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Electron-rich [Fe(CN)4]6− features a π-backbonding scheme with non-innocent CN-ligands exhibiting weak C–N bonds and a d10 configuration on iron.

Transparent dark orange Ba[Au(N3)4]2·4H2O was synthesized by reaction of Ba(N3)2 and AuCl3 or HAuCl4 in aqueous solution. The novel barium tetraazidoaurate(III) tetrahydrate crystallizes in the monoclinic space group Cc (no. 9) with a = 1813.68(17) pm, b = 1737.95(11) pm, c = 682.04(8) pm and β = 108.849(4)°. Predominant structural features of Ba[Au(N3)4]2·4H2O are two crystallographically independent discrete anions [Au(N3)4]- with gold in a tetragonal planar coordination by nitrogen. Vibrational spectra show good agreement with other azidoaurates(III). Upon drying, this salt was shown to be a highly explosive material.

Exceptionally electron‐rich, nearly trigonal‐planar tricyanidometalate anions [Fe(CN)3]7− and [Ru(CN)3]7− were stabilized in LiSr3[Fe(CN)3] and AE3.5[M(CN)3] (AE=Sr, Ba; M=Fe, Ru). They are the first examples of group 8 elements with the oxidation state of −IV. Microcrystalline powders were obtained by a solid‐state route, single crystals from alkali metal flux. While LiSr3[Fe(CN)3] crystallizes in P63/m, the polar space group P63 with three‐fold cell volume for AE3.5[M(CN)3] is confirmed by second harmonic generation. X‐ray diffraction, IR and Raman spectroscopy reveal longer C−N distances (124–128 pm) and much lower stretching frequencies (1484–1634 cm−1) than in classical cyanidometalates. Weak C−N bonds in combination with strong M−C π‐bonding is a scheme also known for carbonylmetalates. Instead of the formal notation [Fe−IV(CN−)3]7−, quantum chemical calculations reveal non‐innocent intermediate‐valent CN1.67− ligands and a closed‐shell d10 configuration for Fe, that is, Fe2−., The electron‐rich cyanidometalates [Fe(CN)3]7− and [Ru(CN)3]7− represent the first examples of group 8 elements with an oxidation state of −IV. DFT calculations reveal a nominal d10s0 configuration, which corresponds to an effective charge of 2−. The high negative charge also weakens the C−N bonds by the population of antibonding states.

The first nitridogermanates(III) Ca6 [Ge2 N6 ] and Sr6 [Ge2 N6 ] were synthesized from sodium flux and structurally characterized by powder and single crystal X-ray diffraction, respectively. They crystallize isostructurally to each other and homeotypic to Ca6 [Cr2 N6 ]H in space group R 3‾ . They feature unprecedented, mutually isolated, ethane-like [GeIII2 N6 ]12- anions in a staggered conformation. The compounds are semiconductors according to resistivity measurements and electronic structure calculations, yielding band gaps of 1.1 eV for Ca6 [Ge2 N6 ] and 0.2 eV for Sr6 [Ge2 N6 ].

${\mathrm{Li}}_{2}\mathrm{Sr}{[\mathrm{MnN}]}_{2}$ single crystals were successfully grown out of Li-rich flux. The crystal structure was determined by single-crystal x-ray diffraction and revealed almost linear $\ensuremath{-}\mathrm{N}\ensuremath{-}\mathrm{Mn}\ensuremath{-}\mathrm{N}\ensuremath{-}\mathrm{Mn}\ensuremath{-}$ chains as central structural motif. Tetragonal blocks of air and moisture-sensitive nitridomanganate were employed for electrical transport, heat capacity, and anisotropic magnetization measurements. Both the electronic and magnetic properties are most remarkable, in particular the linear increase of the magnetic susceptibility with temperature that is reminiscent of underdoped cuprate and Fe-based superconductors. Clear indications for antiferromagnetic ordering at ${T}_{N}=290$ K were obtained. Metallic transport behavior is experimentally observed in accordance with electronic band structure calculations.

