Ba[CoN]: Ein niedervalentes Nitridocobaltat mit gewinkelten Ketten [CoN2/22−]

Ba[CoN]: A Low-Valency Nitridocobaltate with Angled Chains [CoN_2/2^2?] Ba[CoN] is prepared by reaction of barium and cobalt (molar ratio Ba : Co = 1 : 2.5) in tantalum crucibles at 870°C with flowing nitrogen (1 atm) within a period of 96 h. After cooling down to room temperature (24°C/h) black single crystals of the ternary phase with a platy habit are obtained (orthorhombic, Pnma; a = 959.9(2) pm, b = 2 351.0(3) pm, c = 547.6(2) pm; Z = 20). The crystal structure of Ba[CoN] contains angled (planar) chains [CoN_2/2^2?] which run along the [010]-direction (N? Co? N[°]: 178.5(5), 179.6(6), 180.0; Co? N? Co[°]: 82.9(6), 84.2(5), 177.1(8); Co? N[pm]: 174.6(12), 177.2(12), 181.9(13), 184.3(13), 187.1(12)). Nitrogen is in an octahedral coordination (N Ba₄Co₂) and is arranged in a distorted cubic close packing. Barium occupies one half of the tetrahedral holes (Ba? N[pm]: 274.8(16) ? 308.2(12)). The cis-positions of the Co-atoms at the nitrogen coordination-octahedra cause short Co? Co contacts within the chains [CoN_2/2^2?]. Through this, Co₂-units (Co? Co[pm]: 247.8(4); bridged by nitrogen) and linear Co₃-groups (Co? Co [pm]: 245.5(2); Co? Co? Co[°]: 180.0; bridged by nitrogen) alternate along the chains. The crystal structure of Ba[CoN] is closely related to the Ba[NiN] type structure.     

Zur Insertion in die Lanthanoid–Kohlenstoffbindung Synthese und Struktur von [CpSm(C6H5CH2NNO)]2 und [K(18-Krone-6)CpYb(NCS)2]∞

On the Insertion into the Lanthanide–Carbon Bond. Synthesis and Structure of [Cp Sm(C₆H₅CH₂NNO)]₂ and [K(18-crown-6)Cp Yb(NCS)₂]_∞ The compound [CpSm(CH₂C₆H₅)(thf)] was investigated, regarding its reactions with small molecules. The main subject was to detect an insertion into the Ln–C bond. With N₂O an insertion reaction is observed, yielding the dimer [CpSm(C₆H₅CH₂NNO)]₂ ( 1 ). The structural data of 1 was collected by a single crystal X-Ray diffraction analysis. (Space group P 1, Z = 1, a = 982.8(2) pm, b = 1052.2(2) pm, c = 1383.8(3) pm, α = 89.29(3)°, β = 73.64(3)°, γ = 66.41(3)°). In the dimer, the two Samarium ions are linked via an (η¹ : η²) bridge by two benzyl diazotato ligands. A nearly planar six-membered central Sm₂N₂O₂-ring is formend. Two pentamethylcyclopentadienyl ligands complete the coordination sphere of each Samarium ion, which are thus surrounded by four ligands each and have a distorted tetrahedral coordination geometry. An insertion of a SCN^– fragment in the Ln–C bond could not be observed. The substitution of the benzyl ligand leads to a polymeric chain structure. The new compound [K(18-crown-6)CpYb(NCS)₂]_∞ 2 contains a tetrahedrally coordinated Yb(III)-ion. (Space group P2₁/n}, Z = 4, a = 1640.6(3) pm, b = 1482.2(3) pm, c = 1674.5(3) pm, β = 102.82(1)°).     

