bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ein zweikerniger Zinkkomplex mit einem Dithioacetal‐Brückenliganden
Authors: He Guosen , Vahrenkamp Heinrich 
Published: December 2006

AbstractA Dinuclear Zinc Complex with a Bridging Dithioacetal LigandThe pyrazolyl‐bis(thioimidazolyl)borate ligand L1 of the complex [L1Zn‐OClO3] is partly decomposed upon attempts to replace the perchlorate ion by p‐nitrophenolate in a solution containing dichloromethane. As a result, two equivalents of the released mercaptoimidazole react with dichloromethane to form a dithioacetal. This in turn is bound via its two nitrogen donors to two L1˙Zn units forming the title complex, which was identified by a structure determination.
Hydrothermal Synthesis and Crystal Structure of Novel Alkali Trimolybdates
Authors: Michailovski Alexej , Patzke Greta R. 
Published: December 2006

AbstractNovel alkali trimolybdates of the triclinic (M, M′)2Mo3O10 (M = Rb; M′ = K, Cs) type were obtained through a systematic hydrothermal approach based on the reaction of MoO3 with alkali halide solutions at 180 °C. The crystal structures were determined from X‐ray single crystal data. The alkali trimolybdates extend the family of known alkali trimolybdates in an unexpected fashion, because they contain a distorted variation of [Mo3O10]2− chains as a key structural motif that has only been found in a single compound before, namely ethylenediammonium trimolybdate, (C2H10N2)[Mo3O10]. The applied hydrothermal strategy is discussed in the general context of systematic pathways to polyoxomolybdates. Furthermore, the templating role of the alkali cations and their interaction with the polyoxomolybdate surroundings is compared to (C2H10N2)[Mo3O10] in terms of electrostatic calculations.
The Crystal Structure of Trimethyl Borate by Neutron and X‐ray Powder Diffraction
Authors: Hartl M. A. , Williams D. J. , Acatrinei A. I. , Stowe A. , Daemen Luke L. 
Published: December 2006

AbstractThe crystal structure of one of the simplest organoboron compounds, trimethyl borate does not appear to have been determined hitherto. The compound is of interest for the study of π‐donor ligands and their interaction with the π‐acceptor behavior of trigonal boron and the consequences of such interactions on molecular structure. We used powder neutron (with isotopically labeled material) and X‐ray diffraction to determine the crystal structure of trimethyl borate at 15 K and 200 K (neutron) and 200 K (X‐ray). The material is hexagonal (Z = 2) with a = b = 6.950(8) Å and c = 6.501(3) Å at 15 K. The unit cell volume is 272.00(1) Å3. The space group is P63/m (SG 176) at 15 K and 200 K. This is the first crystal structure solved on the Neutron Powder Diffractometer (NPDF) at the Lujan Center.
On the Complexes of Bis(trifluoromethyl)ditellurium, Te2(CF3)2, with Halide Ions – A Crystallographic Study of the Pseudo‐trihalides [PNP][(TeCF3)2X] (PNP = Bis(triphenylphosphoranyliden)ammonium; X = Cl, Br, I)
Authors: Fischer Hendrik T. M. , Naumann Dieter , Tyrra Wieland 
Published: December 2006

AbstractThe anions [(TeCF3)2X]− (X = Cl, Br, I) resemble the trihalides [I2X]− in the solid state and show similar dynamic behaviour in solution. All three compounds crystallize iso‐structurally in the triclinic space group ${\rm P}{\bar 1}$ with Z = 2 and exhibit cell dimensions according to the sizes of the halogen atoms.
Synthesis and Crystal Structure of a Dinuclear Titanium(IV) Complex containing an Allopyranosidato Ligand
Authors: Küntzer Daniela , Tschersich Sebastian , Heck Jürgen 
Published: December 2006