The first nitridogermanates(III) Ca6[Ge2N6] and Sr6[Ge2N6] were synthesized from sodium flux and structurally characterized by powder and single crystal X‐ray diffraction, respectively. They crystallize isostructurally to each other and homeotypic to Ca6[Cr2N6]H in space group R 3‾ . They feature unprecedented, mutually isolated, ethane‐like [GeIII 2N6]12− anions in a staggered conformation. The compounds are semiconductors according to resistivity measurements and electronic structure calculations, yielding band gaps of 1.1 eV for Ca6[Ge2N6] and 0.2 eV for Sr6[Ge2N6]., The nitridogermanates(III), Ca6[Ge2N6] and Sr6[Ge2N6], contain the hitherto unknown molecular anion [Ge2N6]12− featuring a Ge−Ge‐bond and thus represent the first members of a novel class of compounds virtually unknown in the nitride chemistry of tetrel elements.

Two new calcium nitridomanganates, Ca12 [Mn19 N23 ] (P3, a=11.81341(3) A, c=5.58975(2) A, Z=1) and Ca133 [Mn216 N260 ] (P3‾ , a=39.477(1) A, c=5.5974(2) A, Z=1), were obtained by a gas-solid reaction of Ca3 N2 and Mn with N2 at 1273 K and 1223 K, respectively. The crystal structure of Ca12 [Mn19 N23 ] was determined from high-resolution X-ray synchrotron powder diffraction data, whereas single-crystal X-ray diffraction was employed to establish the crystal structure of the Ca133 [Mn216 N260 ] phase, which classifies as a complex metallic alloy (CMA). Both crystal structures have 2D nitridomanganate layers containing similar building blocks but of different levels of structural complexity. Bonding analysis as well as magnetic susceptibility and electron spin resonance measurements revealed that only a fraction of the Mn atoms in both structures carries a localized magnetic moment, while for most Mn species the magnetism is quenched as a result of metal-metal bond formation.

Single crystals of the compounds Li2 AeTt (Ae=Ca, Ba, Tt=Si, Ge, Sn, Pb) were grown in reactive lithium melts in sealed tantalum ampoules from an equimolar ratio of the alkaline earth metal and the respective group 4 element. All compounds, with the exception of Li2CaSn and Li2CaPb, are isotypic and crystallize in an orthorhombic unit cell (space group Pmmn, no. 59). The crystal structure can be characterized as superimposed corrugated networks of Li2 Tt connected by calcium or barium atoms within the third dimension. Li2CaSn and Li2CaPb crystallize in the cubic space group Fm3̅m (no. 225) in a Heusler-type (MnCu2Al) structure. According to magnetic susceptibility and electric resistivity measurements, the compounds Li2BaGe, Li2BaSn, and Li2BaPb represent diamagnetic activated semiconductors.

Large single crystals of Li2(Ca3N)2[Ga4] and Li2(Sr3N)2[Ga4] up to several mm in size were grown from mixtures of the respective elements and binary alkaline-earth metal nitrides in reactive lithium melts employing a modified high-temperature centrifugation-aided filtration (HTCAF) technique. The main structural features of these isotypic phases are stella quadrangula building units [Ga4]Li4/2 and octahedra (Nae6/2), which form two independent interpenetrating networks. The phases crystallize in the η-carbide structure and represent diamagnetic small bandgap semiconductors. Real-space chemical bonding analysis indicates predominantly ionic bonding.

Die Groswohnsiedlung Koln-Chorweiler, Vorzeigeobjekt eines inhumanen Stadtebaus, ist gepragt von einem negativen Image, einer identitatslosen Architektur sowie einer mangelhaften Freiraumgestaltung und einseitigen Bevolkerungsstruktur. Das vorgeschlagene Entwicklungskonzept sieht eine Kombination aus Masnahmen auf den Ebenen Stadtebau, Architektur, Mobilitat, Freiraum, Energie und Soziales vor. Das Konzept stellt eine Verbindung zur Natur her, sowohl im okologischen als auch im gestalterischen Sinn. Es wird eine Formensprache angewandt, die zu Stadtraumen fuhrt, in denen sich die Menschen gerne aufhalten, die Moglichkeiten der direkten Begegnung von Mensch zu Mensch bieten, somit Interaktion ermoglichen und dadurch zum Zentrum stadtischen Lebens werden.

