Über Verbindungen des Typs Ba2BIIIOsVO6

Compounds of Type Ba₂B^IIIOs^VO₆ The black perovskites of type Ba₂B^IIIOs^VO₆ crystallize cubic (B^III ? Pr, Nd, Sm—Lu, Y) and rhombohedral (B^III ? La) respectively; the cell volumina decrease linearily with (r_BIII)³. Intensity calculations on powder data for Ba₂YOsO₆ (space group Fm3m—O) and Ba₂LaOsO₆ (space group R3m—D) gave the intensity related R′ values of 4.6% and 5.0% respectively. The results of the vibrational spectroscopic investigations are reported in common with the bond orders, M? O distances and mean amplitudes and compared with the corresponding values of the series Ba₂B^IIIIr^VO₆ and Ba₂B^IIIRu^VO₆.     

Über Das System Ba2Sm0,67U1−xWxO6

On the System Ba₂Sm _0.67U_1?xW_xO₆ The ordered perovskites Ba₂Sm_0.67UO₆ and Ba₂Sm_0.67 WO₆ are forming a complete serie of solid solutions with 4 formula units Ba₂Sm_0.67U_1?xW_xO₆ in the unit cell. By diffuse reflectance and i.r.-spectroscopic measurements the relations between color and constitution are shown.     

Über Perowskitphasen in den Systemen AO?SE2O3?UO2.x mit A = Erdalkali und SE = Seltene Erden,La und Y. IV. Verbindungen der Zusammensetzung Sr2SE0,67UO5,5 und Sr2SE0,67UO6

On Perovskite Phases in the Systems AO? SE₂O₃? UO_2,x with A = Alkaline Earth Metal and SE = Rare Earths, La, and Y. IV. Compounds of the Composition Sr₂SE_0,67UO_5,5 and Sr₂SE_0,67UO₆ In the SrO? SE₂O₃? UO_2,x-system the formation of slightly monoclinic distorted rhombic perovskite phases Sr₂SEU⁵⁺O_5,5 is observed. According to the results of the spectroscopic investigations the pentavalent uranium is octahedrally surrounded by oxygen. There are three kinds of U? O-octahedrons to distinguish. By oxydation of Sr₂SE_0,67UO_5,5 the cubic perovskite phases Sr₂SE_0,67UO₆ with hexavalent uranium are obtained. – The structural relations between the perovskites A₂SE_0,67UO_5,5 and A₂SE_0,67UO₆ with A = Ba, Sr are discussed.     

Gibt es „Wolframylgruppierungen”︁? Über Perowskitphasen im System Ba2Y0,67UO6?Ba2CaWO6

Do ? Wolframyl Groups ”? Exist? On Perovskite Phases in the System Ba₂Y_0,67UO₆ ? Ba₂CaWO₆ In the system Ba₂Y_{0.67(1? x)}Ca_xU_{1? x}W_xO₆ a solid solution series is formed up to x ? 0.85. The properties are studied by x-ray and spectroscopic methods.     

Über hexagonale Perowskite mit Kationenfehlstellen. III Strukturbestimmungen an Verbindungen vom Typ Ba2B □2/3 ReVIIO6

On Hexagonal Perovskites with Cationic Vacancies. III. Structure Determination on Compounds of Type Ba₂B □_2/3 Re^VIIO₆ Compounds of Type Ba₂B □_2/3 Re^VIIO₆ with B^III = rare earth, Y. Sc, In belong to the group of hexagonal perovskite stacking polytypes. For B^III = Gd, Y structure determinations with powder data have been performed. The refined R′ factors are 9.11% for Ba₂Gd1/3□_2/3ReO₆ and 12.07% for Ba₂Y1/3□_2/3ReO₆. The structure represents a rhombohedral 12 L type (space group R3 m) with the sequence hhcchhcchhcc. The lattice contains groups of three octahedra connected by common faces which are linked together by a single octahedron via common vertices. In the block of three face-sharing octahedra the central octahedral lattice site is vacant and the two outer positions are occupied by the rhenium atoms. According to this distribution direct contact of occupied face-sharing octahedra is absent.     