AbstractThe reaction of methyl‐4,6‐O‐benzylidene‐α‐D‐allopyranoside (α‐MeBAH2) with trichlorocyclopentadienyltitanium [CpTiCl3] and triethylamine in dichloromethane led to the dinuclear complex [(CpTiCl2)2‐μ‐(α‐MeAG)] (1). 1 was characterized by elemental analysis, 1H NMR spectroscopy as well as single crystal X‐ray diffraction.
Modern Aspects of Pseudohalogen Chemistry: News from CN‐ and PN‐Chemistry
Authors: Brand Harald , Schulz Axel , Villinger Alexander 
Published: December 2006

AbstractThe pseudohalogen concept still provides a powerful tool to understand the correlation between chemical properties, structure and bonding of pseudohalogen species. Starting from a modern version of the pseudohalogen concept, this research report gives an overview on different subjects of CN‐ and PN‐chemistry dealt with in our group. One of our fundamental interests lies in the synthesis and study of structure and bonding of resonance stabilized pseudohalides such as methanides, amides or binary PN‐pseudohalides. The first chapter describes new syntheses of alkaline dinitroso‐ and nitro(nitroso)cyanomethanides, methanide‐based ionic liquids and their chemical properties. The second chapter deals with azaphospholes which can be considered (i) as resonance stabilized dimers of P‐analogues of covalent azides in case of the triazadiphospholes or (ii) as [3+2] cycloaddition product of a hidden PNN 1,3 dipole (P‐analogue of a covalent azide) with dipolarophiles possessing NN or PN moieties. Starting from a [3+2] synthetic tool kit, new PN‐heterocycles (triazadiphospholes and tetrazaphospholes) and a new synthetic approach called GaCl3‐assisted [3+2] cycloaddition are discussed.
Modellbetrachtungen zum Verständnis unerwarteter Eigenschaften der metalloiden Clusterverbindung [Ga84(N(SiMe3)2)20][Li6Br2(THF)20]·2Toluol
Authors: Hartig Jens , Schnepf Andreas , de Jongh L. Jos , Bono David , Schnöckel Hansgeorg 
Published: December 2006

AbstractTowards the Understanding of the Unexpected Properties of the Metalloid Cluster Compound [Ga84(N(SiMe3)2)20][Li6Br2(THF)20]·2ToluolIn several short communications we have recently reported on the electrical and superconducting properties of the crystalline title compound 1 which contains anionic Ga84R20‐moieties.Here we present a collection of these results, complemented and interpreted by using DFT‐calculations on model clusters (Ga84(NH2)20−). These calculations allowa) a first insight into the dynamics of the Ga84‐moieties (e.g. a rotation of the central Ga2‐dumbbell) and thus an explanation of the temperature‐dependent Ga‐NMR‐spectra described recently, andb) estimations on the lattice energy of 1 and its resulting unexpected energetic stabilization compared to metallic gallium. A possible contribution of the cations in the electrical conduction mechanism of 1 can also be made feasible with model calculations.The basis for all the results presented is to be found in the “perfect” arrangement of nanoscopic Ga84‐clusters in the crystal. This theoretically predicted condition for superconductivity in a “chain” of identical metal cluster molecules is a requirement which can hardly be realized by means of physical fabrication methods. Therefore, on the one hand the results presented here make for some disillusionment in the field of nanoscience, but on the other hand, especially in the field of synthetic chemistry, they present rewarding challenges for fundamental work in the future.
Zwei metallreiche Phosphide – Die Kristallstrukturen von Mg8Ir23P8 und Mg13Pt26P10
Authors: Löhken Anke , Imre Anette , Mewis Albrecht 
Published: December 2006