Zur Struktur der basischen Diquecksilber(I)-nitrate. I kristallstruktur des Hg2OH(NO3) · Hg2(NO3)2

The Crystal Structure of the Basic Dimercury (I) Nitrates. I. The Crystal Structure of Hg₂OH(NO₃) · Hg₂(NO₃)₂ The unit cell of Hg₂OH(NO₃) · Hg₂(NO₃)₂ is orthorhombic, space group Cc2a - standard setting Aba2 (C) — with a = 2017.1(5) pm, b = 935.8(3) pm, c = 1121.7(3) pm and contains 8 formula units. Characteristic are chains [Hg₂OH(Hg₂)_2/2]³⁺ parallel [001]. These are interconnected to a three-dimensional network by nitrate ions coordinated to mercury. The structure achieves additional stabilization through weak hydrogen bonds between oxygen atoms of the hydroxy groups and neighbouring nitrate ions. The bonding relationship of one hydrogen atom to four tetrahedrally correlated oxygen atoms is discussed.     

L'action de l'ammoniac sur l'oxyde cuivrique. et les hydroxo-complexes de cuivre (II)

Using a new mathematical treatment, the nature and stability constants of the simple and mixed complex-species of copper(II) with hydroxyde and ammonia as ligands have been determined. The solubility curves of CuO in heterogeneous equilibrium have been identified in function of pH only and in function of pH and pNH_3tot at 25° and unit ionic strength (NaClO₄). The predominent species in the relatively dilute system limited by the ionic strength are [Cu²⁺], [Cu(OH)₂], [Cu(OH)], [Cu(OH)], [Cu(NH₃)], [Cu(NH₃)], [Cu(NH₃)], [Cu(NH₃) (OH)⁺], [Cu(NH₃)₃(OH)⁺] and [Cu(NH₃)₂(OH)₂].     

Zur Chemie und Strukturchemie der Phosphide und Polyphosphide. 27. Bariumdecaphosphid BaP10

Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 27. Bariumdecaphosphide BaP₁₀ Black, reflective crystals of BaP₁₀ are formed by the reaction of BaP₃ with red phosphorus at 1 050 K. The absorption edge at 765 nm corresponds to a band gap of 1.62 eV. The compound is resistant to both acids and bases. The thermal decomposition to Ba₃P₁₄ and then to BaP₃ and other lower phosphides occurs at 725 K. BaP₁₀ crystallizes in the orthorhombic space group Cmc2₁ (No. 36) with 4 formula units (a = 645.2(1), b = 1 258.9(2), c = 1 192.7(2) pm). The structure (632 reflections hkl; R = 0.019) contains the 2-dimensional infinite polyanion [P₁₀^2?], which also characterizes the structure of TlP₅. It originates through the connection of 1-dimensional pentagonal phosphorus tubes, which corresponds to those in the structure of Hittorf's phosphorus and KP₁₅ (bond lengths P? P = 215.0–224.5 pm). Ba is coordinated by 12 P-atoms with distances of 332.7 pm to 374.3 pm.     

Hydroxoverbindungen. 12. Kristallstruktur und Konstitution von Natrium-trihydroxozinkat Na[Zn(OH)3] bei 190 K

Hydroxo Compounds. 12. Crystal Structure and Constitution of Sodium Trihydroxozincate Na[Zn(OH)₃] 1 The crystal structure of the very sensitive sodium trihydroxozincate Na[Zn(OH)₃] 1 has been determined at 190 K. Contrary to the observations of trigonal planar [Zn(OH)₃]^? anions at 298 K, the structure of 1 at lower temperatures is characterized by 1-dimensional chains [Zn(OH)₂(OH)_2/2]^? with the much more plausible (distorted) tetrahedral coordination of the Zn atoms (P4₂bc? C_4v ⁶; Nr. 106; a = 1083.9 pm; c = 530.8 pm; Z = 8; Zn? O = 194.3–200.5 pm). The H positions were determined unambigeously from the X-ray data in complete agreement with calculations of potential profiles. There are pronounced hydrogen bond distances present. The Na atoms are coordinated by (5+1) oxygen atoms (Na? O = 234.8–248.8 pm and 282.7 pm). The noncentric coordination of the atoms as well as the strong anisotropic and anharmonic temperature tensors indicate a second order phase transition between 190 K and 298 K.     

