Synthesis and Luminescence of Europium-Containing Compositions Based on Yttrium Oxide and Oxyfluorides

By heating the products isolated from an ethyl acetate medium, luminescent europium-containing compositions based on yttrium oxyfluorides and oxide have been synthesized. The concentration of Eu³⁺ ions in the compositions was from 0.10 to 10 at % of the yttrium content. It has been shown that the (Eu_хY_1–х)_nO_n–1F_{n + 2}, (Eu_хY_1–х)OF, (Eu_хY_1–х)₂O₃, and (Eu_хY_1–х)5O₄F₇ phases are formed during the synthesis. The luminescence of the compositions is related to the ⁵D₀ → ⁷F_j electron transitions of Eu³⁺ ions. It depends on the synthesis conditions, the type of matrix, the position of the Eu³⁺ ions in the crystal lattice, the excitation wavelength, and other factors.     

Use of (NH4)4[Ni(OH)6Mo6O18]·nH2O heteropoly compound in fabrication of sulfide catalysts for hydropurification of diesel fractions

NiMo(S)/γ-Al₂O₃ hydropurification catalysts were synthesized using as a precursor the active sulfide phase of a heteropoly compound with Anderson structure, ammonium 6-molybdonickelate, and, for comparison, ammonium paramolybdate. The heteropoly compound synthesized was identified using X-ray phase analysis and IR spectroscopy and its thermal stability was analyzed with DTA. The hydrodesulfurizing and hydrogenating activity of catalysts synthesized from ammonium 6-molybdonickelate was examined in hydropurification of two diesel fractions with different contents of polycyclic aromatic hydrocarbons and close contents of sulfur. Original Russian Text ? P.A. Nikul’shin, N.N. Tomina, Yu.V. Eremina, A.A. Pimerzin, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 1, pp. 86–93.     

Influence of the composition of compositions based on organic compounds and chelate complexes of aluminun and yridium on their electroluminescent properties

The effect of the composition of electroluminescent compositions based on PEDOT, TPD, Alq₃, and Ir(PPy)₃, the structure of the cathode (Al, CaMg/Ag, Al/Ag), and the possibility of forming of emitting layers (thermovacuum deposition and centrifugation) on their current-voltage, voltage-brightness, and spectral characteristics has been studied. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 45, No. 1, pp. 54–58, January–February, 2009.     

Simulation of a defect region in KDP crystals doped with divalent iron ions. Comparison of defects induced by di-and trivalent metals

The crystal structure of Fe^II-doped KDP crystals was simulated with the use of specially developed partly covalent potentials. Different variants of introduction of impurity into the structure were analyzed. The M1 position was found to be more favorable for both isolated divalent and trivalent metal ions. Upon optimization, the coordinates of the Fe^II ion are (0.25, 0.44, 0.125). The Fe^II ions can aggregate to form “clusters” energetically more favorable than isolated defects. It seems that Fe^III ions cannot form aggregates.     

Comparative characterization of defects formed by di-and trivalent metal dopants in KDP crystals and the structural mechanism of influence of impurities on face morphology

The structure of KDP crystals doped with trivalent (Al³⁺, Fe³⁺, Mn³⁺, V³⁺, and La³⁺) and divalent (Ni²⁺, Co²⁺, Fe²⁺, Mn²⁺, Ca²⁺, Sr²⁺, and Ba²⁺) cations was simulated by minimizing the energy of atomic interactions. Three types of defects were revealed: isolated defect centers formed by M ³⁺ and Ni²⁺ ions, cluster chain centers formed by M ²⁺ ions with ionic radii exceeding 0.9 Å, and complex centers formed via the replacement of potassium ions by large Ba²⁺ dopants with the simultaneous replacement of some of the phosphorus atoms by silicon ones. The corresponding energies of defect formation are calculated. The surface morphology of the crystal faces is studied. The changes in morphology in the presence of M ³⁺ dopants are caused by their adsorption, whereas for M ²⁺ dopants, these changes are caused mainly by their incorporation into the crystal structure.     

Photo-and electroluminescence of organic molecular compositions on the basis of Alq<Subscript>3</Subscript>, TPD,and PVK

The solvents for producing qualitative electroluminescencing films are chosen on the basis of investigation into spectral-luminescent properties of aluminium tris-(8-oxyquinolinate) and N,N′-bis(3-methyl phenyl)-N,N′-diphenyl benzidine in chlorinated solvents (chloroform, dichloroethane, tetrachloroethane) and polyvinylcarbazole films produced from these solvents. The conditions for formation of anode/polymer film/cathode structures with the properties necessary for measuring voltage-current and voltage-luminance characteristics are worked through. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 89–95, May, 2008.     

Complexes of Cu(I) and Pd(II) with (+)-camphor and (–)-cavrone thiosemicarbazones: Synthesis,structure, and cytotoxicity of the Pd(II) complex

CuLCl, CuL¹Cl, PdLCl₂, and PdL¹Cl₂ complexes [L and L¹ being (+)-camphor and (–)-carvone thiosemicarbazones, respectively] have been synthesized. The structure of binuclear [Pd₂L²²Cl₄] complex has been determined by means of X-ray diffraction. The L² ligand (dehydrogenated (–)-carvone thiosemicarbazone) is coordinated via the bridging S atom to two Pd atoms. The complexes of Cu(I) and Pd(II) presumably have polynuclear and binuclear structure, respectively. These facts are in good agreement with IR and NMR spectroscopy as well as mass spectrometry data which indicate the coordination of L and L¹ ligands via the S atom. The influence of L¹ and PdL¹Cl₂ on viability of the Hep2 cell line has been studied. The PdL¹Cl₂ complex is more cytotoxic than L¹ ligand.