AbstractTwo Metal‐rich Phosphides – The Crystal Structures of Mg8Ir23P8 and Mg13Pt26P10Mg8Ir23P8 (a = 8.586(4), b = 16.998(7), c = 3.959(2) Å) and Mg13Pt26P10 (a = 8.834(2), b = 21.154(4), c = 4.074(1) Å) crystallize in new structure types (Pbam, Z = 1), which were determined by single crystal methods. In the Ir compound four of seven crystallographically different Ir atoms build up cuboctahedra centered by other Ir atoms. The cuboctahedra are connected with each other via common faces to strands along [001] and they are linked with Ir5 square pyramids centered by P atoms to a three‐dimensional network, in which some of the Ir atoms are part of both polyhedra. The Mg atoms are situated in the holes of the network coordinated by 14 nearest neighbours. The structure of Mg13Pt26P10 is quite similar and contains cuboctahedra too, but they are formed by both kinds of metal atoms building two different polyhedra. The first type is centered by Pt atoms, whereas the centers of the other one are occupied by Mg atoms and P2 dumb‐bells with a statistical distribution. The cuboctahedra are linked with each other via common faces along [001] and edges along [100] and they are connected with Pt5 square pyramids centered by P atoms in a similar fashion like in Mg8Ir23P8.
A Sterically Hindered Phosphonic Acid with a Hydrogen‐Bonded Cage Structure: [4‐tert‐Bu‐2,6‐Mes2‐C6H2P(O)(OH)2·H2O]4
Authors: Nolde Christof , Schürmann Markus , Mehring Michael 
Published: December 2006

AbstractThe synthesis and molecular structure of the novel phosphonic acid 4‐tert‐Bu‐2,6‐Mes2‐C6H2P(O)(OH)2 (1) is reported. Compound 1 crystallizes in form of its monohydrate as a hydrogen‐bonded cluster (1·H2O)4 comprizing four phosphonic acid molecules (O···O 2.383(3)‐3.006(4) Å). Additionally, sterically hindered terphenyl‐substituted phosphorus compounds of the type 4‐tert‐Bu‐2,6‐Mes2‐C6H2PR(O)(OH) (5, R = H; 7, R = O2CC6H4‐3‐Cl; 9, R = OEt) were prepared, which all show dimeric hydrogen‐bonded structures with O···O distances in the range 2.489(2)–2.519(3) Å. Attempts at oxidizing 5 using H2O2, KMnO4, O3, or Me3NO in order to give 1 failed. Crystallization of 5 in the presence of Me3NO gave the novel hydrogen bonded aggregate 4‐tert‐Bu‐2,6‐Mes2‐C6H2PH(O)(OH)·ONMe3 (6) showing an O–H···O distance of 2.560(4) Å.
Synthesis and Crystal Structure of In(OH)(SeO3)
Authors: Paterson Brian , Harrison William T. A. 
Published: December 2006

AbstractIn(OH)(SeO3), prepared by a hydrothermal reaction, crystallizes in a new structure type containing cis InO4(OH)2 octahedra. These groups share both corners (via OH) and edges (via O) to result in a layered motif containing octahedral 8‐ring holes that resembles a single layer of the hollandite structure. The selenium atoms [as pyramidal (SeO3)2− selenite groups] decorate the 8‐ring holes and crosslink the sheets, leading to a three‐dimensional structure. Crystal data: In(OH)(SeO3), Mr = 258.79, triclinic, ${\rm P}{\bar 1}$ (No. 2), a = 5.6523 (2) Å, b = 7.9598 (3) Å, c = 8.0911 (3) Å, α = 87.925 (2)°, β = 79.679 (2)°, γ = 83.201 (3)°, V = 355.58 (2) Å3, Z = 4, R (F) = 0.023, wR (F2) = 0.054.
Synthesis, Structure, and Properties of the High‐Pressure Modification of CePdSn – a 5 K Antiferromagnet
Authors: Heymann Gunter , Riecken Jan F. , Rayaprol Sudhindra , Christian Sandra , Pöttgen Rainer , Huppertz Hubert 
Published: December 2006

