NaZr2N2SCl: Ein flußmittelstabilisiertes Derivat von Zirconium(IV)–Nitridsulfid (Zr2N2S)

NaZr₂N₂SCl: A Flux‐Stabilized Derivative of Zirconium(IV) Nitride Sulfide (Zr₂N₂S) The oxidation of zirconium metal with elemental sulfur and sodium azide (NaN₃) should give access to zirconium(IV) nitride sulfide, Zr₂N₂S, which could crystallize isotypically with the trigonal rare‐earth(III) oxide sulfides M₂O₂S (M = Y, La–Lu). Appropriate molar admixtures of these reactants together with NaCl added as flux were heated for seven days at 850 °C in torch‐sealed evacuated silica tubes. As main product, however, pale yellow platelets with the composition NaZr₂N₂SCl (trigonal, R 3 m; a = 363.56(3), c = 2951.2(4) pm; Z = 3) emerged as single crystals. This pseudo‐quaternary compound crystallizes isotypically with e. g. Li_xEr₂H_yCl₂ (x ≤ 1, y ≤ 2) in a (doubly) stuffed ZrBr‐type structure and contains at least structural domains of the hypothetical Ce₂O₂S‐analogous Zr₂N₂S. Zr⁴⁺ resides in monocapped trigonal anti‐prismatic sevenfold coordination of the anions (d(Zr–N) = 218 (3 ×) and 220 pm (1 ×), d(Zr–S/Cl) = 266 pm, 3 ×). Closest packed double‐layers of Zr⁴⁺ with all tetrahedral interstices occupied with N^3– are sandwiched by layers of isoelectronic S^2– and Cl^– anions. These anionic six‐layer slabs (S/Cl–Zr–N–N–Zr–S/Cl) pile up parallel (001) in a cubic closest packed fashion. Charge balance and structural consistence occurs between these layers by intercalation of Na⁺ within octahedral voids (d(Na–S/Cl) = 282 pm, 6 ×) of double‐layers of the indistinguishable heavy anions (S^2– and Cl^–).     

Two Hexagonal Series of Lanthanoid(III) Oxide Fluoride Selenides: M6O2F8Se3 (M = La – Nd) and M2OF2Se (M = Nd,Sm, Gd – Ho)

Two hexagonal series of lanthanoid(III) oxide fluoride selenides with similar structure types can be obtained by the reaction of the components MF₃, M₂O₃, M, and Se in sealed niobium tubes at 850 °C using CsI as fluxing agent. The compounds with the lighter and larger representatives (M = La – Nd) occur with the formula M₆O₂F₈Se₃, whereas with the heavier and smaller ones (M = Nd, Sm, Gd – Ho) their composition is M₂OF₂Se. For both systems single‐crystal determinations were used in all cases. The compounds crystallize in the hexagonal crystal system (space group: P6₃/m) with lattice parameters of a = 1394–1331 pm and c = 403–372 pm (Z = 2 for M₆O₂F₈Se₃ and Z = 6 for M₂OF₂Se). The (M1)³⁺ cations show different square antiprismatic coordination spheres with or without an extra capping fluoride anion. All (M2)³⁺ cations exhibit a ninefold coordination environment shaped as tricapped trigonal prism. In both structure types the Se^2– anions are sixfold coordinated as trigonal prisms of M³⁺ cations, being first condensed by edges to generate trimeric units and then via faces to form strands running along [001]. The light anions reside either in threefold triangular or in fourfold tetrahedral cationic coordination. For charge compensation, both structures have to contain a certain amount of oxide besides fluoride anions. Since F^– and O^2– can not be distinguished by X‐ray diffraction, bond‐valence calculations were used to address the problem of their adjunction to the available crystallographic sites.     

On the Anion Distribution in Zr7O8N4

The effect of anion distribution on the stability of β‐zirconium oxide nitride Zr₇O₈N₄ (trigonal, ; a = 953.80(2) pm, c = 884.98(3) pm, Z=3) has been investigated quantum‐chemically. In agreement with experimental results for the structurally related β′‐type zirconium oxide nitride (Zr₇O₁₁N₂) nitride anions occupy sites in the central polyhedron of a Bevan cluster (A₇X₁₂ unit) in the most stable configurations. Other relevant structural ordering parameters are minimization of N^3?···N^3? contacts and of the number of quasi‐linear N–Zr–N bonds. The calculated electronic structure of β‐Zr₇O₈N₄ is in qualitative agreement with experimental observations.     

