bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wind turbine performance under icing conditions
Authors: Hochart Clement , Fortin Guy , Perron Jean , Ilinca Adrian 
Published: October 2007

AbstractThe wind energy market is in full growth in Quebec but technical difficulties due to cold climate conditions have occurred for most of the existing projects. Thus, icing simulations were carried out on a 0.2 m NACA 63 415 blade profile in the refrigerated wind tunnel of the Anti‐icing Materials International Laboratory (AMIL). The shapes and masses of the ice deposits were measured, as well as the lift and drag forces of the iced profiles. Scaling was carried out based on the 1.8 MW–Vestas V80 wind turbine technical data, for three different radial positions and two in‐fog icing conditions measured at the Murdochville wind farm in the Gaspé Peninsula. For both icing events, the mass of ice accumulated on the blade profile increased with an increase in the radial position. In wet regime testing (first icing event), glaze formed mostly near the leading edge and on the pressure side. It also accumulated by run‐off on the trailing edge of the outer half of the blade. In dry‐regime testing (second icing event), rime mostly accreted on the leading edge and formed horns. For both icing events, when glaze or rime accreted on the blade profile, lift decreased and drag increased. A load calculation using the blade element theory shows that drag force on the entire blade becomes too large compared to lift, leading to a negative torque and the stop of the wind turbine. Torque reduction is more significant on the outer third of the blade. Setting up a de‐icing system only on the outer part of the blade would enable significant decrease of heating energy costs. Copyright © 2007 John Wiley & Sons, Ltd.
Zur Kristallchemie der Oxorhenate
Authors: Müller‐Buschbaum Hanskarl 
Published: October 2007

AbstractDas Review behandelt die Kristallchemie der Oxorhenate. Im Gegensatz zur Kristallchemie der kürzlich diskutierten Oxorhodate tritt Rhenium in vielfältiger Koordination auf. Zu nennen sind quadratisch planare Polygone, trigonale Bipyramiden, Tetraeder und Oktaeder. Ausgehend von den Oxiden ReO2, Re2O7, Re1,16O3, Re3O10 and ReO3 wird gezeigt, daß Oxorhenate zueinander isolierte Tetraeder, Oktaeder, Re2O10‐ und Re2O9‐Baugruppen aufweisen. Die Polyeder von Sauerstoff um Rhenium treten isoliert zueinander auf oder bilden eindimensionale Ketten, zweidimensionale Netze und dreidimensionale Gerüststrukturen. Rhenium adaptiert die Kristallstrukturen der Perowskite, des Fluorits, des Pyrochlors, Rutils und der Stapelvarianten der Perowskite. Spezielle Eigenschaften weisen die Quecksilber‐Oxorhenate (HgReO4, Hg2ReO5, Hg5Re2O10) mit – Hg+‐Hg+ – Gruppen und die Selten Erdmetall‐Oxorhenate (Ln2ReO5, Ln3Re2O9, Ln5Re2O12) mit deutlichen Re‐Re – Wechselwirkungen auf.PbRe2O8 und BiReO4 sind bemerkenswert mit Blick auf einseitig offene Polyeder, die durch lone pair – Aktivität am Pb2+ und Bi3+ hervorgerufen werden. Die Lagen der lone pair (e2−–Punktladung) werden durch Berechnungen des Madelunganteils der Gitterenergie ermittelt.
Synthesis and Crystal Structure of a Novel A‐Zeolite‐like Copper Complex: [Cu12(SO4)12(3H2O)]·H2O
Authors: Zhang Xing‐Jing , Xing Yong‐Heng , Han Jing , Ge Mao‐Fa , Niu Shu‐Yun 
Published: October 2007

