phase are proposed.     

Applying an improved phonon confinement model to the analysis of Raman spectra of germanium nanocrystals

The improved phonon confinement model developed previously [11] is applied for definition of germanium nanocrystal sizes from the analysis of its Raman scattering spectra. The calculations based on the model allow determining the sizes of germanium nanocrystals more precisely from the analysis of their Raman spectra. In some cases, the comparative analysis of Raman data and electron microscopy data is carried out, and good agreement is observed.     

Fluctuations of g factors in metal nanoparticles: effects of electron-electron interaction and spin-orbit scattering

We investigate the combined effect of spin-orbit scattering and electron-electron interactions on the probability distribution of g factors of metal nanoparticles. Using random matrix theory, we find that even a relatively small interaction strength significantly increases g-factor fluctuations for not-too-strong spin-orbit scattering (ratio of spin-orbit rate and single-electron level spacing 1/tau(so)delta < or near 1), and leads to the possibility to observe g factors larger than 2.     

Bound on anisotropy in itinerant ferromagnets from random impurities

We calculate the anisotropy energy of a single-domain ferromagnetic particle in which the only source of anisotropy is the presence of nonmagnetic impurities. Such anisotropy has easy-axis and easy-plane contributions, with random orientations of the axes. Typically the anisotropy energy is of order N1/2plankv/tau(so), where N is the number of electrons in the ferromagnetic particle and tau(so) is the spin-orbit time.     

Selective dissociation of SF6 molecules in a two-frequency infrared laser field

The dissociation of SF₆ in the field of two infrared frequencies is studied. It is shown that the selectivity of dissociation is increased compared to the single frequency dissociation case. The dispersion characteristics of the vibrational quasicontinuum have been obtained. A theoretical model of the processes is discussed.     

Thermodynamic functions and the enthalpies of formation of gaseous VOX<Subscript>3</Subscript> vanadium oxotrihalides

A critical analysis of experimental and theoretical data on the structure and vibrational frequencies of gaseous VOX₃ vanadium oxotrihalides is performed. The values of molecular constants are selected and the thermodynamic functions are calculated within a “rigid rotator–harmonic oscillator” approximation. Equations that approximate a temperature dependence of heat capacity within the temperature range of 298.15–3000 K are obtained. Analysis of the available experimental data allows the enthalpy of formation to be determined for gaseous VOCl₃ molecules. The enthalpies of formation for VOF₃, VOBr₃, and VOI₃ molecules are determined for the first time using this value and quantum-chemical calculations of energy of exchange reactions involving VOCl₃. The obtained results are added to the database of the IVTANTERMO software.     

Coherent states and path integrals for model hamiltonians in quantum optics

A brief review of applications of the coherent states (CSes) in quantum optics is given. The CS representation of path integrals in the semi-classical approximation leads to the classical dynamics of CS parameters. Calculations of squeezing in the model of spontaneous parametric scattering are performed and the chaos in the collective dynamics of three-level atoms interacting with resonant photon modes is studied.