Production and properties of high purity TeO2− WO3−(La2O3, Bi2O3) and TeO2− ZnO−Na2O−Bi2O3 glasses

TeO₂–WO₃ (TW), TeO₂–WO₃–La₂O₃ (TWL), TeO₂–WO₃–La₂O₃–Bi₂O₃ (TWLB) and TeO₂–ZnO–Na₂O–Bi₂O₃ (TZNB) glasses were produced by high-purity oxide mixtures melting in platinum or gold crucible at 800 °C in the atmosphere of purified oxygen. The total content of Cu, Mn, Fe, Co and Ni impurities was not more than 0.1–0.5 ppm wt in the initial oxides and glasses. The stability of TZNB glasses to crystallization, characterized by (T_x ? T_g) value more than 150 °C, was demonstrated by DSC measurements at heating rate 10 K/min. In the case of La₂O₃-containing glasses the thermal effects of both crystallization and fusion of the crystallized phases were not observed. The hydroxyl groups absorption coefficients of pure tellurite glasses at the maximum of the absorption band (λ ~ 3 μm) were in the region of 0.012–0.001 cm^?1. The optical absorption losses, measured by the laser calorimetry method at λ = 1.56 and 1.97 μm, did not exceed 100 dB/km.     

Synthesis, properties, and crystal structure of barium 1-oxyethylidenediphosphonatohydroxogermanate(IV) polyhydrate Ba3[Ge(μ-OH)(μ-Oedph)]6 · 25H2O

The barium salt of 1-oxyethylidenediphosphonatohydroxogermanium acid Ba₃[Ge(μ-OH)(μ-Oedph)]₆ · 25H₂O (I) (H₄Oedph is 1-oxyethylidenediphosphonic acid) was synthesized and studied by X-ray diffraction. The complex was characterized by elemental analysis, thermogravimetry, and IR spectroscopy. The hexanuclear cyclic complex anions [Ge(μ-OH)(μ-Oedph)] ₆ ^6-t- ] cations, and water molecules of crystallization are the structural units of the crystal of I.     

Complexation between tungsten(VI) and citrate: The crystal and molecular structure of a dinuclear complex,Na6[W2O5(cit)2]·10H2O

The crystals of the title compound are monoclinic, space groupP2₁/c witha=9.014(1),b=9.8668(5)c=17.5000(3) Å,=91.50(1)°,V=1556(1) ų. The structure was determined by Patterson methods and refined by least squares toR=0.038 for 3829 observed reflections and 224 parameters. There are two tungsten dimers in the unit cell, each formed by a bridging oxygen lying on a center of symmetry. Each tungsten has five more coordination sites; two occupied by terminal oxygens and the remaining three by citrate oxygens. Waters of crystallization are distributed throughout the cell and together with various of the anion oxygens, make the sodium cations either five-or six-coordinate.     

Seven-coordinated chelate [Cd(SCZ)3·H2O](HTNR)2(H2O)2: Synthesis,crystal structure and energetic properties

To deepen the study on heptacoordinate transition metal coordination complexes, a novel seven-coordinated coordination compound [Cd(SCZ)₃·H₂O](HTNR)₂(H₂O)₂ (1, SCZ = semicarbazide, H₂TNR = styphnic acid) was synthesized and characterized by elemental analysis and FTIR spectroscopy. Single-crystal X-ray diffraction analysis revealed that 1 crystallizes in the triclinic space group P-1. The thermal decomposition mechanism of 1 was studied by differential scanning calorimetry (DSC). The non-isothermal kinetics parameters were calculated by the Kissinger's method and Ozawa-Doyle's method, respectively. Sensitivity tests revealed that 1 is insensitive to mechanical stimuli. The heat of combustion was measured by oxygen bomb calorimetry and the enthalpy of formation was calculated.     

Nanostructured crystals of fluorite phases Sr1 − x R x F2 + x (R are rare-earth elements) and their ordering. I. Crystal growth of Sr1 − x R x F2 + x (R = Y,La, Ce,Pr, Nd,Sm, Gd,Tb, Dy,Ho, Er,Tm, Yb,and Lu)

Crystallography Reports - Crystals of nonstoichiometric phases Sr1 − x R x F2 + x (R are 14 rare-earth elements) and the ordered phase Sr4Lu3F17 with a trigonally distorted fluorite lattice...