AbstractThe reaction of CuBr2, N(CH2CH2COOH)3, and Nd(NO3)3·6H2O in water adjusted pH = 5‐6 with H2SO4 at constant 55 °C afforded a novel three‐dimensional coordination complex [Cu12(SO4)12(3H2O)]·H2O, (1), which was characterized by IR, elemental analysis, and X‐ray diffraction. The crystal structure data of 1 as follows: Cubic, ${\rm Fm}{\bar 3}{\rm c}$, a = b = c = 24.018(2) Å, V = 13855 (3) Å3, Z = 968, Dc = 1.905 g/cm3, F(000) = 7712, R1 = 0.0352, wR2 = 0.0866 (I > 2σ(I)), R1 = 0.0449, wR2 = 0.0927 (for all data) and S = 1.075. The analysis of crystal structure indicates that the structure of 1 is similar to that of silicate zeolite (Na12[Al12Si12O48]·27H2O).
A Three‐Dimensional Lead 2,6‐Dihydroxybenzoate with Channels
Authors: Thirumurugan A. , Suchethan P. A. , Cheetham A. K. , Rao C. N. R. 
Published: October 2007

AbstractA lead 2,6‐dihydroxybenzoate of the formula Pb(C14H10O8) (I) has been synthesized and characterized by X‐ray crystallography and spectroscopic techniques. (crystal data: monoclinic, space group = Cc (no. 9), a = 11.2155(2), b = 9.2942(2), c = 13.5112(3) Å, β = 96.510(1)°, V = 1399.31(5) Å3, Z = 4). This is the first three‐dimensional metal dihydroxybenzoate structure, comprising 3,6‐connected periodic net and having channels with the dimensions 3.8 × 3.8Å and 10.8 × 3.8Å. The coordination of the PbO8 polyhedron is holodirected and the electron lone pair of the lead is, therefore, not manifested in I. It exhibits photoluminescence in the violet, green and red when excited at 240, 390 and 525 nm, respectively.
Back‐bonding in Organonickel Complexes with Terpyridine Ligands – A Structural Approach
Authors: Hamacher Claudia , Hurkes Natascha , Kaiser André , Klein Axel 
Published: October 2007

AbstractA series of organonickel complexes [(R′terpy)Ni(aryl)]X (R′terpy = derivatives of 2,2′;6′,6″‐terpyridine; R′ = 4‐H, 4‐Cl, 4‐Tol and 4,4′,4″‐tBu3; aryl = 2,6‐dimethylphenyl = Xyl or 2,4,6‐trimethylphenyl = Mes; X = Br or PF6) have been prepared and characterized. The crystal structures exhibit a number of intermolecular H bond type interactions, but the structure determining force seems to be the packing of the aryl co‐ligands. The molecules reveal rather undistorted square planar coordination with a N3C ligand set, the central Ni–N bond being remarkably short, despite the expected strong trans influence of the aryl co‐ligands. The long‐wavelength absorptions were assigned to charge transfer transitions. No emission is observed at ambient temperature in the solid and in solution and at low temperature in glasses.
Scaled Quantum Mechanical Force Fields for the Isoelectronic Molecules CF3X (X = SiH3, PH2, SH, Cl )
Authors: Fernández L. E. , Varetti E. L. 
Published: October 2007

AbstractThe vibrational properties of the CF3X (X = SiH3, PH2, SH, Cl) series of molecules were studied by means of density functional theory (DFT) techniques. After obtaining the optimized geometrical parameters and conformations, the frequencies corresponding to the normal modes of vibration and the associated force constants were calculated. The original force fields in Cartesian coordinates were transformed to local symmetry coordinates and subsequently scaled to reproduce the experimental frequencies. Some trends observed in the experimental data could be explained on the basis of the calculated atomic charges.
Crystal Growth, Single‐Crystal Structure Refinement and Unusual Ligand‐Field Splittings of Lazulite‐Type Oxidephosphates MTi2O2(PO4)2 (M = FeII, CoII, NiII)
Authors: Schöneborn M. , Glaum R. 
Published: October 2007

