[(1S)-endo]-(−)-borneol-tethered oxazoline phosphite as a P,N-bidentate ligand in palladium-catalyzed enantioselective allylic amination

P,N-Bidentate oxazoline phosphite containing an acyclic phosphorus center with [(1S)-endo]-(−)-borneol fragments and its palladium chelate complex [Pd(η-C₃H₅)(η²-P,N)]BF₄ were synthesized for the first time. The use of this new ligand in Pd-catalyzed asymmetric amination of 1,3-diphenylpropenyl acetate with pyrrolidine afforded the product with 86% ee. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2106–2108, December, 2006.     

Determination of a Dose Absorbed in a Biological Sample under Mixed Gamma–Neutron Irradiation

Technical Physics - A method is proposed and results on determination of absorbed doses under mixed gamma–neutron irradiation of biological samples on a horizontal channel of the IR-8...     

Superconducting Multipole Wigglers for Generating Synchrotron Radiation at the Budker Institute of Nuclear Physics

Physics of Particles and Nuclei Letters - Superconducting multipole insertion devices (wigglers and undulators) used to generate synchrotron radiation significantly increase the photon flux,...     

Homoannular disubstituted ruthenocenes containing a trifluoromethyl(tetramethyl)cyclopentadienyl ligand

The reaction of the divalent ruthenium complexes [Cp^FRuCl]_n and [Cp^FRu(MeCN)₃]PF₆ with substituted pentafulvenes 1,2-(Me₂NCH)(CO₂Et)C₅H₃ and 1,3-(Me₂NCH)(CO₂Et)- C₅H₃ followed by hydrolysis affords new homoannular disubstituted ruthenocenes {1,2- (CO₂Et)(CHO)C₅H₃}RuCp^F and {1,3-(CO₂Et)(CHO)C₅H₃}RuCp^F (Cp^F = C₅Me₄CF₃), re- spectively.     

The Discrete Spectrum in the Spectral Gaps of Semibounded Operators with Non-sign-definite Perturbations

Given two self-adjoint operators A and V = V₊  − V₋ , we study the motion of the eigenvalues of the operator A(t) = A − tV as t increases. Let α > 0 and let λ be a regular point for A. We consider the quantities N₊ (V; λ, α), N₋ (V; λ, α), and N₀(V; λ, α) defined as the number of eigenvalues of the operator A(t) that pass point λ from the right to the left, from the left to the right, or change the direction of their motion exactly at point λ, respectively, as t increases from 0 to α > 0. We study asymptotic characteristics of these quantities as α → ∞. In the present paper, the results obtained previously [O. L. Safronov, Comm. Math. Phys.193 (1998), 233–243] are extended and given new applications to differential operators.     

Structural features of polymeric silicon glycerolate hydrogels

Structural features of polymeric silicon glycerolate hydrogels based on tetrafunctional silicon glycerolates were investigated using model process, namely, hydrolytic transformation of difunctional silicon glycerolates, by IR and ¹H NMR spectroscopy, elemental analysis, atomic emission spectrometry. The possibility of forming a polymer network containing Si—O—Si and Si—OCH₂CH(OH)CH₂O—Si fragments was demonstrated. The molecular weight of the sub-chains in the network was calculated using Flory—Rehner approach based on the mechanical properties of the swollen network of flexible polymeric chains.