AbstractThe high‐pressure (HP) modification of CePdSn was synthesized under multianvil high‐pressure (10.5 GPa) high‐temperature (1100 °C) conditions from the normal‐pressure (NP) modification. The structures of both modifications were studied by X‐ray powder and single crystal diffraction: TiNiSi type, Pnma, a = 754.1(2), b = 470.6(1), c = 798.4(3) pm, wR2 = 0.0333, 945 F2 values, 20 variables for NP‐CePdSn and ZrNiAl type, $P{\bar 6}{\rm 2}m$, a = 760.03(5), c = 416.06(3) pm, wR2 = 0.0443, 248 F2 values, 13 variables for HP‐CePdSn. The structural chemistry of both modifications is goverened by platinum centered trigonal prisms. The platinum and tin atoms in NP‐CePdSn and HP‐CePdSn build up a three‐dimensional [PdSn] network in which the cerium atoms fill channels. Susceptibility measurements on HP‐CePdSn reveal an experimental magnetic moment of 2.55(1) μB/Ce atom in the paramagnetic region. At 5 K a paramagnetic‐to‐antiferromagnetic transition is evident from magnetization and specific heat measurements.
Studien zur Reaktion von [Me2AlP(SiMe3)2]2 mit basenstabilisierten Organogalliumchloriden und ‐hydriden
Authors: Matar Madhat , Schulz Stephan , Flörke Ulrich 
Published: December 2006

AbstractInvestigations on the Reactivity of [Me2AlP(SiMe3)2]2 with Base‐stabilized Organogalliumhalides and ‐hydrides[Me2AlP(SiMe3)2]2 (1) reacts with dmap−Ga(Cl)Me2, dmap−Ga(Me)Cl2, dmap−GaCl3 and dmap−Ga(H)Me2 with Al‐P bond cleavage and subsequent formation of heterocyclic [Me2GaP(SiMe3)2]2 (2) as well as dmap−AlMexCl3−x (x = 3 8; 2 3; 1 4; 0 5). The reaction between equimolar amounts of dmap−Al(Me2)P(SiMe3)2 and dmap−Ga(t‐Bu2)Cl yield dmap−Ga(t‐Bu2)P(SiMe3)2 (6) and dmap−AlMe2Cl (3). 2–8 were characterized by NMR spectroscopy, 2 and 6 also by single crystal X‐ray diffraction.
An Ortho‐silicate‐hydroxide: Rb5[SiO4][OH]
Authors: Kerp Oliver , Möller Angela 
Published: December 2006

AbstractRb5[SiO4][OH] crystallizes in the monoclinc space group C2/m with a = 737.3(1) pm, b = 1073.7(2) pm, c = 1207.2(2) pm, β = 106.07(2)° and Z = 4 (single crystal data; R1= 0.0681 all data). Layers of edge‐connected distorted trigonal prismatic [(OH)Rb6] entities and isolated tetrahedral [SiO4] units present the main structural features of this unprecedented structure type.
First Observation of an Inverse Ruddlesden‐Popper Series: (A3n+1ONn−1)Bin+1 with A = Sr, Ba and n = 1, 3
Authors: Gäbler Frank , Prots Yurii , Niewa Rainer 
Published: December 2006

AbstractSingle crystals ((Ba0.78(1)Sr0.22)4O)Bi2 and ((Ba0.62(1)Sr0.38)10N2O)Bi4 were successfully prepared from melt beads of Ba, Sr, and Bi in nitrogen atmosphere with oxygen impurities. The phases can be prepared in single phase from the appropriate mixtures of alkaline‐earth metal, bismuth, and bismuth oxide upon heating in pure nitrogen atmosphere. ((Ba0.78(1)Sr0.22)4O)Bi2 crystallizes in the K2NiF4 structure type (space group I4/mmm, No. 139, a = 522.34(5) pm, c = 1844.0(2) pm, Z = 2, Rgt(F) = 0.039) with layers of vertex‐sharing octahedra ((Ba,Sr)4/2Ba2O). ((Ba0.62(1)Sr0.38)10N2O)Bi4 crystallizes as an isotype of Sr4Ti3O10 (space group I4/mmm, No. 139, a = 531.3(1) pm, c = 3983.2(4) pm, Z = 2, Rgt(F) = 0.050) containing slabs of three layers of vertex‐sharing octahedra further connected via corners. These compounds are interpreted in terms of members of an inverse Ruddlesden‐Popper series with the general formula n (A3ONn−1)Bi · ABi or (A3n+1ONn−1)Bin+1, respectively, with n = 1, 3. Partial order of the alkaline‐earth metal ions is analyzed.
Zum chemischen Transport und zur Kristallstruktur von Seltenerdmetallantimonaten(V) – SESbO4
Authors: Gerlach Sylvia , Cardoso‐Gil Raul , Milke Edgar , Schmidt Marcus 
Published: December 2006

