The New Carbodiimide Li2Gd2Sr(CN2)5 Having a Crystal Structure Related to That of Gd2(CN2)3

The new carbodiimide compounds Li₂RE₂Sr(CN₂)₅ (RE = Sm, Gd, Eu, Tb) were prepared by a straight forward solid state metathesis reaction of REF₃, SrF₂, and Li₂(CN₂) at around 600 °C. The crystal structure of Li₂Gd₂Sr(CN₂)₅ was solved based on X‐ray single‐crystal diffraction data. Corresponding Li₂RE₂Sr(CN₂)₅ compounds were analyzed by isotypic indexing of their powder patterns. The crystal structure of Li₂Gd₂Sr(CN₂)₅ can be well related to that of Gd₂(CN₂)₃, because both structures are based on layered structures composed of close packed layers of [N=C=N]^2– sticks, alternating with layers of metal ions. The crystal structure of Li₂Gd₂Sr(CN₂)₅ can be considered to contain an ABC layer sequence of [N = C=N]^2– layers with the interlayer voids being occupied by (three) distinct types of cations.     

Missing Carbodiimide and Oxide Carbodiimide of Scandium: Sc2(CN2)3 and Sc2O2(CN2)

The new scandium(III) carbodiimides Sc₂(CN₂)₃ and Sc₂O₂(CN₂) were prepared by solid-state metathesis reactions between Li₂(CN₂) and ScCl₃ and, regarding Sc₂O₂(CN₂), Sc₂O₃ was added. The X-ray powder diffraction pattern refinements lead to a trigonal-rhombohedral (R3 c) crystal system for Sc₂(CN₂)₃ and to an orthorhombic (Immm) crystal system for Sc₂O₂(CN₂). The structure of Sc₂(CN₂)₃ is isotypic to the well-known rare earth carbodiimides RE₂(CN₂)₃ with the smaller cations RE = Tm, Yb, and Lu, whereas Sc₂O₂(CN₂) is not isotypic to the known RE₂O₂(CN₂) (RE = Y, La, Ce–Gd, except Pm) compounds. Both crystal structures are represented by layered arrangements of scandium, respectively scandium and oxide, alternating with carbodiimide layers.     

Synthesis and Structure of the New Compound La2O(CN2)2 Possessing an Interchanged Anion Proportion Compared to the Parent La2O2(CN2). Synthese und Kristallstruktur der neuen Verbindung La2O(CN2)2 mit einem vertauschten Anionenverhältnis gegenüber der Bezugsverbindung La2O2(CN2)

La₂O(CN₂)₂ was synthesized from a 1:1:2 molar reaction mixture of LaCl₃, LaOCl, and Li₂(CN₂) at 650 °C. Well developed single crystals were grown from a LiCl‐KCl flux. The crystal structure was refined as monoclinic (space group C2/c, Z = 2, a = 13.530(2) Å, b = 6.250(1) Å, c = 6.1017(9) Å, β = 104.81(2)°) from single crystal X‐ray diffraction data. The La³⁺ and (CN₂)^2— ions in the crystal structure of La₂O(CN₂)₂ can be compared to Fe³⁺ and S₂^2— ions in the cubic pyrite structure, being arranged like in a distorted NaCl type structure with their centers of gravity. In addition, the O^2— ions in La₂O(CN₂)₂ are occupying 1/4 of the tetrahedral voids formed by the arrangement of metal ions.     

Die Reaktionen von Europium und Yttrium mit N‐Iod‐triphenylphosphanimin. Kristallstrukturen von [EuI2(DME)3], [Eu2I(NPPh3)5(DME)] und [Y2I(NPPh3)4(THF)4]+I3–

