Diastereotopic splitting in the 13C NMR spectra of sulfur homofullerenes and methanofullerenes with chiral fragments

Using gauge‐invariant atomic orbital PBE/3ζ quantum chemistry approach, ¹³C NMR chemical shifts and diastereotopic splittings of sp² fullerenyl carbons of a number of sulfur homofullerenes and methanofullerenes have been predicted and discussed. An anisochrony of fullerene carbons is caused by a chiral center of attached moieties. Clearly distinguishable diastereotopic pairs (from 8 to 11) of fullerenyl carbons of homofullerenes were observed. Unambiguous assignments of ¹³C NMR chemical shifts were performed, and diastereotopic splittings of methanofullerenes were observed for α, β and γ to a functionalization site. Copyright © 2013 John Wiley & Sons, Ltd.     

Effective synthesis of <Emphasis Type="Italic">N</Emphasis>-substituted 1,3,5-dithiazinanes by reactions of <Emphasis Type="Italic">N</Emphasis>-methyl-1,3,5-dithiazinane and 1,3,5-trithiane with aromatic amines

A novel procedure has been developed for selective synthesis of N-aryl-1,3,5-dithiazinanes, 1,2,6,7-tetrahydro-3,5,1,7-benzodithiadiazonine, and 6,7-dihydro-1,3,5,7-benzotrithiazonine by reactions of aniline derivatives with N-methyl-1,3,5-dithiazinane or 1,3,5-trithiane in the presence of transition and rare earth metal salts and complexes.     

A quantum chemical study of self-association of HAlBu 2i and ClAlBu 2i

The self-association of di-iso-butylaluminum hydride and di-iso-butylaluminum chloride is studied at the level of density functional theory and second order M?ller-Plesset perturbation theory. Thermodynamic parameters of the monomeric, dimeric, trimeric, and tetrameric forms of HAlBu₂ ⁱ and ClAlBu₂ ⁱ in a range of 203 K to 373 K are calculated. The energy of solvation is taken into account by the COSMO polarized continuum model. Based on the obtained results the equilibrium concentrations of the associated forms of organoaluminum compounds (OACs) are calculated, which agree with the experimental data. So, at room temperature the dimeric or trimeric forms of OACs are dominant in the gas phase and non-polar solvents; the tetrameric form is present, while the concentration of the monomeric form is negligibly low and decreases with decreasing temperature or diluting.     

Synthesis of bicyclo[2.2.1]hept-5-enyl methyl esters of haloacetic acids

Synthesis of norbornenyl methyl esters of a number of haloacetic acids via [4+2] cycloaddition of cyclopentadiene to allyl esters of these acids was examined. The yield and isomer composition of the synthesized compounds were examined in relation to the reaction conditions, and the best conditions for their preparation were found.     

Two-dimensional electron gas in a strong magnetic field. I

We obtain expressions for the thermodynamic potential, concentration, and magnetic moment of an ideal two-dimensional electron gas in a strong (quantizing the motion) magnetic field at low temperatures. The results are used to explain the integer quantum Hall effect.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 101–106, January, 1990.     

Synthesis of functionally substituted methanofullerenes and study of their tribological properties

Possibility of synthesizing functionally substituted methanofullerenes by cycloaddition of diazo derivatives of methionine and threonine to C₆₀ fullerene in the presence of a three-component catalytic system Pd(acac)₂-PPh₃-Et₃Al was examined. Tribological characteristics of the resulting compound as an additive to an industrial oil were studied.     

Electron in the Aharonov-Bohm potential and in the Coulomb field in 2+1 dimensions

We obtain exact solutions of the Dirac equation in 2+1 dimensions and the electron energy spectrum in the superposition of the Aharonov-Bohm and Coulomb potentials, which are used to study the Aharonov-Bohm effect for states with continuous and discrete energy spectra. We represent the total scattering amplitude as the sum of amplitudes of scattering by the Aharonov-Bohm and Coulomb potentials. We show that the gauge-invariant phase of the wave function or the energy of the electron bound state can be observed. We obtain a formula for the scattering cross section of spin-polarized electrons scattered by the Aharonov-Bohm potential. We discuss the problem of the appearance of a bound state if the interaction between the electron spin and the magnetic field is taken into account in the form of the two-dimensional Dirac delta function. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 149, No. 3, pp. 502–517, December, 2006. An erratum to this article is available at .     

Spin effects in processes with the participation of high-energy particles in a magnetic field

The fundamental characteristics of electromagnetic processes are considered in the presence of an external magnetic field in which electron (positron) self-polarization occurs.From material of a report to the All-Union Conference on Investigation of Spin Phenomena in High-Energy Physics (Protvino, November, 1982).Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 12–16, July, 1984.