AbstractChemical Vapour Transport and Crystal Structure of Rare‐Earth Antimonates(V) – RESbO4Single crystals of the compounds RESbO4 (RE = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Lu) were obtained by endothermic chemical transport with TeCl4 as transport agent. The composition of the gas phase has been studied using mass spectrometry. The crystal structures were solved and refined from single crystal X‐ray diffraction data. Praseodym antimonate crystallizes depending on temperature in two modifications: β‐PrSbO4 (space group P21/n (no. 14), Pearson symbol mP24, a = 531.23(2) pm, b = 508.68(2) pm, c = 1281.56(5) pm, β = 92.001(6)°)) and α‐PrSbO4 (space group P21/c (no. 14), Pearson symbol mP24, a = 766.35(3) pm, b = 551.96(3) pm, c = 767.27(3) pm, β = 100.931(3)°). NdSbO4, SmSbO4 und EuSbO4 are isostructural to α‐PrSbO4.
(C5H14N2)[Zn3(HPO4)4], a New 3D Open‐framework Zincophosphate Synthesized by Hydrothermal Reversible Transformation of (C5H14N2)[Zn2(HPO4)3]·H2O
Authors: Wiebcke Michael 
Published: December 2006

AbstractIn the system ZnO/H3PO4/H2O/1,4‐diazacycloheptane (C5H12N2), a new zincophosphate (ZnPO), (C5H14N2)[Zn3(HPO4)4] (I), was prepared by hydrothermal transformation (180 °C) of the known ZnPO hydrate (C5H14N2)[Zn2(HPO4)3]·H2O (II). The thermally‐induced transformation is reversible; upon keeping the heterogeneous mixture of I and mother liquor at 80 °C recrystallization of II was observed. Single‐crystal X‐ray crystallography revealed that I possesses a unique three‐dimensional (3D) open‐framework structure built from corner‐linked ZnO4 and HPO4 tetrahedra. The (3,4)‐connected framework of I differs considerably from the 3D open‐framework ZnPO structure of II. Crystal data for I: Monoclinic system, space group Cc (No. 9) , Z = 4, a = 9.1389(6), b = 23.627(2), c = 9.3073(6) Å, β = 109.463(7)°, T = 298 K.
The Sialons MLn[Si4−xAlxOxN7−x] with M = Eu, Sr, Ba and Ln = Ho‐Yb – Twelve Substitution Variants with the MYb[Si4N7] Structure Type
Authors: Lieb Alexandra , Kechele Juliane A. , Kraut Robert , Schnick Wolfgang 
Published: December 2006

AbstractThe oxonitridoalumosilicates (so‐called sialons) MLn[Si4−xAlxOxN7−x] with M = Eu, Sr, Ba and Ln =Ho, Er, Tm, Yb were obtained by the reaction of the respective lanthanoid metal, the alkaline earth carbonates or europium carbonate, resp., AlN, “Si(NH)2” and MCl2 as a flux in a radiofrequency furnace at temperatures around 2100 °C. The compounds MLn[Si4−xAlxOxN7−x] are relevant for the investigation of substitutional effects on the materials properties due to their ability of tolerating a comparatively large phase width up to x ≈ 2.0(5).The crystal structures of the twelve compounds were refined from X‐ray single crystal data and X‐ray powder data and are found to be isotypic to the MYb[Si4N7] structure type. The compounds crystallize in space group P63mc (no. 186, hexagonal) and are made up of chains of so‐called starlike units [N[4](SiN3)4] or [N[4]((Si,Al)(O,N)3)4], respectively. These units are formed by four (Si,Al)(N/O)4 tetrahedra sharing a common central nitrogen atom. The structure refinement was performed utilizing an O/N‐distribution model according to Paulings rules, i.e. nitrogen was positioned on the four‐fold bridging site and nitrogen and oxygen were distributed equally on both of the two‐fold bridging sites, resulting in charge neutrality of the compound. The Si and Al atoms were distributed equally on their two crystallographic sites, referring to their elemental proportion in the compound, due to being poorly distinguishable by X‐ray methods. The chemical compositions of the compounds were derived from electron probe micro analyses (EPMA).
Chloro‐N′,N′‐dimethylformamidinium‐(dimethylcyanamid)trichloroberyllat, [Me2NC(Cl)NH2]+[BeCl3(NCNMe2)]−
Authors: Neumüller Bernhard , Dehnicke Kurt 
Published: December 2006