About Lanthanoid Fluoride Selenide Oxoselenotantalates with the Composition Ln3F2Se2TaO4 (Ln = La – Nd)

After solid-state reactions of the light lanthanoid metals, their oxides and fluorides as well as selenium in sealed tantalum ampoules with sodium chloride as a fluxing agent at 850 °C for 8 days needle-shaped single crystals of Ln₃F₂Se₂TaO₄ (Ln = La – Nd) were obtained. They crystallize in the orthorhombic space group Pnma analogous to La₃F₂Se₂NbO₄ with a = 1133–1120 pm, b = 400–393 pm and c = 1812–1778 pm (Ln = La – Nd) for Z = 4 as the first known quinary lanthanoid(III) oxoselenotantalates(V) with fluoride and selenide anions. The three crystallographically different Ln³⁺ cations are all surrounded by nine anions (O^2–, F^– and Se^2–) each. Tantalum resides in an octahedral chalcogen coordination by forming trans-vertex oxygen-connected [TaO₅Se]^7– polyhedra, which build up chains ¹_∞{[TaO^V_2/2O^t_3/1Se^t_1/1]^5–} along [010]. The sites of the four crystallographically different oxygen atoms and the two distinct fluoride anions were established by bond-valence calculations. One fluorine and three oxygen atoms are surrounded tetrahedrally by cations, while another fluoride and oxide anion exhibit just triangular non-planar coordination spheres. The two independent Se^2– anions have five or six cationic neighbors.     

Zr7(Sb,Se)4 – eine polare Variante des Nb7P4-Strukturtyps

Zr₇(Sb,Se)₄ – a Polar Variant of the Nb₇P₄ Structure Type Single crystals of Zr₇Sb_1.6(1)Se_2,4 were obtained by arc-melting of compressed mixtures of Zr, ZrSb₂, and ZrSe₂, followed by annealing at 1300 °C in an induction furnace using traces of iodine to promote crystal growth. The crystal structure (a = 375.98(4), b = 1662.6(2), c = 1476.7(2) pm, V = 923.1(2) 10⁶ pm³, Cmc2₁, Z = 4) was determined by single crystal X-ray means. Zr₇Sb_1.6(1)Se_2.4 forms a unique polar structure composed of condensed tri-capped trigonal prismatic Zr₉ clusters, being stabilized by interstitial Sb/Se atoms. The remaining Sb and Se atoms reside in mono- and bi-capped trigonal prismatic Zr₇ and Zr₈ clusters, respectively, of the extended cluster network. Characteristic structural distinctions and relations between Zr₇(Sb,Se)₄ and congeneric Zr₇P₄ are highlighted.     

Na2ZrS3: Ein ternäres Sulfid des Zirconiums mit aufgefüllter AlCl3‐Struktur

Na₂ZrS₃: A Ternary Zirconium Sulfide with Stuffed AlCl₃‐type Structure Dark green, plate‐like single crystals of Na₂ZrS₃ (monoclinic, C2/m; a = 664.69(6), b = 1152.5(1), c = 695.48(7) pm, β = 108.78(1)°; Z = 4) are obtained along with pale yellow platelets of NaZr₂N₂SCl (trigonal, R3m; a = 363.56(3), c = 2951.2(4) pm; Z = 3) upon oxidation of zirconium metal with sulfur and sodium azide (NaN₃) in the presence of fluxing NaCl (molar ratio 7:6:2:3) in evacuated silica tubes at 850°C within three weeks. The crystal structure is best described as stuffed AlCl₃ type with all cations (Na⁺ and Zr⁴⁺) in octahedral coordination of the S^2– anions, which build up a cubic closest packed host lattice. The internuclear metal sulfur distances range from 276 to 296 pm for all three crystallographically different Na⁺ cations, and from 258 to 260 pm for Zr⁴⁺.     

