La4N2S3: Ein neues Nitridsulfid des Lanthans mit beispielloser Kristallstruktur

La₄N₂S₃: A New Nitride Sulfide of Lanthanum with Unprecedented Crystal Structure The oxidation of lanthanum powder with sulfur and cesium azide (CsN₃) in the presence of lanthanum tribromide (LaBr₃) yields lanthanum nitride sulfide with the composition La₄N₂S₃ when appropriate molar ratios of the reactants are used. Additional cesium bromide (CsBr) as a flux secures fast reactions (7 d) at 900 °C in evacuated silica tubes as well as the formation of almost black single crystals. The orthorhombic crystal structure (Pnnm, Z = 2) was determined from single crystal X‐ray diffraction data (a = 641.98(4), b = 1581.42(9), c = 409.87(3) pm). Two crystallographically different La³⁺ cations are present, La1 resides in sixfold coordination of two N^3? and four S^2? anions forming a trigonal prism and La2 is coordinated by two N^3? and five S^2? in the shape of a monocapped trigonal prism. However, the main feature of the crystal structure comprises N^3?‐centred (La³⁺)₄ tetrahedra which arrange as pairs [N₂La₆]¹²⁺ of edge‐shared [NLa₄]⁹⁺ units and which are further connected via four vertices to form double chains . They get bundled along [001] like a hexagonal rod packing and are held together by two crystallographically different S^2? anions. Further motifs for the connectivity of [NM₄]⁹⁺ tetrahedra in crystal structures of nitride chalcogenides and halides of the rare‐earth elements (M = Sc, Y, La; Ce – Lu) with ratios of N : M = 1 : 2 are presented and discussed for comparison.     

Die colorimetrische Mikrobestimmung des Bors mit Chromotrop 2 B

Ohne Zusammenfassung Martin, G., und M. Maës: Bull. Soc. Chim. biol. 34, 1177 (1952)     

Ein neues Cobaltat mit Inselstruktur: Li6[CoO4]

A New Cobaltate with Isolated Anion Structure: Li₆[CoO₄] For the first time transparent, blue single crystals of Li₆[CoO₄] have been prepared (Li₂O/Na₂O/?CoO”? (Li:Na:Co = 1.3:1.3:1), Co-tube, 580°C, 22 d). Corresponding to Li₆□CoO; it is an ordered variant of the Li₂O-type of structure: P4₂/nmc; a = 653.6(1) pm, c = 465.4(1) pm; Z = 2; d_x = 2.75 g cm^?3, d_pyk = 2.71 g cm^?3 (4-circle-diffractometer-data (PW 1100), AgKα; 230 from 936 I₀(hkl); R = 9.58%, R_W = 5.25%). Parameters see text. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed. The magnetic properties are measured in the temperature range of 14–297 K.     

Ein neues Verfahren der volumetrischen Bestimmung des Ammoniak- und Harnstoffstickstoffs mit der Hypobromitmethode

Ohne Zusammenfassung     

Ein neues Oxotantalat mit bronzeähnlicher Kristallstruktur: Ba4CoTa10O30

Solide state reactions lead to the hitherto unknown compound Ba₄CoTa₁₀O₃₀. X-ray single crystal work (space group C _2v ¹⁴ -Amm2,a=3.905,b=10.203 andc=14.954 Å) shows, that the octahedron network of Ba₄CoTa₁₀O₃₀ is conform to the Na₂Nb₁₂O₃₀ F₂-Type. On the other hand the occupation of the tunnels is related to the bronze-structure. The different structure types are discussed.

     

Eine β-Tonerde mit Cu2+ in tetraedrischer Koordination: (Ba,Sr)CuAl10O17

A β-Alumina Containing Tetrahedric Coordinated Cu²⁺: (Ba, Sr)CuAl₁₀O₁₇ (Ba, Sr)CuAl₁₀O₁₇ single crystals can be obtained by reaction of BaCuO₂ and SrCuO₂ with Al₂O₃ in oxygen atmosphere ar 1400°C. It crystallizes with hexagonal symmetry, space group D–P6₃/mmc, a = 5.604; c = 22.678 Å; Z = 2. X-ray single crystal investigation led to the β-Alumina-type. Cu²⁺- and Al³⁺-ions occupy tetrahedra positions within the AlO₆-octahedra blocks.     