Über hexagonale Perowskite mit Kationenfehlstellen. XXIX. Die Struktur von Ba4ScReW□O12 – zur Funktion von oktaedrischen Kationenfehlstellen in Perowskitstapelvarianten

On Hexagonal Perovskites with Cationic Vacancies. XXIX. Structure of Ba₄ScReW□O₁₂ On the Function of Octahedral Cationic Vacancies in Perovskite Stacking Polytypes The hexagonal perovskite stacking polytype Ba₄ScReW□O₁₂ crystallizes in a rhombohedral 12 L structure (space group R3 m; sequence (hhcc)₃). The refined, intensity related R′ value is 6.6%. The octahedral net consists of blocks of three face connected octahedra with a central vacancy, in the two outer positions the rhenium and tungsten atoms are located; this units are linked via common corners by single octahedra, occupied with scandium.     

Detection of arsenic-containing hydrocarbons in canned cod liver tissue

Arsenic is a metalloid well known to be potentially toxic depending of its species. Lipid-soluble arsenicals (arsenolipids) are present in a wide range of biological samples in which they could play a role in the biosynthesis of organoarsenic compounds from inorganic arsenic compounds. Arsenolipids have recently attracted considerable interest. In order to gain deeper insights into the impact of arsenolipids new analytical approaches for reliable determination of this class of arsenic-containing hydrocarbons in various matrices are needed.High concentrations of arsenolipids were found in seafood which served as sample material in this study. We report the investigation of three arsenolipids found in canned cod liver from which they were extracted and purified by solid phase extraction (SPE) using a silica gel column and ethyl acetate/methanol as eluent. Analytical studies were conducted by means of gas chromatography coupled with ICP-MS, MIP-AES and EI-qMS and by TOF-MS. The results obtained by GC-ICP-MS and GC-MIP-AES showed the existence of numerous arsenic compounds in the SPE fractions collected. Three major peaks were found within a retention time window between 10 and 25 min. The presence of arsenic compounds in the fish tissue could be confirmed using GC-EI-qMS analysis. Corresponding information of the molecular weights of the major arsenic species were provided by TOF-MS which allows highly accurate mass determinations. The results showed the presence of the arsenic-containing hydrocarbons with the following molecular formulas: C₁₇H₃₇AsO (calculated for [M+H]⁺ 333.2133; found 333.2136; Δm = 0.90 ppm); C₁₉H₄₁AsO (calculated for [M+H]⁺ 361.2446; found 361.2446; Δm = 0.00 ppm); C₂₃H₃₇AsO (calculated for [M+H]⁺ 405.2133; found 405.2145; Δm = 2.96 ppm). Suggestions for the corresponding structures are discussed.     

Über die Polymorphie der Wolframperowskite Ba2SE0,67WO6

Polymorphism of Tungsten Perovskite Compounds Ba₂SE_0,67WO₆ The compounds Ba₂SE_0,67WO₆ with SE = Gd? Lu are polymorphic. Above 1200°C the instable cubic modification (ordered perovskit with 4 formula units Ba₂SE_0,67□_0,33WO₆ per cell) transforms irreversibly into a hexagonal modification with completely filled cationic lattice. For Ba₂Eu_0,67WO₆ the transformation is incomplete. With SE = Nd and Sm only the cubic modification is formed.     

Über geordnete Perowskite mit Kationenfehlstellen. XI. Verbindungen vom Typ ABB□1/4WVIO6 ≙ ABIIB□WO24 mit AII,BII = Ba,Sr

On Ordered Perovskites with Cationic Vacancies. XI. Compounds of Type A B B □_1/4W^VIO₆ ? A B^IIB □W O₂₄ with A^II, B^II = Ba, Sr Depending on the ionic radii of the two and three valent cations in the perovskites of type ABB □_1/4W^VIO₆ ?; AB^IIB □WO₂₄ order disorder phenomena are present. The results of the x-ray and vibrational spectroscopic investigations as well as the diffuse reflectance spectra and the visible photoluminescence are reported.