Synthese von Kupfer- und Silberkomplexen mit fünfzähnigen N,S- und sechszähnigen N,O-Chelatliganden – Charakterisierung und Kristallstrukturen von {Cu2[C6H4(SO2)NC(O)]2(C5H5N)4}, {Cu2[C5H3N(CHNC6H4SCH3)2]2}(PF6)2 und {Ag[C5H3N(CHNC6H4SCH3)2]}PO2F2

Synthesis of Copper and Silver Complexes with Pentadentate N,S and Hexadentate N,O Chelate Ligands – Characterization and Crystal Structures of {Cu₂[C₆H₄(SO₂)NC(O)]₂(C₅H₅N)₄}, {Cu₂[C₅H₃N(CHNC₆H₄SCH₃)₂]₂}(PF₆)₂, and {Ag[C₅H₃N(CHNC₆H₄SCH₃)₂]}PO₂F₂ In the course of the reaction of copper(II)-acetate monohydrate with 2,2′-bisbenzo[d][1,3]thiazolidyl in methanol the organic component is transformed to N,N′-bis-(2-thiophenyl)ethanediimine and subsequently oxidized to the N,N′-bis-(2-benzenesulfonyl)ethanediaciddiamide H₄BBSED, which coordinates in its deprotonated form two Cu²⁺ ions. Crystallisation from pyridine/n-hexane yields [Cu₂(BBSED)(py)₄] · MeOH. It forms triclinic crystals with the space group P1 and a = 995.5(2) pm, b = 1076.1(3) pm, c = 1120.7(2) pm, α = 104.17(1)°, β = 105.28(1)°, γ = 113.10(1)° and Z = 1. In the centrosymmetrical dinuclear complex the copper ions are coordinated in a square-pyramidal arrangement by three nitrogen and two oxygen atoms. The Jahn-Teller effect causes an elongation of the axial bond by approximately 30 pm. The reactions of the pentadentate ligand 2,6-Bis-[(2- methylthiophenyl)-2-azaethenyl]pyridine BMTEP with salts of copper(I), copper(II) and silver(I) yield the complexes [CU₂(BMTEP)₂](PF₆)₂, [Cu(BMTEP)]X₂ (X = BF, C1O) and [Ag(BMTEP)]X (X = PO₂F, ClO). [Cu₂(BMTEP)₂](PF₆)₂ crystallizes from acetone/diisopropyl- ether in form of monoclinic crystals with the space group C2/c, and a = 1833.2(3) pm, b = 2267.30(14) pm, c = 1323.5(2) pm, β= 118.286(5)°, and 2 = 4. In the dinuclear complex cation with the symmetry C₂ the copper ions are tetrahedrally coordinated by two bridging BMTEP ligands. The Cu? Cu distance of 278.3pm can be interpreted with weak Cu? Cu interactions which also manifest itself in a temperature independent paramagnetism of 0.45 B.M. The monomeric silver complex [Ag(BMTEP)]PO₂F₂ crystallizes from acetone/thf in the triclinic space group P1 with a = 768.7(3) pm, b = 1074.0(5) pm, c = 1356.8(5) pm, α = 99.52(2)°, β = 96.83(2)°, γ = 99.83(2)° and Z = 2. The central silver ion is coordinated by one sulfur and three nitrogen atoms of the ligand in a planar, semicircular arrangement. The bond lengths Ag? N = 240.4–261.7 and Ag? S = 257.2 pm are significantly elongated in comparison with single bonds.     