We present the synthesis route to carbon with hierarchical morphology on the nanoscale. The structures are generated using crystalline orthorhombic lithium carbide (Li2C2) as precursor with nanolamellar organization. Careful treatment by SnI4 oxidizes carbon at the fairly low temperature of 80 °C to the elemental state and keeps intact the initial crystallite shape, the internal lamellar texture of particles, and the lamellae stacking. The reaction product is amorphous but displays in the microstructure parallel band-like arrangements with diameters in the range of 200–500 nm. These bands exhibit internal fine structure made up by thin strips of about 60 nm width running inclined with respect to the long axis of the band. The stripes of neighboring columns sometimes meet and give rise to arrow-like arrangements in the microstructure. This is an alternative preparation method of nanostructured carbon from an inorganic precursor by a chemical redox route without applying physical methods such as ion implant...

The unprecedented, fully deprotonated form of acetonitrile, the acetonitriletriide anion CCN3−, is experimentally realized for the first time in the stabilizing bulk host framework of the Ba5[TaN4][C2N] nitridometalate via a one-pot synthesis from the elements under moderate conditions (920 K). The molecular structure of this long-sought acetonitrile derivative is confirmed by X-ray diffraction, as well as NMR, IR, and Raman spectroscopy. The anion is isoelectronic to the CO2 molecule, and, in contrast to acetonitrile (H3C−C≡N), the electron pairs are shifted towards two double bonds, that is, [C=C=N]3−.

$\mathrm{Li}{\mathbf{Sr}}_{2}[{\mathrm{CoN}}_{2}]$ single crystals were successfully grown out of Li-rich flux. Temperature- and field-dependent measurements of the magnetization in the range of $T=2--300\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ and up to ${\ensuremath{\mu}}_{0}\mathit{H}=7\phantom{\rule{0.28em}{0ex}}\mathrm{T}$ as well as measurements of the heat capacity are presented. Ferromagnetic ordering emerges below ${T}_{C}=44\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ and comparatively large coercivity fields of ${\ensuremath{\mu}}_{0}H=0.3\phantom{\rule{0.28em}{0ex}}\mathrm{T}$ as well as pronounced anisotropy are observed upon cooling. Polycrystalline samples of the Ca analog $\mathrm{Li}{\mathbf{Ca}}_{2}[{\mathrm{CoN}}_{2}]$ were obtained and investigated in a similar way. In both compounds Co manifests orbital contributions to the magnetic moment and large single-ion anisotropy caused by second-order spin-orbit couplings. Quantum chemistry calculations reveal a magnetic anisotropy energy of 7 meV, twice as large as the values reported for similar Co ${d}^{8}$ systems.

Up to now, investigation of physical properties of ternary and higher nitridometalates was severely hampered by challenges concerning phase purity and crystal size. Employing a modified lithium flux technique, we are now able to prepare sufficiently large single crystals of the highly air and moisture sensitive nitridoferrate $\rm Li_2Sr[Li_{1-x}Fe_xN]_2$ for anisotropic magnetization measurements. The magnetic properties are most remarkable: large anisotropy and coercivity fields of 7 Tesla at $T = 2$ K indicate a significant orbital contribution to the magnetic moment of iron. Altogether, the novel growth method opens a route towards interesting phases in the comparatively recent research field of nitridometalates and should be applicable to various other materials., Comment: 10 pages, 5 figures, published open access in Inorganics, minor typos corrected

Two new calcium nitridomanganates, Ca

The title compound Ca_3[BN_2]I_3 was obtained from reactions of mixtures of the starting materials Ca_3[BN_2]_2 and CaI_2 in a 1:4 ratio in sealed Nb tubes at 1223 K. The crystal structure was solved from powder synchrotron diffraction data. Ca_3[BN_2]I_3 is the first example of a halide-rich nitridoborate crystallizing in the rhombohedral space group R32 [no. 155, Pearson code: hR96; Z = 12; a = 16.70491(2) A, c = 12.41024(2) A]. The crystal structure is built up by two interpenetrating networks of condensed edge-sharing [BN_2]@Ca_6 and [□]@I_6 trigonal antiprisms (□ = void). In Ca_3[BN_2]I_3 two crystallograhically distinct [BN_2]^(3–) anions are present with d(B1–N) = 1.393(2) A and d(B2–N) = 1.369(9) A. Their bond angles are practically linear, varying only slightly: N–B1–N = 179(1)° and N–B2–N = 180°. Vibrational spectra were interpreted based on the D_(∞h) symmetry of the discrete linear [N–B–N]^(3–) moieties, considering the site symmetry reduction and the presence of two distinct [BN_2]^(3–) groups.