Rb6LiPr11Cl16[SeO3]12: Ein chloridisch derivatisiertes Rubidium‐Lithium‐Praseodym(III)‐Oxoselenat(IV)

Rb₆LiPr₁₁Cl₁₆[SeO₃]₁₂: A Chloride‐Derivatized Rubidium Lithium Praseodymium(III) Oxoselenate(IV) Transparent green square platelets with often truncated edges and corners of Rb₆LiPr₁₁Cl₁₆[SeO₃]₁₂ were obtained by the reaction of elemental praseodymium, praseodymium(III,IV) oxide and selenium dioxide with an eutectic LiCl–RbCl flux at 500 °C in evacuated silica ampoules. A single crystal of the moisture and air insensitive compound was characterized by X‐ray diffraction single‐crystal structure analysis. Rb₆LiPr₁₁Cl₁₆[SeO₃]₁₂ crystallizes tetragonally in the space group I4/mcm (no. 140; a = 1590.58(6) pm, c = 2478.97(9) pm, c/a = 1.559; Z = 4). The crystal structure is characterized by two types of layers parallel to the (001) plane following the sequence 121′2′1. Cl^? anions form cubes around the Rb⁺ cations (Rb1 and Rb2; CN = 8; d(Rb⁺?Cl^?) = 331 – 366 pm) within the first layer. One quarter of the possible places for Rb⁺ cations within this CsCl‐type kind of arrangement is not occupied, however the Cl^? anions of these vacancies are connected to Pr³⁺ cations (Pr4) above and below instead, forming square antiprisms of [(Pr4)O₄Cl₄]^9? units (d(Pr4?O) = 247–249 pm; d(Pr4?Cl) = 284–297 pm) that work as links between layer 1 and 2. Central cations of the second layer consist of Li⁺ and Pr³⁺. While the Li⁺ cations are surrounded by eight O^2? anions (d(Li?O5) = 251 pm) in the shape of cubes again, the Pr³⁺ cations are likewisely coordinated by eight O^2? anions as square antiprisms (for Pr1, d(Pr1?O2) = 242 pm) and by ten O^2? anions (for Pr2 and Pr3), respectively. The latter form tetracapped trigonal antiprisms (Pr2, d(Pr2?O) = 251–253 pm and 4 × 262 pm) or bicapped distorted cubes (Pr3, d(Pr3?O) = 245–259 pm and 2 × 279 pm). The non‐binding electron pairs (“lone pairs”) at the two crystallographically different Ψ¹‐tetrahedral [SeO₃]^2? anions (d(Se⁴⁺?O^2?) = 169–173 pm) are directing towards the empty cavities between the layer‐connecting [(Pr4)O₄Cl₄]^9? units.     

Quaternäre Caesium‐Kupfer(I)‐Lanthanoid(III)‐Selenide vom Typ CsCu3M2Se5 (M = Sm,Gd — Lu)

Quaternary Cesium Copper(I) Lanthanoid(III) Selenides of the Type CsCu₃M₂Se₅ (M = Sm, Gd — Lu) By oxidation of mixtures of copper and lanthanoid metal with elemental selenium in molar ratios of 1 : 1 : 2 and in addition of CsCl quaternary cesium copper(I) lanthanoid(III) selenides with the formula CsCu₃M₂Se₅ (M = Sm, Gd — Lu) were obtained at 750 °C within a week from torch‐sealed evacuated silica tubes. An excess of CsCl as flux helps to crystallize golden yellow or red, needle‐shaped, water‐resistant single crystals. The crystal structure of CsCu₃M₂Se₅ (M = Sm, Gd — Lu) (orthorhombic, Cmcm, Z = 4; e. g. CsCu₃Sm₂Se₅: a = 417.84(3), b = 1470.91(8), c = 1764.78(9) pm and CsCu₃Lu₂Se₅: a = 407.63(3), b = 1464.86(8), c = 1707.21(9) pm, respectively) contains [MSe₆]^9— octahedra which share edges to form double chains running along [100]. Those are further connected by vertices to generate a two‐dimensional layer parallel to (010). By edge‐ and vertex‐linking of [CuSe₄]^7— tetrahedra two crystallographically different Cu⁺ cations build up two‐dimensional puckered layers parallel to (010) as well. These sheet‐like structure interconnects the equation/tex2gif-stack-3.gif{[M₂Se₅]^4—} layers to create a three‐dimensional network according to equation/tex2gif-stack-4.gif{[Cu₃M₂Se₅]^—}. Thus empty channels along [100] form, apt to take up the Cs⁺ cations. These are surrounded by eight plus one Se^2— anions in the shape of (2+1)‐fold capped trigonal prisms with Cs—Se distances between 348 and 368 pm (8×) and 437 (for M = Sm) or 440 pm (for M = Lu), respectively, for the ninth ligand.     