RbFe[BP2O8(OH)]: Ein neues Borophosphat mit offen-verzweigten Vierer-Einfach-Tetraederketten

RbFe[BP₂O₈(OH)]: A New Borophosphate Containing Open-Branched Tetrahedral Vierer-Einfach Chains RbFe[BP₂O₈(OH)] is formed under mild hydrothermal conditions (T = 165–170 °C) from a mixture of RbOH_(aq), FeCl₂ · 4 H₂O, H₃BO₃ and H₃PO₄. The crystal structure of the monoclinic compound was solved by x-ray single crystal methods (space group P2₁/c, No. 14): a = 935.8(5) pm, b = 833.9(6) pm, c = 965.6(5) pm; β = 101.69(4)°; Z = 4. The anionic partial structure contains open-branched vierer-einfach chains [BP₂O₈(OH)]^4–, which are formed by alternating borate and phosphate tetrahedra sharing common corners. Fe³⁺ is in an octahedral coordination (FeO₅(OH)), while Rb⁺ is irregularly coordinated by ten oxygen-functions of neighbouring tetrahedra.     

Zur Chemie und Strukturchemie der Phosphide und Polyphosphide. 26. Dibariumheptaphosphidchlorid Ba2P7Cl,eine Verbindung mit dem polycyclischen Anion P

Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 26. Dibariumheptaphosphidechloride Ba₂P₇Cl, a Compound with the Polycyclic Anion P Ba₂P₇Cl is formed by the synthesis of Ba₃P₁₄ from the elements in a melt of BaCl₂ (dehydrated) at 1170 K. The compound forms light rubyred platelets which decompose in protic systems immediately to phosphanes. Ba₂P₇Cl crystallizes in the space group P2₁/m with Z = 2 formular units (a = 1172.6(2) pm; b = 682.9(1) pm; c = 633.7(1) pm; β = 95.27(2)°). The structure (964 reflexions hkl, R = 0.035) is related to the NaCl type, in which the half of the anionic positions is occupied by the gravi-centers of the polycyclic anions P. The bond lengths d(P? P) show the typical topological dependence for the anionic heptaphosphanortricyclene system: (d : 226.4 pm in the three-membered ring; 214.5 pm ring to bridge; 217.2 pm bridge to bridge head). The Ba atoms are surrounded by 9 and 10 non metallic atoms, respectively. Cl^? is coordinated tetrahedrally by Ba.     

Über grünes Bis-(2-Iminoisopropyl-thiophenolato)-nickel(II) und weitere, ähnliche NiII-Komplexe

Green Bis-(2-iminoisopropyl-thiophenolato)nickel(II) and other Similar Ni^II Complexes The compounds [Ni^II(iitp)₂] 1 (iitp = 2-iminoisopropyl-thiophenolate), [Ni(imptp)₂] · 2 CH₃OH 2 , a dinuclear compound with an Ni? Ni distance of 276 pm, and [PPh₄] · [Ni^II(imptp)(SCN)] 3 (imptp = 2-(2-iminopentane-4-on)-thiophenolate) have been prepared by the reaction of nickel(II)-acetate-tetrahydrate with 2-iminoisopropyl-thiophenole and 2-(2-iminopentane-4-on)-thiophenole in methanol, respectively. They have been characterized by single-crystal X-ray structure analysis and other physical methods. The redox behaviour of 1–3 has been studied in detail (chemically as well as by cyclovoltammetry and ESR spectroscopy). Particularly interesting are the electronic properties of 1 and its reduction with NaBH₄ and the following reaction of the product with O₂. The complexes are model compounds for some Ni-containing enzymes. For details of the crystal structure determination see “Inhaltsübersicht”.     

Einkristalluntersuchungen an Fluoroperowskiten MPdF3 (M = Rb,K) und PdF2

Single Crystal Investigations on Fluoroperovskites MPdF₃ (M = Rb, K) and PdF₂ Single crystal investigations on PdF₂ (violet) confirm the tetragonale rutile structure [1, 2] with a = 495.44(3) pm, c = 338.48(3) pm, Z = 2, space group P4₂/mnm-D (No. 136) (x_F = 0.3058(8)). RbPdF₃ and KPdF₃ have been obtained. RbPdF₃ and KPdF₃ both ruby-red single crystals crystallize cubic (perovskite-structure), space group Pm3m-O (No. 221) with a = 429.41(8) pm (RbPdF₃) respectively a = 424.30(4) pm (KPdF₃).     