AbstractSingle crystals of oxidephosphates MTi2O2(PO4)2 [M: Fe (dark red), Co (pinkish red), Ni (green)] with edge‐lengths up to 0.4 mm were grown by chemical vapour transport. FeTi2O2(PO4)2 and CoTi2O2(PO4)2 are isotypic to NiTi2O2(PO4)2. The crystal structure of the latter was previously solved from powder data [FeTi2O2(PO4)2 (data for CoTi2O2(PO4)2 and NiTi2O2(PO4)2 in brackets): monoclinic, P21/c, Z = 2, a = 7.394(3) (7.381(6), 7.388(4)) Å, b = 7.396(2) (7.371(5), 7.334(10)) Å, c = 7.401(3) (7.366(6), 7.340(3)) Å, β = 120.20(3) (120.26(6), 120.12(4))°, R1 = 0.0393 (0.0309, 0.0539) wR2 = 0.1154 (0.0740, 0.1389), 2160 (1059, 1564) independent reflections, 75 (76, 77) variables]. The single‐crystal study allowed improved refinement using anisotropic displacement parameters, yielded lower standard deviations for the structural parameters and revealed a small amount of cation disordering. Twinning and cation disordering within the structures are rationalized by a detailed crystallographic classification of the MTi2O2(PO4)2 structure type in terms of group‐subgroup relations. The structure is characterized by a three‐dimensional network of [PO4] tetrahedra and [MIITi2O12] groups formed by face‐sharing of [MIIO6] and [TiO6] octahedra. Electronic absorption spectra of MTi2O2(PO4)2 in the UV/VIS/NIR region show rather large ligand‐field splittings for the strongly trigonally distorted chromophors [MIIO6] (M = Fe, Co, Ni) with interelectronic repulsion parameters beeing slightly smaller than in other phosphates. Interpretation of the spectra within the framework of the angular overlap model reveals a significant second‐sphere ligand field effect of TiIV ions on the electronic levels of the NiII and CoII.
Synthesis, Characterization, and Crystal Structure of new Macromolecule Iron(III) Complex Containing Dimethyl Phosphate, Acetate, and Dimethyl sulfoxide
Authors: Rafizadeh Masoud , Amani Vahid 
Published: October 2007

AbstractThe reaction between a solution of [Fe3O(μ‐OAc)6(H2O)3]Cl·6H2O (1) (OAc = acetate) and TMP (TMP = trimethyl phosphate) in absolute ethanol and DMSO (DMSO = dimethyl sulfoxide), led to the coordination macromolecule ‐[Fe16(μ3O)8(μ3‐OH)4(μ‐OH)4(μ‐DMP)12(μ‐OAc)12(DMSO)4]·2DMSO·1.5H2O (2) (DMP = dimethyl phosphate). This complex was characterized by elemental analysis, IR spectroscopy, and single‐crystal structure. Crystal data for 2 at −153 °C: triclinic, space group ${\rm P}{\bar 1}$, a = 18.185(2), b = 18.349(2), c = 21.976(3) Å, α = 91.633(3)°, ß = 103.833(3)° γ = 96.486(3)°, Z = 2 and R1 = 0.0655.
Ca2Pd2In and Ca2Pt2In with Monoclinic HT‐Pr2Co2Al Type Structure
Authors: Muts Ihor R. , Zaremba Vasyl I. , Rodewald Ute Ch. , Hermes Wilfried , Pöttgen Rainer 
Published: October 2007

AbstractThe metal‐rich indides Ca2Pd2In and Ca2Pt2In were synthesised from the elements in sealed tantalum ampoules in an induction furnace. Both samples were investigated by X‐ray powder and single crystal diffraction: HT‐Pr2Co2Al type, C2/c, a = 1017.6(5), b = 574.1(3), c = 812.7(3) pm, β = 104.54(2)°, wR2 = 0.0344, 590 F2 values for Ca2Pd2In and a = 1004.3(3), b = 568.9(1), c = 813.1(2) pm, β = 104.25(2)°, wR2 = 0.0435, 654 F2 values for Ca2Pt2In with 25 variables per refinement. The structure contain Pd2 (272 pm) and Pt2 (264 pm) dumb‐bells with a trigonal prismatic coordination for each transition metal atom. These AlB2 related slabs are condensed via common edges. Together the palladium and indium atoms build up three‐dimensional [Pd2In] and [Pt2In] polyanionic networks in which the calcium atoms fill larger channels. The bonding of calcium to the network proceeds via shorter Ca–Pd and Ca–Pt contacts. Ca2Pd2In and Ca2Pt2In are Pauli paramagnets.
Synthesis and Characterization of Two New Transition‐Metal Complex Salts of the Wells‐Dawson Polyanion
Authors: Tian Aixiang , Han Zhangang , Peng Jun , Sha Jingquan , Zhai Jiangli , Zhang Pengpeng , Chen Jing , Liu Hongsheng 
Published: October 2007