Copper(I) d10···d10 Interactions and Diselenide(1–) Radical Anions in Mixed Valent Selenides Cu4–δBiSe4I

Melting reactions of copper, CuI, selenium, and Bi₂Se₃ yielded black, shiny needles of Cu₄BiSe₄I = Cu₄BiSe₂(Se₂)I. The compound decomposes peritectically above 635(5) K and crystallizes in the orthorhombic space group Pnma with a = 960.1(1) pm, b = 413.16(3) pm, and c = 2274.7(2) pm (T = 293(2) K). In the crystal structure, strands ${1}\atop{{\infty}}$ [BiSeSe_2/2(Se₂)_2/2]^3– run along [010]. Therein, the bismuth(III) cation is coordinated by five selenium atoms, which form a square pyramid. The copper(I) cations are coordinated tetrahedrally by selenide, diselenide and iodide ions. Edge‐sharing of these tetrahedra results in zigzag chains of copper cations with short distances of 262.7(4) pm. Enhanced dispersion of the 3d bands, the Crystal Orbital Hamilton Populations (COHP), and disynaptic ELI‐D basins indicate weakly attractive d¹⁰···d¹⁰ interactions between the copper cations. The semiconducting properties and the calculated electronic band structure suggest an electron‐precise compound. In copper‐deficient Cu_3.824(8)BiSe₄I, the Cu···Cu distances are 5 pm shorter, and Raman spectroscopy indicates the presence of diselenide(1–) radical anions besides the diselenide(2–) groups. As a result, in Cu_3.824(8)BiSe₄I, selenium coexists in the oxidations states –II, –I, and –0.5.     

Temperature Influence on the Formation of Selenidoantimonates: Solvothermal Syntheses,Crystal Structures and Thermal Properties of [Ni(dien)2]2Sb2Se6, [Mn(dien)2]2(SbSe4)(Cl), [Co(dien)2]2(SbSe4)(Br), and [Co(dien)2]3(SbSe4)2

New selenidoantimonats [Ni(dien)₂]₂Sb₂Se₆ ( 1 ), [Mn(dien)₂]₂(SbSe₄)(Cl) ( 2 ), [Co(dien)₂]₂(SbSe₄)(Br) ( 3 ), and [Co(dien)₂]₃(SbSe₄)₂ ( 4 ) (dien = diethylenetriamine) were solvothermally synthesized in dien solvent at 180 °C. The crystal structure of 1 consists of two octahedral [Ni(dien)₂]²⁺ cations and a mixed‐valent [Sb₂Se₆]^4? anion. The isolated [Sb₂Se₆]^4? anion is formed by a Sb^IIISe₃ trigonal pyramid and a Sb^VSe₄ tetrahedron sharing a common corner. 2 and 3 are composed of octahedral [M(dien)₂]²⁺ cations, tetrahedral [SbSe₄]^3? anions and halide ions forming an extended network through hydrogen‐bonding interactions. In 4 the [Co(1)(dien)₂]²⁺, [Co(2)(dien)₂]²⁺ and [SbSe₄]^3? ions form layered structures via N–H···Se hydrogen bonds. The [Co(3)(dien)₂]²⁺ ion is located between the layers, and interacts with the layers by N–H···Se bonds. The synthesis and solid state structural studies on the title compounds show that the higher reaction temperature is helpful for the formation of selenidoantimonate(V) compounds in the synthesis of selenidoantimonate from the M²⁺/Sb/Se/dien system. 1 – 4 start to decompose at temperature about 210 °C in N₂ atmosphere. They lose dien ligands at a wide temperature range of 210–450 °C with multisteps for 1 – 3 and a single step for 4 .     