The Reactions of Europium and Yttrium with N‐Iodinetriphenylphosphoraneimine. Crystal Structures of [EuI₂(DME)₃], [Eu₂I(NPPh₃)₅(DME)] and [Y₂I(NPPh₃)₄(THF)₄]⁺I₃^– When treated with ultrasound, the reaction of europium metal with INPPh₃ in 1,2‐dimethoxyethane (DME) leads to the complexes [EuI₂(DME)₃] ( 1 ) and [Eu₂I(NPPh₃)₅(DME)] ( 2 ) which are separated from each other by fractional crystallization. On the other hand, the reaction of yttrium metal with INPPh₃ under similar conditions in THF gives the ionic phosphoraneiminato complex [Y₂I(NPPh₃)₄(THF)₄]⁺I₃^– ( 3 ). All complexes are characterized by crystal structure determinations. 1 : Space group P2₁, Z = 2, lattice dimensions at 188 K: a = 848.9(1); b = 1059.4(1); c = 1227.9(1) pm; β = 93.793(6)°; R = 0.0246. In the molecular structure of 1 the europium atom is eightfold coordinated with a bond angle I–Eu–I of 158.51°. 2 · 2 DME: Space group P1, Z = 2, lattice dimensions at 193 K: a = 1405.5(1); b = 1652.2(2); c = 2203.7(2) pm; α = 89.404(11)°; β = 72.958(11)°; γ = 78.657(11)°; R = 0.0391. In 2 the europium atoms are linked by the μ‐N‐atoms of two (NPPh₃^–) groups to form a planar Eu₂N₂ four‐membered ring. One of the Eu atoms is terminally coordinated by the N atoms of two (NPPh₃^–) groups, thus achieving a distorted tetrahedral surrounding. The second Eu atom is coordinated by the N atom of one (NPPh₃^–) group, by the terminally bounded iodine atom and by the oxygen atoms of the DME chelate, thus achieving a distorted octahedral surrounding. 3 · 6¹/₂ THF: Space group P1, Z = 2, lattice dimensions at 103 K: a = 1739.7(2); b = 1770.1(2); c = 2153.8(3) pm; α = 74.929(15)°; β = 84.223(14)°; γ = 64.612(12)°; R = 0.0638. In the cation [Y₂I(NPPh₃)₄(THF)₄]⁺ of 3 the yttrium atoms are linked by the μ‐N atoms of two (NPPh₃^–) groups as well as by the μ‐I atom. One (NPPh₃^–) ligand and two THF molecules complete the distorted octahedral coordination at each yttrium atom.     

The New Homoleptic Tetracyanamidoaluminate LiBa2[Al(CN2)4]

The new tetracyanamidoaluminate LiBa₂[Al(CN₂)₄] was prepared by solid state metathesis reaction in a fused copper ampoule from a mixture of BaF₂, AlF₃, and Li₂(CN₂) at 550 °C. The crystal structure was solved and refined based on single‐crystal X‐ray diffraction data [P2₁2₁2₁, Z = 4, a = 6.843(1) Å, b = 11.828(2) Å, c = 11.857(2) Å]. The compound belongs to the known formula type LiM₂[Al(CN₂)₄] (M = Sr, Eu) containing the homoleptic [Al(CN₂)₄]^5– ion. However, LiBa₂[Al(CN₂)₄] forms a distinct crystal structure, containing a two‐dimensional [(NCN)_2/2Li(NCN)₂Al(NCN)_2/2] network with four‐coordinate Li⁺ and Al³⁺ ions. Two crystallographically independent Ba²⁺ ions are situated in eightfold environment of terminal nitrogen atoms of cyanamide ions.     

ChemInform Abstract: Refined Crystal Structure and Idealized Structure of Mixed‐Valent Eu4F5(CN2)2: Transition Possible.

The title compound is prepared by solid state reaction of EuF₃, EuF_2+x, and Li₂(CN₂) at 700 °C and characterized by single crystal XRD, ¹⁵¹Eu Moessbauer spectroscopy, and magnetic measurements.     

Phosphaniminato‐Acetato‐Cluster von Kupfer und Zink. Kristallstrukturen von [Cu4(NPEt3)2(O2CCH3)6] und [Zn4(NPEt3)2(O2CCH3)6]

Phosphoraneiminato Acetate Cluster of Copper and Zinc. Crystal Structures of [Cu₄(NPEt₃)₂(O₂CCH₃)₆] and [Zn₄(NPEt₃)₂(O₂CCH₃)₆] The anhydrous acetates of copper(II) and zinc react with the silylated phosphaneimine Me₃SiNPEt₃ in dichloromethane at 20 °C forming the mixed phosphoraneiminato acetate clusters [Cu₄(NPEt₃)₂(O₂CCH₃)₆] ( 1 ), which forms emerald crystals, and colourless [Zn₄(NPEt₃)₂ · (O₂CCH₃)₆] ( 2 ). In spite of analogous composition the structures of 1 and 2 are completely different. In the asymmetric unit of 1 three copper atoms of an almost isosceles triangle are linked via two nitrogen atoms of the NPEt₃^– groups to form a trigonal bipyramidal aggregate. One of these three copper atoms is chelated by an acetate group, another one is connected with the fourth copper atom via three μ₂‐O₂C–CH₃ groups. The asymmetric units are associated via a μ₂‐O₂C–CH₃ group and a μ₃‐OC(O)CH₃ group at a time so that infinite chains result. In 2 two zinc atoms are linked via the nitrogen atoms of the two NPEt₃^– groups to form an almost centrosymmetric four‐membered ring. Both nitrogen atoms of the four‐membered ring are connected with another zinc atom each. These zinc atoms again are linked with the zinc atoms of the Zn₂N₂ four‐membered ring via two μ₂‐O₂C–CH₃ groups each and additionally coordinated with a terminal acetate ligand each.     