Brownish gray microcrystalline powders of Ba3[Rh(CN)3] were synthesized from pellets of mixtures of Ba2N, rhodium, NaCN, and graphite at 1070 K in an argon atmosphere. Synchrotron powder diffraction data at 293(1) K revealed the crystal structure of the compound [P63/m, a = 9.23266(7) A, c = 5.81612(6) A] is isostructural to Ba3[Co(CN)3] and Ba3[Ir(CN)3]. The trigonal-planar complex [Rh(CN)3]6– is surrounded by nine Ba2+ cations forming a tri-capped trigonal prism. Compared to typical cyano ligands, the C–N bond is long [1.21(5) A] and the vibrational frequencies are low (IR 1674 cm–1, Raman 1728 cm–1).

Na3[BN2] and Na2K[BN2] were obtained as white polycrystalline powders from the reaction of the respective binary mixtures NaNH2:NaBH4 and NaNH2:KBH4 in molar ratio 2:1 at 873 K and 683 K, respectively, in an argon stream. According to the results of thermal analysis measurements, both compounds are thermally stable only up to 954 K (Na3[BN2]) and 712 K (Na2K[BN2]), respectively, decomposing under evolution of alkali metal and nitrogen to yield hexagonal BN as final residue, which was identified from powder patterns. The crystal structure of Na3[BN2] {β-Li3[BN2] type; P21/c (No. 14); Z = 4} was confirmed and the unit cell parameters redetermined: a = 5.724(1) A, b = 7.944(1) A, c = 7.893(1) A, β = 111.31(1)°. According to X-ray powder data, Na2K[BN2] crystallizes isotypic to Na2KCuO2 in the tetragonal space group I4/mmm (No. 139) with a = 4.2359(1) A, c = 10.3014(2) A and Z = 2. The crystal structure of Na2K[BN2] is composed of linear [N–B–N]3– anions centering elongated M14 rhombic dodecahedra, which are formed by 8 sodium and 6 potassium atoms. The [BN2]@Na8/4K6/6 polyhedra are stacked along [001] and condensed via common tetragonal faces to generate a space-filling 3D arrangement. The B–N bond lengths for the strictly linear [N–B–N]3– units are 1.357(4) A. Vibrational spectra of the title compounds were measured and analyzed based on D∞h symmetry of the relevant [N–B–N]3– groups taking into account the site symmetry effects for Na3[BN2]. Both the wavenumbers, as well as the calculated valence force constants f(B–N) = 7.29 N·cm–1 (Na3[BN2]) and 7.33 N·cm–1 (Na2K[BN2]), respectively, are in good agreement with those of the known alkali and alkaline earth dinitridoborates.

We present the synthesis route to carbon with hierarchical morphology on the nanoscale. The structures are generated using crystalline orthorhombic lithium carbide (Li

The unprecedented, fully deprotonated form of acetonitrile, the acetonitriletriide anion CCN

Mg2[BN2]Br was prepared from stoichiometric mixtures of the respective binary components Mg3N2, MgBr2 and BN in sealed niobium ampoules placed in evacuated silica tubes at 1473 K. The monoclinic crystal structure (C2/c (no. 15); a = 9.1509(3) A, b = 6.6209(3) A, c = 6.4756(2) A, β = 109.353(3)° and Z = 4) was determined from powder data. The crystal structure is characterized by cationic 32.4.3.4 nets of magnesium and anionic hexagonal closed packed 36 nets of six-connected nodes occupied by [N–B–N]3– units and Br– anions. Both types of planar nets alternate along the [100] direction. The packing of such incoherent nets results in a monoclinic symmetry, which is a compromise for a structure built up from rod-like [N–B–N]3– units and spherical bromine and magnesium atoms. Bond length and bond angle for the [N–B–N]3– unit are d(B–N) = 1.354(2) A and ∠(N–B–N) = 177.1(9)°, respectively., Vibrational spectra were analyzed based on the D∞h symmetry of the relevant [N–B–N]3– moieties, considering the site symmetry splitting. The results are discussed in context with those of the known members of the magnesium dinitridoborate halide series, Mg2[BN2]Cl and Mg8[BN2]5I.