Copper Bismuth Chalcogenide Halogenides with Extensively Disordered and Mobile Copper(I) Cations

A new family of quaternary phases with the general sum formula Cu_3+δBi_5–δSe_8–2δX_2+2δ (X = Cl, Br) was discovered by slow cooling of high temperature melts. Cu_3.58(1)Bi_4.42(1)Se_6.84(2)Cl_3.16(2) (δ = 0.58) and Cu_4.52(1)Bi_3.48(1)Se_4.96(2)Br_5.04(2) (δ = 1.52) crystallize isostructural in the orthorhombic space group type Pnnm with a = 1332.3(1)/1340.2(3) pm, b = 1683.7(2)/1717.2(1) pm, and c = 406.2(1)/407.1(2) pm. The new structure type resembles in some aspects the hollandite as well as the pavonite type. A framework of face‐ and edge‐sharing anion polyhedra around Bi³⁺ cations hosts Cu⁺ cations. The characteristic motif is an infinite band of polyhedra that has the width of five polyhedra, with three octahedra being enclosed by capped trigonal prisms. The octahedrally coordinated Bi³⁺ cations are partially substituted by Cu⁺ (in octahedra faces), while Se^2– anions are replaced by X^–. The sulfide iodide Cu_3.33(2)Bi₂S_3.33(2)I_2.67(2) crystallizes in the monoclinic space group C2/m with a = 2803.6(9) pm, b = 409.9(1) pm, c = 1058.0(3) pm, and β = 110.68(2)°. Double strands of face‐sharing [BiS_1/1S_2/2I_4/4] as well as [BiS_3/3I_2/2(S_0.33/I_0.67)_2/2] polyhedra run along [010]. In between them, the Cu⁺ cations are spread over numerous closely spaced sites. They define a ladder‐shaped continuous path for ion conduction along [010].     

Li2Eu3Br2[BO3]2: A New Europium(II) Halide Oxoborate with Yellow Luminescence

The europium(II) oxoborate Li₂Eu₃Br₂[BO₃]₂ featuring lithium and bromide ions was synthesized by the reaction of Eu₂O₃ with Li[BH₄] as lithium- and boron- as well as EuBr₃ as bromide-source at 750 °C for 24 h in silica-jacketed sealed niobium capsules. The yellow, air-stable and yellow fluorescent compound crystallizes in the trigonal space group R3 m (a = 1049.06(7) pm, c = 2993.1(3) pm, c/a = 2.853, Z = 12). The two crystallographically distinguishable Eu²⁺ cations show either an eightfold coordination as bicapped trigonal prism ([EuO₆Br₂]^12–) or a ninefold coordination as monocapped square antiprism ([EuO₅Br₄]^12–). All oxygen atoms stem from isolated triangular [BO₃]^3– anions and the Li⁺ cations reside in octahedral voids provided by both oxygen atoms and Br^– anions.     

La3OCl[AsO3]2: Ein Lanthan‐Oxidchlorid‐Oxoarsenat(III) mit “lone‐pair”‐Kanalstruktur

La₃OCl[AsO₃]₂: A Lanthanum Oxide Chloride Oxoarsenate(III) with a “Lone‐Pair” Channel Structure La₃OCl[AsO₃]₂ was prepared by the solid‐state reaction between La₂O₃ and As₂O₃ using LaCl₃ and CsCl as fluxing agents in evacuated silica ampoules at 850 °C. The colourless crystals with pillar‐shaped habit crystallize tetragonally (a = 1299.96(9), c = 558.37(5) pm, c/a = 0.430) in the space group P4₂/mnm (no. 136) with four formula units per unit cell. The crystal structure contains two crystallographically different La³⁺ cations. (La1)³⁺ is coordinated by six oxygen atoms and two chloride anions in the shape of a bicapped trigonal prism (CN = 8), whereas (La2)³⁺ carries eight oxygen atoms and one Cl^? anion arranged in the shape of tricapped trigonal prism (CN = 9). The isolated pyramidal [AsO₃]^3? anions (d(As–O) = 175–179 pm) consist of three oxygen atoms (O2 and two O3), which surround the As³⁺ cations together with the free, non‐binding electron pair (lone pair) Ψ¹‐tetrahedrally (?(O–As–O) = 95°, 3×). One of the three crystallographically independent oxygen atoms (O1), however, is exclusively coordinated by four (La2)³⁺ cations in the shape of a real tetrahedron (d(O–La) = 236 pm, 4×). These [(O1)(La2)₄]¹⁰⁺ tetrahedra form endless chains in the direction of the c axis through trans‐edge condensation. Empty channels, constituted by the lone‐pair electrons of the Cl^? anions and the As³⁺ cations in the Ψ¹‐tetrahedral oxoarsenate(III) anions [AsO₃]^3?, run parallel to [001] as well.     