Rare Earth Carbodiimide Silicates: RE2(CN2)(SiO4)

Rare earth carbodiimide silicates RE₂(CN₂)(SiO₄) with RE = Y, La, and Pr were synthesised by solid state metathesis reactions of RECl₃, Li₂(CN₂), and SiO₂ or Li₂SiO₄, respectively, in silica tubes at 550 °C. All three compounds crystallise with different structures, although all of them represent distorted derivatives of the sodium chloride type structure. The structure of Y₂(CN₂)(SiO₄) was refined monoclinically (C2/m, Z = 2, a = 1301.382(5) pm, b = 377.630(1) pm, c = 527.656(2) pm, β = 93.9816(2) °) from X‐ray powder data. The crystal structure of La₂(CN₂)(SiO₄) was refined in a different monoclinic space group (P2₁/c, Z = 4, a = 660.3(1) pm, b = 1282.0(2) pm, c = 656.2(1) pm, β = 105.23(2) °), and the structure of Pr₂(CN₂)(SiO₄) was refined triclinically (P\bar{1} , Z = 2, a = 646.7(2) pm, b = 669.2(2) pm, c = 671.8(2) pm, α = 86.18(3) °, β = 73.22(3) °, γ = 74.08(3) °) from X‐ray single crystal data.     

Ba2(CN2)(CN)2 und Sr2(CN2)(CN)2 – die ersten gemischten Cyanamid-cyanide

Ba₂(CN₂)(CN)₂ and Sr₂(CN₂)(CN)₂ – the First mixed Cyanamide Cyanides The mixed cyanamide-cyanides M₂(CN₂)(CN)₂ (M = Ba, Sr) were synthesized by the reaction of Ba₂N and SrCO₃, respectively, with HCN at 630°C. The crystal structure of Ba₂(CN₂)(CN)₂ was determined from single-crystal X-ray investigations at room temperature and ?100°C; the isostructural Sr₂(CN₂)(CN)₂ was refined using powder methods (P6₃/mmc; Ba₂(CN₂)(CN)₂: a = 1 066.52(5) pm, c=696.82(3) pm; Sr₂(CN₂)(CN)₂: a = 1 035.91(1) pm, c = 664.23(1) pm; Z = 4). The crystal structure is a partially filled defect variant of the anti-NiAs structure type with a distorted hexagonal close packed arrangement of M²⁺-ions. All CN₂^2? and one quarter of the CN^? ions occupy 3/4 of the octahedrally coordinated interstices, the remaining cyanide anions are located at 3/8 of the tetrahedral sites. In the crystal structure the CN^? are coordinated to the cations both end-on and side-on. All anions can be distinguished by vibrational spectroscopy.     

Two Heteroleptic Zinc(II) Complexes: [Zn(phen)(C9H15O6)2] and [Zn2(phen)2(H2O)2(C10H16O4)2] · 3H2O