NaPr9S2[SiO4]6: Ein Sulfidsilicat des Praseodyms mit Bromapatitstruktur

NaPr₉S₂[SiO₄]₆: A Sulfide Silicate of Praseodymium with the Structure of Bromapatite NaPr₉S₂[SiO₄]₆ is obtained as pale green single crystals of hexagonal columnar shape from reactions of Pr, Pr₆O₁₁, S, SiO₂ and NaCl (850°C, 7 d) in fused evacuated silica tubes. The crystal structure (hexagonal, P6₃/m, Z = 1, a = 981.05(4), c = 689.68(2) pm) corresponds with a modified bromapatite structure where orthosilicate ([SiO₄]^4?) and sulfide (S^2?) anions provide coordination numbers of eight and nine to the two crystallographically different cations. These occupy the positions 4 f (Na⁺ together with Pr³⁺ in a molar ratio of 1:3) and 6h (Pr³⁺ only) to realize an average Ca₅Br[PO₄]₃-type structure.     

Ein neues Oxocadmat mit Tetraeder-Blöcken: Cs14Cd9O16

A New Oxocadmate with Blocks of Tetrahedrons: Cs₁₄Cd₉O₁₆ We prepared hitherto unknown Cs₁₄Cd₉O₁₆ in the form of pale yellow single crystals (a = 2087.2; b = 674.4; c = 2583.8 pm; β = 94.55°; Z = 4; space group: C2/c). The crystal structure was solved by four-circle-diffractometer data [Philips PW 1100, MoKα, R = 9.9%, R_w = 8.8% for 2774 of 3581 I_o(hkl)]. The dominant features of the structure are infinite chains [Cd₉O₁₆] with [2 × 3]-blocks of tetrahedrons. Effective Coordination Numbers, ECoN, and the Madelung Part of Lattice Energy, MAPLE, are calculated and discussed.     

Er2S[SiO4]: Ein Erbiumsulfid‐ortho‐Oxosilicat mit ungewöhnlicher Sulfidionen‐Koordination

During the reaction of cadmium sulfide with erbium and sulfur in evacuated silica ampoules pink lath‐shaped crystals of Er₂S[SiO₄] occur as by‐product which were characterized by X‐ray single crystal structure analysis. The title compound crystallizes orthorhombically in the space group Cmce (a = 1070.02(8), b = 1235.48(9), c = 683.64(6) pm) with eight formula units per unit cell. Besides isolated ortho‐oxosilicate units [SiO₄]^4?, the crystal structure contains two crystallographically independent Er³⁺ cations which are both eightfold coordinated by six oxygen and two sulfur atoms. The sulfide anions are surrounded by four erbium cations each in the shape of very distorted tetrahedra. These excentric [SEr₄]¹⁰⁺ tetrahedra build up layers according to by vertex‐ and edge‐connection. They are piled parallel to (010) and separated by the isolated ortho‐oxosilicate tetrahedra.     

Ein neues Samariumnitridsulfid: Sm4N2S3

A New Samarium Nitride Sulfide: Sm₄N₂S₃ The oxidation of samarium with sulfur in the presence of SmCl₃ and NaN₃ as nitrogen source (molar ratio: 12:9:4:2, evacuated silica vessel, some NaCl as flux, 850°C, 7 d) yields Sm₄N₂S₃ as lath-shaped, dark red single crystals. The by-products (NaCl and NaSm₂Cl₆) are rinsed with water from the crude product. The crystal structure of Sm₄N₂S₃ (monoclinic, C2/m (no. 12), Z = 2, a = 1 318.04(12), b = 391.57(2), c = 1 031.76(9) pm, β = 130.874(6)°, R = 0.036, R_w = 0.031) contains two crystallographically different Sm³⁺, both in sixfold coordination of the anions. Besides distorted octahedra [(Sm1)N₃S₃] and [(Sm2)NS₅], tetrahedra [(N^3?)(Sm)] connected via two cis-oriented edges to form chains [N(Sm1)_3/3(Sm2)_1/1]³⁺ build up the Mayn structural feature. These are arranged in the fashion of a closest packing of rods and held together by two crystallographically different S^2? anions which take care for charge neutrality and three-dimensional interconnection.     