The First Examples of Selenidogermanate Salts with Lanthanide Complex Counter Cations: Solvothermal Syntheses and Characterizations of [{Ln(en)3}2(μ‐OH)2]Ge2Se6 (Ln = Eu,Ho) and [{Ho(dien)2}2(μ‐OH)2]Ge2Se6

The lanthanide selenidogermanates [{Eu(en)₃}₂(μ‐OH)₂]Ge₂Se₆ ( 1 ), [{Ho(en)₃}₂(μ‐OH)₂]Ge₂Se₆ ( 2 ), and [{Ho(dien)₂}₂(μ‐OH)₂]Ge₂Se₆ ( 3 ) (en = ethylenediamine, dien = diethylenetriamine) were solvothermally prepared by the reactions of Eu₂O₃ (or Ho₂O₃), germanium, and selenium in en and dien solvents respectively. Compounds 1 – 3 are composed of selenidogermanate [Ge₂Se₆]^4– anion and dinuclear lanthanide complex cation [{Ln(en)₃}₂(μ‐OH)₂]⁴⁺ (Ln = Eu, Ho) or [{Ho(dien)₂}₂(μ‐OH)₂]⁴⁺. The [Ge₂Se₆]^4– anion is composed of two GeSe₄ tetrahedra sharing a common edge. The dinuclear lanthanide complex cations are built up from two [Ln(en)₃]³⁺ or [Ho(dien)₂]³⁺ ions joined by two μ‐OH bridges. All lanthanide(III) ions are in eight‐coordinate environments forming distorted bicapped trigonal prisms. In 1 – 3 , three‐dimensional supramolecular networks of the anions and cations are formed by N–H ··· Se and N–H ··· O hydrogen bonds. To the best of our knowledge, 1 – 3 are the first examples of selenidogermanate salts with lanthanide complex counter cations.     

Vier Oxidselenide des Praseodyms: Pr10OSe14, Pr2OSe2, Pr2O2Se und Pr4O4Se3

Four Oxyselenides of Praseodymium: Pr₁₀OSe₁₄, Pr₂OSe₂, Pr₂O₂Se, and Pr₄O₄Se₃ By reacting elemental praseodymium with selenium and selenium dioxide (SeO₂) as oxygen source in suitable stoichiometric ratios, it is possible to prepare the single‐phase praseodymium(III) oxyselenides Pr₁₀OSe₁₄, Pr₂OSe₂, Pr₂O₂Se, and Pr₄O₄Se₃ each within seven days at 750 °C in torch‐sealed evacuated silica tubes. The addition of equimolar amounts of CsCl as flux guarantees quick and complete reactions to single‐crystalline, water‐ and air‐resistant products. Pr₁₀OSe₁₄ (tetragonal, I4₁/acd; a = 1568.74(8), c = 2073.4(1) pm; Z = 8) crystallizes as dark‐red polyhedra. Pr₂OSe₂ (monoclinic, P2₁/c; a = 882.05(6), b = 732.89(5), c = 732.94(5) pm, β = 100.288(7)°; Z = 4) and Pr₂O₂Se (trigonal, P3m1; a = 401.12(3), c = 705.51(5) pm; Z = 1) accumulate as yellowish green platelets with rectangular and hexagonal cross‐sections, respectively. Pr₄O₄Se₃ (orthorhombic, Amm2; a = 849.92(6), b = 402.78(3), c = 1292.57(9) pm; Z = 2) forms lath‐shaped, pleochroitic crystals with a strong tendency for twinning, which appear green along [001], but red along [100] and [010]. All the crystal structures of these oxyselenides are dominated by [OPr₄] tetrahedra, whose condensation rate strongly increases with growing oxygen content. Se^2– anions, in the case of Pr₄O₄Se₃ (≡ {(Pr³⁺)₄(O^2–)₄(Se^2–)[Se₂]^2–}) as well as [Se₂]^2– dumb‐bells, take care of charge balance and threedimensional cross‐linkage. In the oxygen‐poor Pr₁₀OSe₁₄ the [OPr₄]¹⁰⁺ tetrahedra occur isolated and are embedded in the complex anionic matrix framework {(Pr₆Se₁₄)^10–}. The oxygen‐rich links in this row show according to {[OPr_3/3Pr_1/1]}Se₂ (≡ Pr₂OSe₂), {([OPr_4/4]₂)}Se (≡ Pr₂O₂Se), and {([OPr_4/4]₄)}[Se₂]Se (≡ Pr₄O₄Se₃) [OPr₄] tetrahedra which are connected to more or less dense layers via corners and respectively one, three and four common edges.     