Reactions of a freshly prepared Zn(OH)_2‐2x(CO₃)x · yH₂O precipitate, phenanthroline with azelaic and sebacic acid in CH₃OH/H₂O afforded [Zn(phen)(C₉H₁₅O₄)₂] ( 1 ) and [Zn₂(phen)₂(H₂O)₂(C₁₀H₁₆O₄)₂] · 3H₂O ( 2 ), respectively. They were structurally characterized by X‐ray diffraction methods. Compound 1 consists of complex molecules [Zn(phen)(C₉H₁₅O₄)₂] in which the Zn atoms are tetrahedrally coordinated by two N atoms of one phen ligand and two O atoms of different monodentate hydrogen azelaato groups. Intermolecular C(alkyl)‐H···π interactions and the intermolecular C(aryl)‐H···O and O‐H···O hydrogen bonds are responsible for the supramolecular assembly of the [Zn(phen)(C₉H₁₅O₄)₂] complexes. Compound 2 is built up from crystal H₂O molecules and the centrosymmetric binuclear [Zn₂(phen)₂(H₂O)₂(C₁₀H₁₆O₄)₂] complex, in which two [Zn(phen)(H₂O)]²⁺ moieties are bridged by two sebacato ligands. Through the intermolecular C(alkyl)‐H···O hydrogen bonds and π‐π stacking interactions, the binuclear complex molecules are assembled into layers, between which the lattice H₂O molecules are sandwiched. Crystal data: ( 1 ) C2/c (no. 15), a = 13.887(2), b = 9.790(2), c = 22.887(3)Å, β = 107.05(1)°, U = 2974.8(8)ų, Z = 4; ( 2 ) P1¯ (no. 2), a = 8.414(1), b = 10.679(1), c = 14.076(2)Å, α = 106.52(1)°, β = 91.56(1)°, γ = 99.09(1)°, U = 1193.9(2)ų, Z = 1.     

[Co7(μ4‐O)2(O2C–CH3)8(NCO)2(HNPEt3)4] · 2 OEt2, ein siebenkerniger Komplex mit vier‐, fünf‐ und sechsfach koordinierten Cobalt‐Atomen

[Co₇(μ₄‐O)₂(O₂C–CH₃)₈(NCO)₂(HNPEt₃)₄] · 2 OEt₂, a Seven Nuclearity Complex with Four, Five, and Sixfold Coordinated Cobalt Atoms The title compound was prepared from cobalt(II) acetate with Me₃SiNPEt₃ at 180 °C and subsequent crystallization from diethylether to give blue, moisture sensitive single crystals, which were characterized by a crystal structure determination. Space group P2₁/n, Z = 2, lattice dimensions at –80 °C: a = 1544.0(1), b = 1522.1(2), c = 1702.0(1) pm, β = 103.911(10)°, R = 0.0490. [Co₇(μ₄‐O)₂(O₂C–CH₃)₈(NCO)₂ · (HNPEt₃)₄] has a centrosymmetric cluster‐like structure in which the octahedrally coordinated central cobalt atom is connected with the remaining six cobalt atoms via two μ₄‐oxygen atoms as well as via four bridging acetato groups to form a Co(Co)₆ octahedral skeleton. Four of the peripheric cobalt atoms have a distorted trigonal‐bipyramidal coordination sphere, the other two cobalt atoms are tetrahedrally coordinated. The latter are connected with the nitrogen atoms of the cyanato groups.     

Phosphaniminato-Komplexe des Schwefels. Synthese und Kristallstrukturen von [O3SS(NPPh3)2] · CH3CN, [SO(NPPh3)2] und [SCl(NPMe3)2]Cl

Phosphorane Iminato Complexes of Sulfur. Syntheses and Crystal Structures of [O₃SS(NPPh₃)₂] · CH₃CN, [SO(NPPh₃)₂], and [SCl(NPMe₃)₂]Cl The title compounds have been prepared by the reaction of Me₃SiNPPh₃ with SO₂ and SOCl₂, respectively, and by the reaction of Me₃SiNPMe₃ with S₂Cl₂. They form colourless, moisture sensitive crystals, which were characterized by IR spectroscopy and by crystal structure determinations. [O₃SS((NPPh₃)₂)] · CH₃CN : Space group Pca2₁, Z = 4, structure solution with 4016 observed unique reflections, R = 0.050. Lattice dimensions at ?60°C: a = 1865.1, b = 1168.4, c = 1569.0 pm. The compound has a zwitterionic structure with a S? S bond length of 218.2 pm and bond lengths S? N of 161.2 and P? N of 160.1 pm. [SO(NPPh₃)₂] : Space group P2₁/c, Z = 4, structure solution with 2854 observed unique reflections, R = 0.113. Lattice dimensions at ?50°C: a = 1173.1, b = 1585.6, c = 1619.2 pm, b? = 98.13°. The compound forms monomeric molecules, in which the positions of S and N atoms are disordered in two positions. The bond lengths are S? N 166 pm and P? N 163 pm in average. [SCl(NPMe₃)₂]Cl : Space group P1 , Z = 2, structure solution with 2416 observed unique reflections, R = 0.038. Lattice dimensions at 20°C: a = 613.2, b = 1030.3, c = 1111.4 pm, α = 88.48°, b? = 88.01°, γ = 83.10°. The compound forms ions [SCl(NPMe₃)₂]⁺ and Cl^?. In the cation the sulfur atom is ?-tetrahedrally coordinated with a long S? Cl distance of 246.9 pm and bond lengths S? N of 155.3 pm and P? N of 164.3 pm in average.     