The transparent dark orange compounds Cs2[Pd(N3)4] and Rb2[Pd(N3)4]·2/3H2O are synthesized by reaction of the respective binary alkali metal azides with K2PdCl4 in aqueous solutions. According to single-crystal X-ray diffraction investigations, the novel ternary azidopalladates(II) crystallize in the monoclinic space group P21/c (no. 14) with a = 705.7(2) pm, b = 717.3(2) pm, c = 1125.2(5) pm, β = 104.58(2)°, mP30 for Cs2[Pd(N3)4] and a = 1041.4(1) pm, b = 1292.9(2) pm, c = 1198.7(1) pm, β = 91.93(1)°, mP102 for Rb2[Pd(N3)4]·2/3H2O, respectively. Predominant structural features of both compounds are discrete [PdII(N3)4]2– anions with palladium in a planar coordination by nitrogen, but differing in point group symmetries., The vibrational spectra of the compounds are analyzed based on the idealized point group C4h of the spectroscopically relevant unit, [Pd(N3)4]2– taking into account the site symmetry splitting due to the symmetry reduction in the solid phase.

Sr6[CoN2]2[CN2] was prepared from Sr2N, carbon, cobalt, and NaN3 as nitrogen source. The crystal structure (I4/mmm (no. 139), a = 383.55(10) pm, c = 1237.8(4) pm) represents a Na2[HgO2] type arrangement with both linear [CoIN2]5– and smaller [CN2]2– ions mutually occupying the [HgO2] position.

The title compound Na2[BH4][NH2]≡Na2BNH6 exists in two different modifications: the low-temperature (LT) β- and the high-temperature (HT) α-phase. The HT α-Na2BNH6 is accessible by single heating of the binaries NaNH2 and NaBH4 (molar ratio = 1:1) to the melting point of 492 K for 1 h in evacuated Pyrex ampoules. On longer annealing (T = 342 K, 10 days), the HT α-phase converts completely to the LT β-phase. The β → α transition at 371 K is very fast, but the conversion α → β is quite slow. No further phase formation was detected in the system up to a molar ratio of 5:1 (NaNH2:NaBH4). The cubic α-Na2BNH6 crystallizes in the K3SO4F-type of structure (space group: P m 3 ¯ m , Z = 1) with a = 4.6950(1) A. β-Na2BNH6 crystallizes in orthorhombic symmetry (space group: Pbcm, Z = 4) with a = 6.5384(2) A, b = 6.4960(1) A, c = 9.8512(2) A. Both structures can directly be derived from the perovskite type structure ABO3, with the [BH4]− and [NH2]− moieties in the A and B sites, respectively. The charge balancing Na ions are occupying 2/3 of the O positions. In both cases, the presence of the two different anions in the solids was also confirmed by vibrational spectra. According to DTA and high temperature X-ray diffraction (HT-XRD) measurements, the educts NaNH2 and NaBH4 react at 430 K to form α-Na2BNH6 which remains stable until the melting point of 492 K. Between 492 and 573 K, no significant effects were detected in DTA and TG. Above 573 K, however, a sudden decomposition takes place in two steps (659 and 689 K) causing a total mass loss of 8%. The gaseous species formed during the decomposition process were followed by mass spectra (MS). The mass spectra obtained from 1:1 and 2:1 mixtures of NaNH2 and NaBH4 in the range 492 K The vibrational spectra of the title compounds Na2BNH6 have been measured and interpreted based on the Td and C2v symmetry of the relevant [BH4]− and [NH2]− groups. Both the (N–H) and (B–H) frequencies exhibit small but significant shifts with respect to the pure binaries.

Spark plasma sintering (SPS) synthesis of CoSb3 and LaFe4Sb12 from ball-milled elemental metal powders has been performed obtaining samples with high relative densities (� 99%). Fracture behaviour, the microstructure and mechanical properties were studied. From ultrasound and nano-indentation measurements, Young’s moduli of 148 GPa for CoSb3 and 141 GPa for LaFe4Sb12 were deduced. SPS has been also applied to compact alkali metal and alkaline-earth metal iron antimonides with filled skutterudite structure. r 2007 NIMS and Elsevier Ltd. All rights reserved.

