38 research outputs found
Synthesis and properties of the heterospin (S1 = S2 = 1/2) radical-ion salt bis(mesitylene)molybdenum(I) [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazolidyl
The authors are grateful to the Presidium of the Russian Academy of Sciences (Project 8.14), the Royal Society (RS International Joint Project 2010/R3), the Leverhulme Trust (Project IN-2012-094), the Siberian Branch of the Russian Academy of Sciences (Project 13), the Ministry of Education and Science of the Russian Federation (Project of Joint Laboratories of Siberian Branch of the Russian Academy of Sciences and National Research Universities), and the Russian Foundation for Basic Research (Projects 13-03-00072 and 15-03-03242) for financial support of various parts of this work. N.A.S. thanks the Council for Grants of the President of Russian Federation for postdoctoral scholarship (grant MK-4411.2015.3). B.E.B. is grateful for an EaStCHEM Hirst Academic Fellowship. A.V.Z. thanks the Foundation named after D. I. Mendeleev, Tomsk State University, for support of his work.Low-temperature interaction of [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole (1) with MoMes2 (Mes = mesitylene / 1,3,5-trimethylbenzene) in tetrahydrofuran gave the heterospin (S1 = S2 = 1/2) radical-ion salt [MoMes2]+[1]– (2) whose structure was confirmed by single-crystal X-ray diffraction (XRD). The structure revealed alternating layers of the cations and anions with the Mes ligands perpendicular, and the anions tilted by 45°, to the layer plane. At 300 K the effective magnetic moment of 2 is equal to 2.40 μB (theoretically expected 2.45 μB) and monotonically decreases with lowering of the temperature. In the temperature range 2−300 K, the molar magnetic susceptibility of 2 is well-described by the Curie-Weiss law with parameters C and θ equal to 0.78 cm3⋅K⋅mol–1 and −31.2 K, respectively. Overall, the magnetic behavior of 2 is similar to that of [CrTol2]+[1]– and [CrCp*2]+[1]–, i.e. changing the cation [MAr2]+ 3d atom M = Cr (Z = 24) with weak spin-orbit coupling (SOC) to a 4d atom M = Mo (Z = 42) with stronger SOC does not affect macroscopic magnetic properties of the salts. For the XRD structure of salt 2, parameters of the Heisenberg spin-Hamiltonian were calculated using the broken-symmetry DFT and CASSCF approaches, and the complex 3D magnetic structure with both the ferromagnetic (FM) and antiferromagnetic (AF) exchange interactions was revealed with the latter as dominating. Salt 2 is thermally unstable and slowly loses the Mes ligands upon storage at ambient temperature. Under the same reaction conditions, interaction of 1 with MoTol2 (Tol = toluene) proceeded with partial loss of the Tol ligands to afford diamagnetic product.PostprintPostprintPeer reviewe
Electrical characteristics of thin-film emitters with excitation of electroluminescence by an ac voltage
Salix ledebouriana forma fastigiata (Salicaceae), a new form.
A new form, Salix ledebouriana f. fastigiata I. V. Belyaeva, V. V. Byalt, O. V. Epanch. et Firsov, is described and its characteristics in cultivation in Yekaterinburg and St. Petersburg are given
FONESYS : The Forum & Network of SYStem Thermal-Hydraulic Codes in Nuclear Reactor Thermal-Hydraulics
tThe purpose of this article is to present briefly the project called Forum & Network of System Thermal-Hydraulics Codes in Nuclear Reactor Thermal-Hydraulics (FONESYS), its participants, the motivation forthe project, its main targets and working modalities.System Thermal-Hydraulics (SYS-TH) codes, also as part of the Best Estimate Plus Uncertainty (BEPU)approaches, are expected to achieve a more-and-more relevant role in nuclear reactor technology, safetyand design. Namely, the number of code-users can easily be predicted to increase in the countries wherenuclear technology is exploited. Thus, the idea of establishing a forum and a network among the codedevelopers and with possible extension to code users has started to have major importance and value.In this framework the FONESYS initiative has been created. The main targets of FONESYS are:•To promote the use of SYS-TH Codes and the application of the BEPU approaches.•To establish acceptable and recognized procedures and thresholds for Verification and Validation (V&V).•To create a common ground for discussing envisaged improvements in various areas, including user-interface, and the connection with other numerical tools, including Computational Fluid Dynamics(CFD) Code