Triethylphosphanimin-Komplexe der Acetate von Kupfer(II) und Zink. Kristallstrukturen von [Zn(O2C–CH3)2(HNPEt3)], [Cu5(O2C–CH3)10(HNPEt3)2] und [Cu(O2C–CH3)2(HNPEt3)2]

Triethylphosphanimine Complexes of the Acetates of Copper(II) and Zinc. Crystal Structures of [Zn(O₂C–CH₃)₂(HNPEt₃)], [Cu₅(O₂C–CH₃)₁₀(HNPEt₃)₂], and [Cu(O₂C–CH₃)₂(HNPEt₃)₂] The title compounds originate from the anhydrous acetates of zinc and copper(II) with trimethylsilyl-triethylphosphanimine, Me₃SiNPEt₃, in the presence of water in dichloromethane. They form colourless ( 1 ), bluish-green ( 2 ), and blue ( 3 ), respectively, single crystals, which were characterized by IR spectroscopy and by crystal structure analyses. [Zn(O₂C–CH₃)₂(HNPEt₃)] ( 1 ): Space group P 4 2₁c, Z = 8, lattice dimensions at –83 °C: a = b = 1709.6(2), c = 982.4(1) pm, R = 0.0551. 1 has a polymeric chain structure in which the zinc atoms are μ₂-bridged via the oxygen atoms of one of the two acetato groups, while the second acetato group and the phosphanimine are bonded terminally. [Cu₅(O₂C–CH₃)₁₀(HNPEt₃)₂]( 2 · 4 CH₂Cl₂): Space group P2₁/c, Z = 8, lattice dimensions at –80 °C: a = 1761.18(13), b = 4074.5(2), c = 1733.34(15) pm, β = 91.383(10)°, R = 0.0413. 2 consists of the two structural units [Cu₂(O₂C–CH₃)₄] and [Cu₃(O₂C–CH₃)₆(HNPEt₃)₂], which are connected via two of the acetato groups of the Cu₃-unit along the crystallographic a-axis to form three crystallographically independent polymeric strands. [Cu(O₂C–CH₃)₂(HNPEt₃)₂] ( 3 ): Space group P2₁/n, Z = 2, lattice dimensions at 20 °C: a = 695.49(8), b = 1217.85(10), c = 1380.05(7) pm, β = 96.451(7)°, R = 0.0291. 3 forms monomeric, centrosymmetric molecules with a square planar environment at the Cu atoms.     

Crystal Structures of [Mn2(H2O)4(phen)2(C4H4O4)2] · 2 H2O and [Mn(phen)2(H2O)2][Mn(phen)2(C4H4O4)](C4H4O4) · 7 H2O

Reactions of 1,10‐phenanthroline monohydrate, Na₂C₄H₄O₄ · 6 H₂O and MnSO₄ · H₂O in CH₃OH/H₂O yielded a mixture of [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] · 2 H₂O ( 1 ) and [Mn(phen)₂(H₂O)₂][Mn(phen)₂(C₄H₄O₄)](C₄H₄O₄) · 7 H₂O ( 2 ). The crystal structure of 1 (P1 (no. 2), a = 8.257(1) Å, b = 8.395(1) Å, c = 12.879(2) Å, α = 95.33(1)°, β = 104.56(1)°, γ = 106.76(1)°, V = 814.1(2) ų, Z = 1) consists of the dinuclear [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] molecules and hydrogen bonded H₂O molecules. The centrosymmetric dinuclear molecules, in which the Mn atoms are octahedrally coordinated by two N atoms of one phen ligand and four O atoms from two H₂O molecules and two bis‐monodentate succinato ligands, are assembled via π‐π stacking interactions into 2 D supramolecular layers parallel to (101) (d(Mn–O) = 2.123–2.265 Å, d(Mn–N) = 2.307 Å). The crystal structure of 2 (P1 (no. 2), a = 14.289(2) Å, b = 15.182(2) Å, c = 15.913(2) Å, α = 67.108(7)°, β = 87.27(1)°, γ = 68.216(8)°, V = 2934.2(7) ų, Z = 2) is composed of the [Mn(phen)₂(H₂O)₂]²⁺ cations, [Mn(phen)₂(C₄H₄O₄)] complex molecules, (C₄H₄O₄)^2– anions, and H₂O molecules. The (C₄H₄O₄)^2– anions and H₂O molecules form 3 D hydrogen bonded network and the cations and complex molecules in the tunnels along [001] and [011], respectively, are assembled via the π‐π stacking interactions into 1 D supramolecular chains. The Mn atoms are octahedrally coordinated by four N atoms of two bidentate chelating phen ligands and two water O atoms or two carboxyl O atoms (d(Mn–O) = 2.088–2.129 Å, d(Mn–N) = 2.277–2.355 Å). Interestingly, the succinato ligands in the complex molecules assume gauche conformation bidentately to chelate the Mn atoms into seven‐membered rings.     