Das Kupfer(II)‐indium‐oxidphosphat CuInOPO4 mit α‐Fe2OPO4‐Struktur,dargestellt durch die Oxidation einer Cu/In/P‐Legierung im Sauerstoffstrom

The Copper(II) Indium Oxide Phosphate CuInOPO₄ with α‐Fe₂OPO₄ Structure, prepared by Oxidation of a Cu/In/P Alloy with Oxygen Green single crystals of CuInOPO₄ (orthorhombic, Pnma, a = 774.5(1) pm, b = 661.0(1) pm, c = 730.6(1) pm, Z = 4) were prepared by reaction of Cu/In/P‐alloys with oxygen. The compound is isotypic with α‐Fe₂OPO₄. The structure contains isolated [CuO_4/2O₂]‐chains running along [010] formed by CuO₆‐octahedra which are connected by common edges. The chains are linked by phosphate groups and by [InO₄O_2/2]‐chains along [100] consisting of trans vertex connected InO₆‐octahedra.     

Zur Kristallstruktur von MnF3 und MnPtF6

On the Crystal Structure of MnF₃ and MnPtF₆ Single crystal investigations of MnF₃ (rubyred) confirmed the crystal structure based on powder data [2]: monoclinic, space group C 2/c?C (No. 15) with a = 892.02 pm, b = 504.72 pm, c = 1 347.48 pm, β = 92.64° with Z = 12. The corresponding determination of the crystal structure of MnPtF₆, yellow, confirmed the unit cell [3] with a = 510.47 pm, c = 1 421.0 pm and γ = 120°, Z = 3 space group R 3 -C (No. 148). For both compounds detailed parameters respectively interatomic distances have been obtained.     

Darstellung und Struktur der Tetrafluoroaurate(III) MI[AuF4] mit MI = Li,Rb

Synthesis and Structure of Tetrafluoroaurates(III) M^I[AuF₄] with M^I = Li, Rb Single crystal investigations on Rb[AuF₄], light yellow, confirm the tetragonal unit cell (K[BrF₄]-type) with a = 618.2(1) and c = 1191(1) pm, Z = 4, space group I 4/mcm-D (No. 140). Li[AuF₄], light yellow too, crystallizes monoclinic with a = 485.32(7), b = 634.29(8), c = 1004.43(13) pm, β = 92.759(12), Z = 4; space group P 2/c-C (No. 13). The structure of Li[AuF₄] is related to the Rb[AuF₄]-type of structure.     

Ag2+ in trigonal-bipyramidaler Umgebung: Neue Fluoride mit zweiwertigem Silber: AgMMF20 (MII = Cd,Ca, Hg; MIV = Zr,Hf)

Ag²⁺ in Trigonal-Bipyramidal Surrounding New Fluorides with Divalent Silver AgM M F₂₀ (M^II = Cd, Ca, Hg; M^IV = Zr, Hf) The intensively green compounds AgMMMF₂₀ (M^II = Cd, Ca, Hg; M^IV = Zr, Hf) have been obtained for the first time as single crystals and investigated by X-ray methods. They crystallize in space group P6₃/m-C_6h² (Nr. 176) with

• a = 1052.0(2) pm, c = 828.6(2) pm (AgCd₃Zr₃F₂₀),
• a = 1048.0(2) pm, c = 832.6(3) pm (AgCd₃Hf₃F₂₀),
• a = 1059.4(2) pm, c = 841.0(3) pm (AgCa₃Zr₃F₂₀),
• a = 1053.7(2) pm, c = 830.6(3) pm (AgCa₃Hf₃F₂₀),
• a = 1058.9(3) pm, c = 832.6(4) pm (AgHg₃Zr₃F₂₀),
• a = 1056.9(2) pm, c = 833.0(3) pm (AgHg₃Hf₃F₂₀), Z = 2.