Das Lanthan‐Dodekahydro‐closo‐Dodekaborat‐Hydrat [La(H2O)9]2[B12H12]3·15 H2O und sein Oxonium‐Chlorid‐Derivat [La(H2O)9](H3O)Cl2[B12H12]·H2O

The Lanthanum Dodecahydro‐closo‐Dodecaborate Hydrate [La(H₂O)₉]₂[B₁₂H₁₂]₃·15 H₂O and its Oxonium‐Chloride Derivative [La(H₂O)₉](H₃O)Cl₂[B₁₂H₁₂]·H₂O By neutralization of an aqueous solution of the free acid (H₃O)₂[B₁₂H₁₂] with basic La₂O₃ and after isothermic evaporation colourless, face‐rich single crystals of a water‐rich lanthanum(III) dodecahydro‐closo‐dodecaborate hydrate [La(H₂O)₉]₂[B₁₂H₁₂]₃·15 H₂O are isolated. The compound crystallizes in the trigonal system with the centrosymmetric space group (a = 1189.95(2), c = 7313.27(9) pm, c/a = 6.146; Z = 6; measuring temperature: 100 K). The crystal structure of [La(H₂O)₉]₂[B₁₂H₁₂]₃·15 H₂O can be characterized by two of each other independent, one into another posed motives of lattice components. The [B₁₂H₁₂]²⁻ anions (d(B–B) = 177–179 pm; d(B–H) = 105–116 pm) are arranged according to the samarium structure, while the La³⁺ cations are arranged according to the copper structure. The lanthanum cations are coordinated in first sphere by nine oxygen atoms from water molecules in form of a threecapped trigonal prism (d(La–O) = 251–262 pm). A coordinative influence of the [B₁₂H₁₂]²⁻ anions on La³⁺ has not been determined. Since “zeolitic” water of hydratation is also present, obviously the classical H–O^δ–···^+δH–O‐hydrogen bonds play a significant role in the stabilization of the crystal structure. During the conversion of an aqueous solution of (H₃O)₂[B₁₂H₁₂] with lanthanum trichloride an anion‐mixed salt with the composition [La(H₂O)₉](H₃O)Cl₂[B₁₂H₁₂]·H₂O is obtained. The compound crystallizes in the hexagonal system with the non‐centrosymmetric space group (a = 808.84(3), c = 2064.51(8) pm, c/a = 2.552; Z = 2; measuring temperature: 293 K). The crystal structure can be characterized as a layer‐like structure, in which [B₁₂H₁₂]²⁻ anions and H₃O⁺ cations alternate with layers of [La(H₂O)₉]³⁺ cations (d(La–O) = 252–260 pm) and Cl⁻ anions along [001]. The [B₁₂H₁₂]²⁻ (d(B–B) = 176–179 pm; d(B–H) = 104–113 pm) and Cl⁻ anions exhibit no coordinative influence on La³⁺. Hydrogen bonds are formed between the H₃O⁺ cations and [B₁₂H₁₂]²⁻ anions, also between the water molecules of [La(H₂O)₉]³⁺ and Cl⁻ anions, which contribute to the stabilization of the crystal structure.     