AbstractTwo new transition‐metal (TM) complex salts of the Wells‐Dawson polyanion: [Cu(2,2′‐bpy)3]2[Cu(2,2′‐bpy)2]2[P2W18O62] (1) and [2,2′‐bpy]8[Fe(2,2′‐bpy)3]8[P2W18O62]4·9H2O (2) (2,2′‐bpy = 2,2′‐bipyridine), have been synthesized under hydrothermal conditions by using pre‐prepared α‐K6P2W18O62·15H2O as a precursor. Crystal data for compound 1: monoclinic, space group C2/c, a = 20.722(4) Å, b = 21.988(4) Å, c = 29.614(6) Å, β = 104.32(3)°, V = 13074(5) Å3, Z = 4; for compound 2: triclinic, space group ${\rm P}{\bar 1}$, a = 15.804(3) Å, b = 27.519(6) Å, c = 27.566(6) Å, α = 72.71(3)°, β = 89.94(3)°, γ = 89.90(3)°, V = 11447(5) Å3, Z = 1. Compounds 1 and 2 have been characterized by single‐crystal X‐ray diffraction, IR spectra, thermogravimetric analysis, XPS spectra and cyclic voltammetry. The two compounds were used as solid bulk modifiers to fabricate bulk‐modified carbon paste electrodes (1‐, 2‐CPE). The electrochemical behaviors of 1‐, 2‐CPE have been studied in detail. The redox behavior of the parent Wells‐Dawson type cluster was maintained completely in compounds 1 and 2.
Mono and Poly‐nuclear Silver(I) Complexes with Thiosaccharin and Triphenylphosphine. Synthesis, Spectroscopic and Structural Characterization of Thiosaccharinato‐bis(triphenylphosphine)silver(I) and Tetrakis{thiosaccharinato(triphenylphosphine)silver(I)}
Authors: Dennehy Mariana , Mandolesi Sandra D. , Quinzani Oscar V. , Jennings Michael 
Published: October 2007

AbstractThe reaction of Ag6(tsac)6 (1) (tsac = thiosaccharinate anion) with triphenylphosphine gives rise to the already reported [Ag(tsac)(PPh3)3] complex (2) and to two new silver‐thiosaccharinate‐phosphine complexes, [Ag(tsac)(PPh3)2] (3) and [Ag4(tsac)4(PPh3)4] (4) (PPh3= triphenylphosphine). Spectroscopic characterization was carried out using IR, UV‐Visible and NMR techniques and confirmed by single crystal X‐ray diffraction. In each complex a singular coordination mode for the thiosaccharinate ligand is observed. The most important features of the different coordination modes of the thionates are discussed. Compound 3 crystallizes in monoclinic system, space group Pn, with a = 11.2293(3) Å, b = 12.7282(3) Å, c = 13.6056(4) Å, β = 94.985(2)°, Z = 2; while crystals of compound 4 are monoclinic, space group P21/n, a = 15.024(3) Å, b = 14.681(3) Å, c = 21.914(4) Å, β = 95.31(3)°, Z = 2. The coordination around the silver atoms in both complexes consists of almost trigonal‐planar arrangements, AgP2S in 3 and AgS2P in 4.
Darstellung und Kristallstruktur des Lithium‐Strontium‐Hydridnitrids LiSr2H2N
Authors: Blaschkowski Björn , Schleid Thomas 
Published: October 2007