The first nitridocobaltate carbodiimide (Sr6N)[CoN2][CN2]2 has been synthesized from the elements Sr, Co, and graphite powder and NaN3 (as a nitrogen source). The crystal structure was determined from X-ray single-crystal diffraction data as orthorhombic (space group P21212, No. 18, a=9.8807(6) A, b=14.6474(9) A, c=3.8569(3) A, V=558.2 A3, Z=2, R1=0.0265, wR2=0.0383). (Sr6N)[CoN2][CN2]2 is the first low-valency 3d-transition nitridometalate containing additional [CN2]2− groups. The crystal structure can be described as an array of rocksalt-like columns of Sr and N linked via common corners and connected by [N=C=N]2− and [CoIN2]5− units located within structural channels running along [0 0 1]. The magnetic susceptibility follows the Curie–Weiss law with an effective moment of 3.26 μB consistent with two unpaired spins (d8, CoI). The compound is a bad metallic conductor with a resistivity of order 1 mΩ cm at 300 K. Vibrational spectroscopic data support the existence of carbodiimide [N=C=N]2− species. The Co K-edge X-ray absorption spectra (XAS) of Ca5[CoN2]2 and (Sr6N)[CoN2][CN2]2 confirm the presence of CoI within the complex anions.

Ca5N5V, orthorhombic, Pbcm (no. 57), a = 6.0371(3) Å, b = 16.6146(7) Å, c = 6.7815(3) Å, V = 680.21(5) Å3, Z = 4, R(P) = 0.0100, RF(all) = 0.0348, T = 293 K.

The formation of ternary nitridometalates from the elements in the case of the systems Li—Cr, V, Mn—N leads to compounds which contain the transition metals in the highest (VV, CrVI) or a comparably high (MnV) oxidation state. In the corresponding calcium and strontium systems, the transition metals show a lower oxidation state (VIII, CrIII, MnIII). Transition metals with intermediate oxidation states (CrV, MnIV) are present in the quaternary (mixed cation) compounds Li4Sr2[CrN6], Li6Ca2[MnN6], and Li6Sr2[MnN6] (R3¯(#148), a = 585.9(3) pm, c = 1908.6(4) pm, Z = 3), as well as in the solid solution series Li6(Ca1—xSrx)2[MnN6]. Zur Kontrolle der Oxidationsstufen von Ubergangsmetallen (Cr, Mn) in Nitridometallaten und zur Kenntnis der Mischkristallreihe Li6(Ca1-xSrx)[Mn2N6] Bei der Darstellung aus den Elementen liegt in ternaren Nitridometallaten des Vanadiums, Chroms und Mangans das Ubergangsmetall in den Lithiumverbindungen in der hochstmoglichen (VV, CrVI) oder einer hohen Oxidationsstufe (MnV) vor, in den entsprechenden Calcium- und Strontium-Verbindungen in einer niedrigeren (VIII, CrIII, MnIII). In den quaternaren Verbindungen Li4Sr2[CrN6], Li6Ca2[MnN6] und Li6Sr2[MnN6] (R3¯(#148), a = 585.9(3) pm, c = 1908.6(4) pm, Z = 3) sowie der Mischkristallreihe Li6(Ca1—xSrx)2[MnN6] weist das Ubergangsmetall dagegen eine mittlere Oxidationsstufe auf (CrV, MnIV).

Greenish gray microcrystalline powders of Ba3[Ir(CN)3] were prepared from pressed pellets of mixtures of Ba2N, iridium, NaCN, and graphite at 1020 K under inert conditions. Neutron diffraction data at 293 K revealed the crystal structure of the Ir compound (P63/m (no. 176), a = 9.2277(8) A, c = 5.7878(6) A) to be isostructural to Sr3[Co(CN)3] and Ba3[Co(CN)3]. The trigonal-planar complex [Ir3(CN)3]6– is surrounded by nine Ba2+ ions forming a tricapped trigonal prism. Elongated C–N distances and low vibrational frequencies in the highly reduced iridium complex are similar to those observed in the corresponding cobalt compounds.

Sr5[NbN4]N (transparent, red single crystals) was synthesized by reaction of Sr2N with Nb under nitrogen at ambient pressure and 1223 K. The crystal structure was solved and refined in the space group Pbcm (no. 57), Z = 4, with lattice constants a = 646.6(3) pm, b = 1792.5(9) pm, c = 729.8(4) pm, and R = 0.019, wR2 = 0.034. The crystal structure contains both isolated tetrahedra [NbN4]7- as well as chains of corner sharing octahedra 1(Sr4Sr2/2N7+). Strontium is irregularly coordinated by nitrogen (CN = 4 - 6, Sr-N: 252.3(4) - 340.8(3) pm); nitrogen is located in a distorted octahedral environment by strontium and niobium (Nb-N: 194.5(4) - 199.2(2) pm). By formal reduction of the structural building units to their centers a close structural relationship to both the NiAs and the CaSi type structure is evident.