     

Synthese und Struktur von (NH4)2[(AuI4)(AuI2(μ2-I4))], einem Iodoaurat(III) mit I-Ionen als Liganden

Synthesis and Structure of (NH₄)₂[(AuI₄)(AuI₂(μ₂-I₄))], a Iodoaurate(III) with I₄^2? Anions as Ligands (NH₄)₂[(AuI₄)(AuI₂(μ₂-I₄))] is obtained in a sealed glass ampoule by slow cooling of a mixture of NH₄I, Au, and I₂ beforehand heated to 500°C. The compound forms black crystals decomposing slowly under loss of I₂. It crystallizes in the orthorhombic space group Pnma with a = 1357.7(1), b = 2169.9(2), c = 755.6(3) pm, and Z = 4. The crystal structure is built up by NH cations and square-planar [AuI₄]^? anions as well as [AuI₂(μ₂-I₄)]^? groups being linked together by the I ligands to form chains. The distances Au? I are in the range of 258.7(2) to 262.4(2) pm. The nearly linear I anions are characterized by a short central I? I distance of 270.9(3) pm and two longer outer distances of 338.7(2) pm.     

Zur Kenntnis komplexer Fluoride mit Cu2+ und Pd2+: MPtF6 (M  Pd,Cu) und RbCuPdF5

On Complex Fluorides with Cu²⁺ and Pd²⁺: MPtF₆ (M ? Pd, Cu) and RbCuPdF₅ For the first time single crystals of PdPtF₆ (green), trigonal-rhomboedric, a = 503.8, c = 1431.6 pm, spcgr. R3 ? C (No. 148), Z = 3, CuPtF₆ (orange), triclinic, a = 495.2, b = 498.5, c = 962.4 pm, α = 89.98, β = 104.23, γ = 120.35°, spcgr. P1 ? C (No. 2), Z = 2 and RbCuPdF₅ (orange brown, in connection with investigations on M^IPd₂F₅ [1]), orthorhombic, a = 626.9, b = 719.9, c = 1076.3 pm, spcgr. Pnma? D (No. 62), Z = 4, four circle diffractometer data, have been obtained.     

Cs4[Sc6C]Cl13 und Cs4[Pr6(C2)]I13 — zwei Beispiele für das fehlende Bindeglied bei der Verknüpfung der Baueinheiten [M6Z]XX

Cs₄[Sc₆C]Cl₁₃ and Cs₄[Pr₆(C₂)]I₁₃ — Two Examples for the Missing Link in the Connectivity of [M₆Z]X X Building Units Cs₄[Sc₆C]Cl₁₃ (tetragonal, I4₁/amd, a = 1 540.5(4), c = 1 017.9(7) pm, c/a = 0.661, Z = 4, R = 0.038, R_w = 0.026) and Cs₄[Pr₆(C₂)]I₁₃ (a = 1 804.9(3), c = 1 259.5(3) pm, c/a = 0.698, R = 0.106, R_w = 0.068) are obtained as green-black and blue-black single crystals with brass-like metallic lustre through metallothermic reduction of ScCl₃ and PrI₃, respectively, with cesium in the presence of carbon in sealed tantalum containers. The, overall, isotypic compounds contain isolated [Sc₆C] and [Pr₆(C₂)] clusters, respectively, that are surrounded by 18 halide (X) ligands (12 Xⁱ and 6 X^a; X = Cl or I). The connection is carried out via the motif [M₆Z]XXXX (M = Sc and Pr; Z = C and C₂, respectively) and is thereby the missing link of the motifs of connection for the composition A_x[M₆Z]X₁₃. Analogous interconnection of [TiO₆] octahedra is found in the anatase-type of structure of TiO₂.     