AbstractSynthesis and Crystal Structure of the Lithium Strontium Hydride Nitride LiSr2H2NLiSr2H2N was synthesized by the reaction of LiH and Li3N with elemental strontium in sealed tantalum tubes at 650 °C within seven days. This second example of a quaternary hydride nitride crystallizes orthorhombically in space group Pnma (no. 62) with the lattice constants a = 747.14(5) pm, b = 370.28(3) pm and c = 1329.86(9) pm (Z = 4). Its crystal structure contains both kinds of anions H− and N3− in a sixfold distorted octahedral metal cation coordination each. The coordination polyhedra [(H1)Sr5Li]10+, trans‐[(H2)Sr4Li2]9+ and [NSr5Li]8+ are connected via edges and corners to form a three‐dimensional network. Two crystallographically different Sr2+ cations exhibit a sevenfold monocapped trigonal prismatic coordination by H− and N3− with [(Sr1)H5N2]9− and [(Sr2)H4N3]11− polyhedra, wheras Li+ shows a nearly planar fourfold coordinative environment ([LiH3N]5−). Cationic double chains of edge‐shared [NSr5Li]8+ octahedra dominate the structure according to $^{1}_{\infty}\rm \{[N(Sr1)_{2/2}(Sr2)_{3/3}Li_{1/1}]^{2+}\}$. Running parallel to the [0 1 0] direction, they are bundled like a hexagonal rod‐packing which is interconnected by H− anions within the (0 0 1) plane first and finally even in the third dimension (i. e. along [0 0 1]). Therefore the structure of LiSr2H2N is compared to that one of the closely related quaternary hydride oxide LiLa2HO3.
Stuffed Graphite‐like vs. Stuffed Diamond‐like Structures of the 18 Valence Electron Compounds REAuSn (RE = Sc, Y, La‐Nd, Sm, Gd‐Lu)
Authors: Lee Changhoon , Whangbo Myung‐Hwan , Köhler Jürgen 
Published: October 2007

Abstract18‐electron compounds REML (RE = rare earth metal; M = Cu, Ag, Au; L = Ge, Sn) can adopt either the stuffed graphite‐like (P63mc) or the stuffed diamond‐like ($F{\bar 4}{\rm 3}m$) structure. To understand why one structure is favored over the other, we carried out density functional theory electronic structure calculations for a number of REAuSn compounds. The stuffed graphite‐like and stuffed diamond‐like structures of an 18‐electron compound REAuSn are quite similar in their electronic structures with the Au atoms best described as existing as anions. The diamond‐like REML becomes possible only when the RE3+ ion is small and the M‐L bond is long.
ErF3‐reiche ternäre Erbiumfluoride mit den schweren Alkalimetallen: I. KEr3F10 und RbEr3F10
Authors: Müller‐Bunz Helge , Schleid Thomas 
Published: October 2007