The reinvestigation of the binary system Ba-Ni revealed the existence of Ba2Ni3 in the temperature range 450 °C–800 °C. Single crystals were grown at 700 °C in the presence of excess barium, followed by separation from the melt by use of the high-temperature centrifugation aided filtration technique, HTCAF. At ambient temperature Ba2Ni3 is in a metastable state which slowly transforms to the elements (side-phases of the binary system). The extreme softness and the mechanical instability of the hygroscopic Ba2Ni3 particles prevented a single crystal structure determination. The crystal structure was solved from X-ray powder diffraction data (Pm1 (No. 164), a = 419.97(2) pm, c = 913.32(3) pm) and revealed Ba2Ni3 to be an isotype of Sr2Ni3 which was reported only recently.

Ba16NbsN19 was synthesized by reaction of Ba with Nb under nitrogen at ambient pressure at 1223 K. The refined crystal structure was solved in the space group P1̄ (no. 2), Z = 2, with the lattice constants a = 1099.33(3), b = 1140.41(15), c = 1622.06(6) pm, α = 72.197(2)°, β = 59.949(1)°, γ = 82.243(2)° and R1 = 0.058, wR2 = 0.088. The crystal structure contains both isolated [NbN4]7- as well as dimeric units [Nb2N7 ]11- . Together with the Ba2+ ions the compound has to be regarded as Ba16 [NbN4]3[Nb2N7 ].

Fallbericht: Wir prasentieren den Fall einer 36-jahrigen febrilen Patientin mit unspezifischer Schmerzsymptomatik und Gewichtsverlust. Nach initialer Diagnose eines unklaren Infektgeschehens mit Soorosophagitis, unspezifischer Duodenitis, Prokitis und Leberparenchymschadigung trat unter antibiotischer und symptomatischer Therapie eine weitere klinische Verschlechterung mit Panzytopenie ein. In der Knochenmarksuntersuchung wurde die Diagnose eines reaktiven Hamophagozytosesyndroms gestellt. Trotz maximaler supportiver und spezifischer Therapie verstarb die Patientin. Todesursache waren ein retroperitoneales Hamatom und eine pramortal nicht diagnostizierte invasive Aspergillose. Schlussfolgerung: Das reaktive infektassoziierte Hamophagozytosesyndrom ist eine seltene Differentialdiagnose einer febrilen Panzytopenie mit schlechter Prognose. Bei Fehlen einer gesicherten kausalen Therapie sind die supportive Therapie und maximale Diagnostik zur Detektion einer behandelbaren Grunderkrankung von entscheidender Bedeutung. Eine antimykotische Therapie sollte generell erwogen werden.

The members Ca 5 [CoN 2 ] 2 , Sr 5 [CoN 2 ] 2 and BaCa 4 [CoN 2 ] 2 of the novel isotypic nitridocobaltate series AE 5 [CoN 2 ] 2 ( P 4/ ncc ) containing linear [Co I N 2 ] 5− complexes were synthesized via high-temperature route. On addition of carbon to the reaction mixtures the nitridocobaltate(I) carbodiimides (Sr 6 N)[Co I N 2 ][CN 2 ] 2 ( P 2 1 2 1 2), and Sr 2 [Co I N 2 ] 1− x [CN 2 ] x ( x = 0.27) ≈ Sr 6 [Co I N 2 ] 2 [CN 2 ] ( I 4/ mmm ) are formed. The low-valence states of Co are investigated in detail. X-ray absorption spectroscopy (XAS) data confirm the assigned low oxidation states for Co in all the compounds under consideration. At high temperatures the nitridocobaltates reveal Curie–Weiss paramagnetic behaviour consistent with Co I and d 8 configuration ( S = 1). Electronic structure calculations and magnetic susceptibility data indicate antiferromagnetic interactions in Ca 5 [CoN 2 ] 2 and BaCa 4 [CoN 2 ] 2 .