AbstractChloro‐N′,N′‐dimethylformamidinium‐(dimethylcyanamide)trichloroberyllate, [Me2NC(Cl)NH2]+[BeCl3(NCNMe2)]−Chloro‐N′,N′‐dimethylformamidinium‐(dimethylcyanamide)trichloroberyllate, [Me2NC(Cl)NH2]+[BeCl3(NCNMe2)]− was prepared from BeCl2 with two equivalents of dimethylcyanamide in CH2Cl2 suspension. The compound was characterized by X‐ray crystallography and by IR spectroscopy. Space group ${\rm P}{\bar 1}$, Z = 2, lattice dimensions at 193 K: a = 620.7(1), b = 744.9(2), c = 1520.3(3) pm, α = 96.87(2)°, β = 100.41(2)°, γ = 100.17(2)°, R1 = 0.0443. Cations and anions form N–H…Cl hydrogen bridges along [010].
Novel Trinuclear MnII/MnII/MnII Complexes – Crystal Structures and Catalytic Properties
Authors: Kloskowski Michael , Pursche Daniel , Hoffmann Rolf‐Dieter , Pöttgen Rainer , Läge Mechtild , Hammerschmidt Adrienne , Glaser Thorsten , Krebs Bernt 
Published: December 2006

AbstractThe trinuclear manganese(II) complexes [Mn3(L1)2(μ‐OAc)4]·2Et2O {HL1 = (1‐hydroxy‐4‐nitrobenzyl)((2‐pyridyl)methyl)((1‐methylimidazol‐2‐yl)methyl)amine} (1·2EtOH), [Mn3(L2)2(μ‐OAc)4] {HL2 = ((1‐methylimidazol‐2‐yl)methyl)(1‐hydroxybenzyl)amine} (2) and [Mn3(L3)2(μ‐OAc)6] {L3 = bis(1‐methylimidazol‐2‐yl)methanone} (3) were synthesized. The compounds were characterized by X‐ray crystallography, mass spectrometry, IR, UV‐vis spectroscopy, and elemental analysis. The manganese atoms in 1 and 2 are bridged by phenol moieties of the ligands and acetates. In 3 they are only bridged by acetates in a mono‐ and bi‐dentate way. The resulting Mn···Mn distances are 3.233(1) Å (1), 3.364(1) Å (2) and 3.643(7) Å (3). In the present compounds different limiting cases for the phenomenon of the carboxylate shift are realized. Besides symmetric mono‐ and bi‐dentate bridging an unusual intermediate is also observed. 1·2EtOH is the first example of a trinuclear model for the OEC that shows catalase activity. Furthermore it was characterized by temperature dependent magnetic susceptibility measurements and a total spin ground state of St = 5/2 was found. The results for 1 reveals antiferromagnetic coupling between the central and the terminal manganese ions, with J = −1.2 cm−1, g = 2.00 (fixed), χTIP = 150×10−6 cm3mol−1.
Cobalt Centered Trigonal RE6 Prisms and Mg4 Clusters as Basic Structural Units in RE4CoMg (RE = Y, La, Pr, Nd, Sm, Gd–Tm)
Authors: Tuncel Selcan , Hoffmann Rolf‐Dieter , Chevalier Bernard , Matar Samir F. , Pöttgen Rainer 
Published: December 2006