AbstractErF3‐Rich Ternary Erbium Fluorides with the Heavy Alkali Metals: I. KEr3F10 and RbEr3F10The conversion of erbium trifluoride (ErF3) with chlorides of the heavy alkali metals (ACl; A = K, Rb and Cs) at 700–800 °C in tantalum capsules sealed by arc‐welding surprisingly results in the formation of ErF3‐rich ternary alkali‐metal erbium(III) fluorides with the compositions AEr3F10 (A = K and Rb) or CsEr2F7, respectively. The first‐mentioned compounds are characterized by high coordination numbers at the alkali‐metal cation (CN(A+) = 15 and 16) as well as by a uniform surrounding of the Er3+ cation (CN = 8, square antiprism). In KEr3F10 (cubic, $Fm{\bar 3}m$Fm3m; a = 1154.06(7) pm, Z = 8) eight (F1)− anions always arrange as a cube, whose six faces are each capped by an Er3+ cation. These [(F1)8Er6]10+ groups constitute a cubic closest sphere‐packing with K+ cations in all of the tetrahedral interstices. The [Er6(μ3‐F1)8]10+ units are interconnected via the remainder fluoride anions (F2) to build up a three‐dimensional framework so that the characteristic [ErF8]5− polyhedra (d(Er3+−F−) = 220 – 235 pm) emerge. In RbEr3F10 (hexagonal, P63mc; a = 818.43(5), c = 1336.54(8) pm, Z = 4) the analogous [ErF8]5− polyhedra (d(Er3+−F−) = 219 – 237 pm) initially convene to triple groups [Er3F19]10− through cis‐edge condensation, which are then further connected via F− corners to arrange as a two‐dimensional network perpendicular to the c axis. Finally, the cross‐linking of these layers is achieved by common F− vertices again, such that large cavities apt to take up the Rb+ cations are formed. A second part of these series will report on the syntheses and crystal structures of the ErF3‐poorer AEr2F7‐type representatives with A = K, Rb and Cs.
Aurophilicity in Tetraphenylphosphonium 7,8‐Bis(diphenylphosphino)‐7,8‐dicarba‐nido‐undecaborato‐dibromo‐digold(I) [PPh4][{(PPh2)2‐C2B9H10}(AuBr)2]
Authors: Effendy  , Healy Peter C. , Noack Cassandra L. , Skelton Brian W. , White Allan H. , Young David J. 
Published: October 2007

AbstractReactions of tetraphenylphosphonium dibromoaurate(I) with 1,2‐bis(diphenylphosphino)‐1,2‐dicarba‐closo‐dodecaborane in 2:1 ratio in acetone solution yields brown crystals shown to be the title compound. A single crystal X‐ray study shows coordination of AuBr moieties by the phosphorus atoms of the ligand (Au‐P 2.253(1), 2.246(1); Ag‐Br 2.4041(7), 2.4067(7) Å), permitting a close Au···Au contact (2.9536(3) Å) with concomitant bending of the P‐Au‐Br arrays (173.99(4), 166.14(4)°) and a Br‐Au···Au‐Br torsion of 47.80(2)°.
Synthesis, Crystal Structure and Properties of RbMnO2
Authors: Pfeiffer Steffen , Jansen Martin 
Published: October 2007

AbstractRbMnO2 was prepared via the azide/nitrate route. Stoichiometric mixtures of the precursers (Mn2O3, RbN3 and RbNO3) were heated in a special regime up to 600 °C and annealed at this temperature for 30 h in specially designed silver crucibles. Single crystals have been grown by annealing a 1:1 mixture of Rb2O and MnOx at 585 °C for 1200 h. According to the crystal structure determination Mn3+ is in a square‐pyramidal coordination by oxygen. These [MnO5] units form double chains extending along the crystallographic c‐axis. RbMnO2 shows Curie‐Weiss behaviour down to ∼ 100 K. A fit of the susceptibility data yields an average value of the magnetic moment (per manganese atom) of μeff = 5.33 μB, and θp = –820 K. At 50 K and low field strength onset of ferromagnetic order due to spin canting has been observed.
Synthesis and Structure of BaPtIn3 and BaTl0.63In3.33. Two Contrasting Examples of Preferential Site Occupation in BaAl4‐Type Structures
Authors: Palasyuk Andriy , Corbett John D. 
Published: October 2007

AbstractThe title compounds have been synthesised by high temperature means and characterized by single crystal X‐ray diffraction analysis. The compounds crystallize in the tetragonal structure type of BaAl4, I4/mmm, Z = 2 (a = 4.8130(7), 5.0196(8) Å; c = 11.669(2), 11.900(3) Å for BaPtIn3 and BaTl0.63In3.37, respectively).Platinum and thallium randomly substitute for 50 % of the In in the apical 4e and for 30 % in the basal 4d positions in the two networks, respectively. Consistent with both size and relative electronegativity factors, the basal positions in BaAl4‐type structure are appropriate for substitution by dimensionally and chemically similar atoms (Tl), which is different from the apical sites in which electronegativities or bond strengths are more important (Pt).
Structural and Magnetic Properties of Pr2BaCuO5 Oxide
Authors: Pascual E. Climent , de Paz J. Romero , Puche Regino Sáez 
Published: October 2007