ChemInform Abstract: YCa3(CrO)3(BO3)4: A Cr3+ Kagome Lattice Compound Showing No Magnetic Order Down to 2 K.

Polycrystalline gaudefroyite‐type YCa₃(CrO)₃(BO₃)₄ with Cr³⁺ ions (3d³, S = 3/2) forming an undistorted Kagome lattice is prepared by reaction of a stoichiometric mixture of Y₂O₃, CaCO₃, Cr₂O₃, H₃BO₃ in a KCl flux (Al₂O₃ crucible, 1000 °C, 1 d) followed by re‐grinding and further annealing (1000 °C, 2 d, 95% yield).     

Kristallstruktur und Schwingungsspektrum von (H2NPPh3)2[SnCl6]·2CH3CN

Crystal Structure and Vibrational Spectrum of (H₂NPPh₃)₂[SnCl₆]·2CH₃CN Single crystals of (H₂NPPh₃)₂[SnCl₆]·2CH₃CN ( 1 ) were obtained by oxidative addition of tin(II) chloride with N‐chloro‐triphenylphosphanimine in acetonitrile in the presence of water. 1 is characterized by IR and Raman spectroscopy as well as by a single crystal structure determination: Space group , Z = 2, lattice dimensions at 193 K: a = 1029.6(1), b = 1441.0(2), c = 1446.1(2) pm, α = 90.91(1)°, β = 92.21(1)°, γ = 92.98(1)°, R₁ = 0.0332. 1 forms an ionic structure with two different site positions of the [SnCl₆]^2? ions. One of them is surrounded by four N‐hydrogen atoms of four (H₂NPPh₃)⁺ ions, four CH₃CN molecules form N–H···N≡C–CH₃ contacts with the other four N‐hydrogen atoms of the cations. Thus, 1 can be written as [(H₂NPPh₃)₄(CH₃CN)₄(SnCl₆)]²⁺[SnCl₆]^2?.     

Time‐Resolved High and Low Temperature Phase Transitions of the Nanocrystalline Cubic Phase in the Y2O3‐ZrO2 and Fe2O3‐ZrO2 System

The nanocrystalline cubic Phase of zirconia was found to be thermally stabilized by the addition of 2.56 to 17.65 mol % Y₂O₃ (5.0 to 30.0 mol % Y, 95.0 to 70.0 mol % Zr cation content). The cubic phase of yttria stabilized zirconia was prepared by thermal decomposition of the hydroxides at 400°C for 1 hr. 2.56 mol % Y₂O₃‐ZrO₂ was stable up to 800°C in an argon atmosphere. The samples with 4.17 to 17.65 mol % Y₂O₃ were stable to 1200°C and higher. All samples at temperatures between 1450°C to 1700°C were cubic except the sample with 2.56 mol % Y₂O₃ which was tetragonal. The crystallite sizes observed for the cubic phase ranged from 50 to 150 Å at temperatures below 900°C and varied from 600 to 800 nm between 1450°C and 1700°C. Control of furnace atmosphere is the main factor for obtaining the cubic phase of Y‐SZ at higher temperature. Nanocrystalline cubic Fe‐SZ (Iron Stabilized Zirconia) with crystallite sizes from 70 to 137 Å was also prepared at 400°C. It transformed isothermally at temperatures above 800°C to the tetragonal Fe‐SZ and ultimately to the monoclinic phase at 900°C. The addition of up to 30 mol % Fe(III) thermally stabilized the cubic phase above 800°C in argon. Higher mol % resulted in a separation of Fe₂O₃. The nanocrystalline cubic Fe‐SZ containing a minimum 20 mol % Fe (III) was found to have the greatest thermal stability. The particle size was a primary factor in determining cubic or tetragonal formation. The oxidation state of Fe in zirconia remained Fe³⁺. Fe‐SZ lattice parameters and rate of particle growth were observed to decrease with higher iron content. The thermal stability of Fe‐SZ is comparable with that of Ca‐SZ, Mg‐SZ and Mn‐SZ prepared by this method.     