AbstractThe new rare earth metal rich intermetallic compounds RE4CoMg (RE = Y, La, Pr, Nd, Sm, Gd–Tm) were prepared via melting of the elements in sealed tantalum tubes in a water‐cooled sample chamber of a high‐frequency furnace. The compounds were investigated by X‐ray diffraction of powders and single crystals: Gd4RhIn type, $F{\bar 4}{\rm 3}m$, a = 1428.38(9) pm, wR2 = 0.0638, 680 F2 values, 20 variables for La4CoMg, a = 1399.5(2) pm, wR2 = 0.0584, 589 F2 values, 20 variables for Pr4CoMg, a = 1390.2(3) pm, wR2 = 0.0513, 634 F2 values, 20 variables for Nd3.90CoMg1.10, a = 1381.0(3) pm, wR2 = 0.0730, 618 F2 values, 22 variables for Sm3.92Co0.93Mg1.08, a = 1373.1(4) pm, wR2 = 0.0586, 611 F2 values, 20 variables for Gd3.92CoMg1.08, a = 1362.1(3) pm, wR2 = 0.0576, 590 F2 values, 20 variables for Tb3.77CoMg1.23, a = 1344.8(2) pm, wR2 = 0.0683, 511 F2 values, 20 variables for Dy3.27CoMg1.73, and a = 1343.3(2) pm, wR2 = 0.0560, 542 F2 values, 20 variables for Er3.72CoMg1.28. The cobalt atoms have trigonal prismatic rare earth coordination. Condensation of the CoRE6 prisms leads to a three‐dimensional network which leaves larger voids that are filled by regular Mg4 tetrahedra at a Mg–Mg distance of 316 pm in La4CoMg. The magnesium atoms have twelve nearest neighbors (3 Mg + 9 RE) in icosahedral coordination. In the structures with Nd, Sm, Gd, Tb, Dy, and Er, the RE1 positions which are not involved in the trigonal prismatic network reveal some RE1/Mg mixing and the Sm3.92Co0.93Mg1.08 structure shows small cobalt defects. Considering La4CoMg as representative of all studied systems an analysis of the chemical bonding within density functional theory closely reproduces the crystal chemistry scheme and shows the role played by the valence states of the different constituents in the electronic band structure. Strong bonding interactions were observed between the lanthanum and cobalt atoms within the trigonal prismatic network.
Characterization of Two Zincophosphates (UH‐6 and UH‐10) Synthesized using the Cobalt(III) Sarcophagine Complex as Structure‐directing Agent
Authors: Klingelhöfer Stefan , Wiebcke Michael , Behrens Peter 
Published: December 2006

AbstractThe novel zincophosphates UH‐6 (sum formula |[Co(diAMHsar)]| [Zn2(HPO4)3(PO4)] · H2O) and UH‐10 (sum formula |([Co(diAMHsar)])2| [{Zn2(HPO4)3(PO4)}2] · H2O) were synthesized in hydrothermal syntheses employing the chiral sarcophagine complex [Co(diAMHsar)]5+ as the structure‐directing agent. The inorganic part of UH‐6 consists of pearl‐like chains of alternating [ZnO4] and [PO4] tetrahedra, which are connected to the incorporated cobalt complex via numerous hydrogen bonds. UH‐10 was synthesized under similar conditions, but at higher reaction temperatures. In consequence, the crystal structures of UH‐6 and UH‐10 are closely related, although systematic disorder in UH‐10 and the lower symmetry result in a unit cell twice as large as the corresponding unit cell of UH‐6. Interestingly, in both zincophosphates only one enantiomer of the cobalt complex is present, despite the fact that a racemic mixture of the complex salt is used for synthesis. Thermogravimetric analysis and powder X‐ray diffraction of a thermally treated sample of UH‐6 reveals a phase transformation at ca. 300 °C.