Rb2Co3(H2O)2[B4P6O24(OH)2]: Ein Borophosphat mit ‐Tetraeder‐Anionenteilstruktur und Oktaeder‐Trimeren (CoO12(H2O)2)

Rb₂Co₃(H₂O)₂[B₄P₆O₂₄(OH)₂]: A Borophosphate with ‐Tetrahedral Anionic Partial Structure and Trimers of Octahedra (Co O₁₂(H₂O)₂) Rb₂Co₃(H₂O)₂[B₄P₆O₂₄(OH)₂] is formed under mild hydrothermal conditions (T = 165 °C) from mixtures of RbOH_(aq), CoCl₂, H₃BO₃, and H₃PO₄ (molar ratio 1 : 1 : 1 : 2). The crystal structure (orthorhombic system) was solved by X‐ray single crystal methods (space group Pbca, No. 61; R‐values (all data): R1 = 0.0699, wR2 = 0.0878): a = 950.1(1) pm, b = 1227.2(2) pm, c = 2007.4(2) pm; Z = 4. The anionic partial structure consists of tetrahedral [B₄P₆O₂₄(OH)₂^8–] layers, which contain three‐ and nine‐membered rings. Co^II is octahedrally coordinated by oxygen and oxygen and H₂O ligands, respectively (coordination octahedra CoO₆ and CoO₄(H₂O)₂). Three adjacent coordination octahedra are condensed via common edges to form trimeric units (CoO₁₂(H₂O)₂). The oxidation state +2 of cobalt was confirmed by magnetic measurements. The octahedral trimers are quasi‐isolated. No long‐range magnetic ordering occurs down to 2 K. Rb⁺ is disordered over three crystallographically independent sites within channels of the structure running parallel [010]; the coordination sphere of Rb⁺ is formed by nine oxygen species of the tetrahedral layers, one OH group and one H₂O molecule.     

Ba2(Ni1−xLix)Ni2N2: Ein niedervalentes Nitridoniccolat mit gewellten Schichten [(NiN2/2)?(Ni1−xLix)?(NiN2/2)]

Ba₂(Ni_1?xLi_x)Ni₂N₂: A Low-Valency Nitridoniccolate with Puckered Layers [(NiN_2/2)? (Ni_1?xLi_x)? (NiN_2/2)] Ba₂(Ni_1?xLi_x)Ni₂N₂ is obtained by reaction of lithium-barium-melts (molar ratios Li : Ba between 1 : 1 and 3 : 1) with nitrogen (1 atm.) in nickel-crucibles within a period of 15 h. Single crystals with a dark-metallic lustre are formed by cooling the melt to room temperature with a rate of 10°C/h (orthorhombic, Cmca; a = 713.3(2)pm, b = 1027.4(7)pm, c = 752.2(4)pm; z = 4; D_xr = 5.50 g/cm³ with x = 0.43). The crystal structure contains nearly liner [NiN_2/2]-chains (N? Ni? N: 178.5(7)°, Ni? N? Ni 173.4(7)°; Ni? N: 178.6(1)pm), running parallel to the [100] direction, which are interconnected via (Ni_1?xLi_x)-sites (linear units (N? (Ni_1?xLi_x)? N); bond-lenths: 194.5(12)pm with x = 0.43) to form puckered layer [(Nin_2/2)? (Ni_1?xLi_x)? (NiN_2/2)]. Barium is in a distorted trigonal-planar coordination by nitrogen atoms (Ba? N: 281.1(11)pm ? 285.5(11)pm. The nitrogen-coordination corresponds to a distorted octahedron, NBa₃(Ni_1?xLi_x)Ni₂, with nickel in trans-position. The crystal structure of Ba₂(Ni_1?xLi_x)Ni₂N₂ is closely related to the Li₃N-type structure: Li₂[LiN] ? Ba{(Ni_1?xLi_x)_0.5 □ _0.5}[NiN]. Furthermore, this structure enlarges the scope of barium-nitrido-niccolates which up to now were found to contain merely [NiN_2/2]-chains(BaNiN: Planar zigzag-chains; Ba₈Ni₆N₇ helical zigzag-chains).