Effect of Barium Codoping on Superconductivity in SrxBi2Se3

JETP Letters - A structural reason for superconductivity in a Cu-, Sr-, or Nb-atom-doped Bi2Se3 topological insulator is still unclear. To understand this reason, a codoping approach has been...     

Condensation of [2-(α-carbinol)norbornadiene]cyclopentadienylrhodium complexes with CH acid compounds

Conclusions The reaction of the 2-(-carbinol)norbornadiene complexes of rhodium with aliphatic nitro compounds and other CH acids was discovered, which leads under mild conditions to condensation products.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 935–937, April, 1984.     

Specifics of radical polymerization of styrene and methyl methacrylate in the presence of ruthenium carborane complexes

The specifics of the radical polymerization of styrene and methyl methacrylate in the presence of ruthenium closo- and exo-nido-carborane complexes with phosphine and diphosphine ligands were investigated. It was shown that, depending on a coinitiator, the polymerization proceeds through the atom transfer radical mechanism or the reverse atom transfer radical mechanism to high conversions without gelation to yield macromolecules with a low polydispersity. The influence of the ligand environment, the oxidation state of ruthenium atoms in the carborane complexes, and the temperature conditions on the specific features of the polymer synthesis was established.     

Infrared spectroscopy of Bi2Te2Se

The infrared reflection and transmission spectra of Bi₂Te₂Se single crystals grown by the modified Bridgeman method have been studied in the spectral range of 30–10000 cm^?1 at temperatures of 5–300 K. The bandgap and its temperature dependence, optical function spectra, and concentration of free charge carriers in Bi₂Te₂Se have been determined.     

Complexation in a 5-acylpyrimidine-4-thione—aliphatic diamine—metal(II) chloride system (M = Ni or Co). The molecular structure of <Emphasis Type="Italic">fac</Emphasis>-tris(5-acetyl-2,4-dimethylpyrimidine-6-thiolato)cobalt(III)

The reactions of 5-acylpyrimidine-4-thiones with aliphatic diamines in the presence of Ni^II and Co^II salts were studied. New Ni^II and Co^III complexes with ligands of the pyrimidinethione series were synthesized. The results of the reactions of 5-acetyl-6-methyl-2-phenylpyrimidine-4-thione and 5-acetyl-2,6-dimethylpyrimidine-4-thione with ethylenediamine or 1,3-diaminopropane in the presence of NiCl₂· 6H₂O or CoCl₂·6H₂O depend on (1) the nature of the substituent at position 2 of the pyrimidine ring, (2) the length of the polymethylene bridge between the nitrogen atoms in the diamine molecule, (3) the nature of complex-forming metal, and (4) the pyrimidinethione: diamine ratio. The resulting complexes were studied by electrochemical methods. The mechanism of electrooxidation and electro-reduction of 5-acylpyrimidine-2-thiones and related nickel and cobalt complexes was proposed. The structures of the complexes were investigated by NMR, UV-Vis spectroscopy, and IR spectroscopy and mass spectrometry. The molecular structure of fac-tris(5-acetyl-2,4-dimethylpyrimidine-6-thiolato)cobalt(III) was established by X-ray diffraction. According to semiempirical quantum-chemical calculations by the PM3(tm) method, both the highest occupied and lowest unoccupied molecular orbitals in the molecules of the compounds under study have a π symmetry and are localized predominantly on the ligand fragments. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2666–2678, December, 2005.