Nd4N2Se3 und Tb4N2Se3: Zwei nicht‐isotype Lanthanoid(III)‐Nitridselenide

Nd₄N₂Se₃ and Tb₄N₂Se₃: Two non‐isotypical Lanthanide(III) Nitride Selenides The non‐isotypical nitride selenides M₄N₂Se₃ of neodymium (Nd₄N₂Se₃) and terbium (Tb₄N₂Se₃) are formed by the reaction of the respective rare‐earth metal with sodium azide (NaN₃), selenium and the corresponding rare‐earth tribromide (MBr₃) at 900 °C in evacuated silica ampoules after seven days. Each of them crystallizes monoclinically in the space group C2/c with Z = 4 for Nd₄N₂Se₃ (a = 1300.47(4), b = 1009.90(3), c = 643.33(2) pm, β = 90.039(2)°) and in the space group C2/m with Z = 2 for Tb₄N₂Se₃ (a = 1333.56(5), b = 394.30(2), c = 1034.37(4) pm, β = 130.377(2)°), respectively. The crystal structures differ fundamentally in the linkage of the structure dominating N^3‐ centred (M³⁺)₄ tetrahedra. In Nd₄N₂Se₃, the [NNd₄] units are edge‐linked to bitetrahedra which are cross‐connected to [N(Nd1)(Nd2)]³⁺ layers via their remaining four corners, whereas the [NTb₄] tetrahedra in Tb₄N₂Se₃ share cis‐oriented edges to form strands [N(Tb1)(Tb2)]³⁺. Both structures contain two crystallographically different M³⁺ cations, that show coordination numbers of six and seven (Nd₄N₂Se₃) or twice six (Tb₄N₂Se₃), respectively, relative to the anions (N^3‐ und Se^2‐). Each of the two independent kinds of Se^2‐ anions provide the three‐dimensional linkage as well as the charge balance. The particular axial ratio a/c and the monoclinic reflex angle offer two choices for fixing the unit cell of Tb₄N₂Se₃.     

Homoleptic Octahedral Methylamine Complexes of Manganese(II): Solvothermal Syntheses and Crystal Structures of [Mn(NH2CH3)6]Cl2 and the Pentaselenide [Mn(NH2CH3)6]Se5

[Mn(NH₂CH₃)₆]Cl₂ ( 1 ) and [Mn(NH₂CH₃)₆]Se₅ ( 2 ) were prepared by solvothermal reactions in liquid methylamine from MnCl₂ at 150 °C for 1 and from a mixture of MnCl₂, Rb₂Se and selenium at 120 °C for 2 . Both 1 and 2 were obtained in high yields as colorless and dark‐red crystals and represent the first homoleptic methylamine complexes with coordination number six. Compound 1 crystallizes rhombohedral (R$\bar{3}$ , Z = 3) and is built of only slightly distorted octahedral [Mn(NH₂CH₃)₆]²⁺ cations and Cl^– anions. Compound 2 crystallizes orthorhombic (Pnna, Z = 4) and is built of octahedral [Mn(NH₂CH₃)₆]²⁺ cations showing a strong angular distortion and of Se₅^2– anions in the form of chains in transoid conformation. DFT calculations reveal an almost undistorted ground state structure for [Mn(NH₂CH₃)₆]²⁺ with N–Mn–N angular distortions of 1° from orthogonality, close to the structure found for the complex in 1 . The calculated energy necessary for a distortion as found in the structure of 2 is rather low and amounts to 26 kJmol^–1 which is in the range typical for hydrogen bonds. The N–Mn–N angular distortions of the complex cation in 2 , observed in the range of 10°, is caused by cation‐anion interactions in the crystal structure by N–H ···· Se hydrogen bonds.     

[Ga(en)3][Ga3Se7(en)] · H2O: Ein Galliumchalkogenid mit Ketten aus [Ga3Se6Se2/2(en)]3–-Bicyclen

[Ga(en)₃][Ga₃Se₇(en)] · H₂O: A Gallium Chalcogenide with Chains of [Ga₃Se₆Se_2/2(en)]^3– Bicycles The new selenidogallate [Ga(en)₃][Ga₃Se₇(en)] · H₂O ( I ) was produced from a ethylendiamine suspension of Ga and Se at 130 °C. I crystallizes in the orthorhombic space group Pna2₁ with unit constants a = 1347.9(3) pm, b = 961.6(1) pm, c = 1967.6(4) pm and Z = 4. The crystal structure contains an anion so far not observed in gallium chalcogenides. It is built from [Ga₃Se₆Se_2/2(en)]^3– bicycles of three Ga^IIIL₄ tetrahedra (L = en, Se) connected via selenium corners to linear chains. The cations, Ga^III ions coordinated by three ethylendiamine in a distorted octahedral geometry are positioned in the holes of the hexagonal rod packing of these chains.