Synthese,Kristallstruktur und Festkörper-NMR-spektroskopische Untersuchungen von K5H(CN2)3

Synthesis, Crystal Structure, and Solid State MAS-NMR Spectroscopic Investigation of K₅H(CN₂)₃ Single phase K₅H(CN₂)₃ was synthesized by reaction of KHCN₂ with metallic potassium in liquid ammonia or by reaction of KNH₂ with melamine C₃N₃(NH₂)₃ at 320 °C, respectively. The crystal structure was determined from X-ray powder and single crystal data: K₅H(CN)₃, space group Im3m, a = 795.68(7) pm, Z = 2, R1 = 0.025, wR2 = 0.0438. In the solid K₅H(CN₂)₃ contains K⁺ and CN₂^2–, the anions exhibit D_∞h symmetry. According to ¹H and ¹³C solid state MAS-NMR investigations, temperature dependent impedance spectroscopy, and FTIR spectroscopy the protons are only loosely bound to the CN₂^2– ions. The proton conductivity shows a sharp increase above 70 °C.     

An Azelaato‐bridged Dinuclear Copper(II) Complex, [Cu2(phen)2(C9H14O4)2] · 6 H2O (phen = 1,10‐phenanthroline)

The title compound [Cu₂(phen)₂(C₉H₁₄O₄)₂] · 6 H₂O was prepared by the reaction of CuCl₂ · 2 H₂O, 1,10‐phenanthroline (phen), azelaic acid and Na₂CO₃ in a CH₃OH/H₂O solution. The crystal structure (monoclinic, C2/c (no. 15), a = 22.346(3), b = 11.862(1), c = 17.989(3) Å, β = 91.71(1)°, Z = 4, R = 0.0473, wR² = 0.1344 for 4279 observed reflections) consists of centrosymmetric dinuclear [Cu₂(phen)₂(C₉H₁₄O₄)₂] complexes and hydrogen bonded H₂O molecules. The Cu atom is square‐planar coordinated by the two N atoms of the chelating phen ligand and two O atoms of different bidentate bridging azelaate groups with d(Cu–N) = 2.053, 2.122(2) Å and d(Cu–O) = 1.948(2), 2.031(2) Å. Two azelaate anions bridge two common Cu atoms via the terminal O atoms (d(C–O) = 1.29(2) Å; d(C–C) = 1.550(4)–1.583(4) Å). Phen ligands of adjacent complexes cover each other at distances of about 3.62 Å, indicating π‐π stacking interaction, by which the complexes are linked to 1 D bands.     

Struktur und thermisches Verhalten von Gadolinium(III)-sulfat-Octahydrat Gd2(SO4)3 · 8 H2O

Structure and Thermal Behaviour of Gadolinium(III)-sulfate-octahydrate Gd₂(SO₄)₃ · 8 H₂O . Gd₂(SO₄)₃ · 8 H₂O crystallizes monoclinic with space group C2/c and the lattice constants a = 13.531(7), b = 6.739(2), c = 18.294(7) Å, β = 102.20(8)°. In the structure Gd is coordinated by 4 oxygen atoms of crystal water and 4 oxygens of sulfate giving rise to a distorted square antiprism. During DTA-TG-experiments the title compound first loses crystal water in a two-step mechanism in the temperature range 130–306°C. The resulting Gd₂(SO₄)₃ is amorphous and recrystallization occurs in the range 380–411°C. The so-obtained low-temperature modification β-Gd₂(SO₄)₃, undergoes a monotropic phase transition at about 750°C to the high-temperature form α-Gd₂(SO₄)₃. The powder pattern of this modification was indexed based on monoclinic symmetry with space group C2/c and lattice constants a = 9.097(3), b = 14.345(5), c = 6.234(2) Å, β = 97.75(8)°. The hightemperature modification of gadolinium-sulfate shows decomposition to Gd₂O₂SO₄ at 900°C and, subsequently, decomposition at 1 200°C yields the formation of C-Gd₂O₃.