AbstractThe Pr2BaCuO5 oxide has been prepared by using a precursor method. X‐ray and neutron diffraction data reveal that this mixed oxide crystallizes with the so‐called Nd2BaPtO5‐type structure, showing tetragonal symmetry and space group P4/mbm. Magnetic susceptibility, magnetization and specific heat measurements reveal that Pr2BaCuO5 oxide behaves as antiferromagnet, where the Pr3+ and Cu2+ sublattices become simultaneously ordered at 15 K. Preliminary neutron diffraction studies confirm this proposed antiferromagnetic ordering and it can be described by the wave vector k = [0,0,0].
M2B5 or M2B4? A Reinvestigation of the Mo/B and W/B System
Authors: Frotscher Michael , Klein Wilhelm , Bauer Joseph , Fang Chang‐Ming , Halet Jean‐Franois , Senyshyn Anatoliy , Baehtz Carsten , Albert Barbara 
Published: October 2007

AbstractThe literature states different compositions (M/B = 1:2 vs. 2:5) and structures for diborides of molybdenum and tungsten. Using X‐ray and neutron powder diffraction as well as energy and wavelength dispersive electron microprobe analysis, the Mo/B and W/B systems were now reinvestigated. Molybdenum diboride crystallizes as a stoichiometric compound Mo2B4 (formerly described as Mo2B5) in space group $R{\bar 3}m$ (No. 166, a, b = 3.01375(2) Å, c = 20.9541(3) Å), and as a non‐stoichiometric compound MoB2−x (formerly described as MoB2) in P6/mmm (No. 191, a, b = 3.043(2) Å, c = 3.067(2) Å), whereas stoichiometric tungsten diboride W2B4 (formerly described as W2B5) is found to crystallize in space group P63/mmc (No. 194, a, b = 2.9864(4) Å, c = 13.896(2) Å). These results seem to be supported by DFT calculations which show the instability of a hypothetic W2B5.
Komplexe Fluoride von Palladium(II) – eine kurze Übersicht
Authors: Serafin Michael , Müller Bernd G. 
Published: October 2007

AbstractFluor und seine Verbindungen nehmen in vielfacher Hinsicht eine gewisse Sonderstellung ein und sie unterscheiden sich häufig merklich von den schweren Homologen bzw. deren Verbindungen. Dies trifft zum einen für die unterschiedliche Stabilität vergleichbarer Oxidationsstufen – soweit überhaupt zugänglich – als auch zum anderen die im Allgemeinen zu beobachtende Zusammensetzung oder Strukturen der jeweiligen Verbindungen sowohl in binären als auch ternären oder noch komplexeren Systemen zu. Neben dem weitgehend ionischen Bindungscharakter (zumindest bei niederen Oxidationsstufen), der geringen Größe – F− ist das kleinste einfach geladene Anion – spielt – jedenfalls bei Übergangsmetallkomplexen – bisweilen auch noch dessen geringe Ligandenfeldstärke bei der Anordnung der Liganden (Koordinationssphäre) eine wesentliche Rolle. Eines der markantesten Beispiele hierfür stellen die PdII‐Fluoride dar, über die im Folgenden im Rahmen einer kurzen Zusammenfassung berichtet werden soll.
Hydrogen Bonds in Rubidium Amide‐Ammonia(3/2), RbNH2·2/3NH3
Authors: Scheubeck Thomas , Korber Nikolaus 
Published: October 2007

AbstractRubidium amide‐ammonia(3/2), RbNH2·2/3NH3, was synthesized from Rubidiumhydride, RbH, in liquid ammonia at −78 °C. The compound crystallizes in the cubic space group I213 with Z = 4, a = 10.0490(12) Å, and V = 1014.77(20) Å as isometric colorless crystals. The crystal structure was solved from single‐crystal X‐ray data. The structure contains a three‐dimensional network of amide anions and ammonia molecules, which are interconnected via hydrogen bonds.