Ag2Pb8O7Cl4, Ein neues Blei(II)-oxidhalogenid mit Silber

Ag₂Pb₈O₇Cl₄, a New Member of Lead(II) Oxyhalides with Silver Ag₂Pb₈O₇Cl₄ is one among other products of the thermal decomposition of AgPb₄O₄Cl. Ag₂Pb₈O₇Cl₄ can be prepared directly by heating the binary components within a temperature range from 590°C to 620°C. The crystal structure was solved by single crystal X-ray methods. The compound crystallizes monoclinic with a = 12.411(4) Å, b = 17.99(3) Å, c = 14.785(4) Å, β = 147.01(2)°, Z = 4 with the space group P2₁/c. Ag₂Pb₈O₇Cl₄ shows remarkable structural features, e.g. silver tetrahedrally surrounded by chlorine.     

Ein neues Kupfercobaltboratoxid mit isolierten B2O5-Baugruppen: Cu2Co(B2O5)O

On a New Copper Cobalt Borate Oxide with Isolated B₂O₅ Units: Cu₂Co(B₂O₅)O Single crystals of a new compound with the empirical formula Cu₂CoB₂O₆ were obtained by using a B₂O₃ flux technique. X-ray single crystal technique led to a new structure type. Cu₂CoB₂O₆ crystallizes monoclinic, space group C-P2₁/c (No. 14); a = 3.2250(6); b = 14.847(1); c = 9.1171(6) Å; β = 93.67°; Z = 4. All metal sites are octahedrally coordinated and form a two dimensional framework consisting of edge sharing octahedra ribbons. In addition one observes isolated B₂O₅-units and oxygen which is not coordinated to boron. The far relation to the crystal structure of the mineral Warwickite is illustrated.     

Ein neues metastabiles Oxometallat mit Tunnelstruktur: Ba2SrLu22O36

A New Metastable Oxocompound with Tunnel Structure: Ba₂SrLu₂₂O₃₆ High temperature reactions yield single crystals of a new metastable compound: Ba₂SrLu₂₂O₃₆ (hexagonal symmetry, space group C–P6₃/m, a = 17.60(6), c = 3.33(4) Å, Z = 1). X-ray results led to an octahedra framework with two types of tunnels. A comparative discussion of the tunnel occupation is given.     

Ein neues Oxoiridat(V): KLi6[IrO6]

A New Oxoiridate(V): KLi₆[IrO₆] Hitherto unknown Kli₆[IrO₆] has been prepared by completely pulverized mixtures of K₄[IrO₄] and Li₂O (closed silver cylinder, 30 d, 750°C). The deep dark red single crystals are trigonal-rhombohedral, space group R3 m, a = 819.61(8) pm, c = 709.96(11) pm, Z = 3. It is a “stuffed” variant of the α-Li₆[UO₆]-type; four-circle diffractometer data (PW 1100), R = 1.44% and R_w = 1.41% for 220 I₀(h kl), MoKα. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, the latter derived from mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Cp*Me5P6C5: Ein neues Carbaphosphan mit einem Strukturelement aus dem Hittorfschen Phosphor

Cp*Me₅P₆C₅: A New Carbaphosphane with a Structure Unit of Hittorf-Phosphorus The thermolysis of 1,2,3-tris(pentamethylcyclopentadienyl)cyclotriphosphane [(Cp*P)₃, 1 ] or 2,3,4,6-Tetrakis(pentamethylcyclopentadienyl)bicyclo[3.1.0]hexaphosphane [Cp*₄P₆, 2 ] leads in addition to the known 3,4-bis(pentamethylcyclopentadienyl)tricyclo[3.1.0.0^{2, 6}]hexaphosphane [Cp*₂P₆, 3 ] to the pentacyclic carbaphosphanes 3,4,5,6,11-pentamethyl-endo-9-pentamethylcyclopentadienyl- 3,4,5,6,11-pentacarba-pentacyclo [6.1.1^1,8.1^3,6.0^2,70^10,11]-4-en-undecaphosphane and 3,4,5,6,11-pentamethyl-exo-9-pentamethylcyclopentadienyl-3,4,5,6,11-pentacarba-pentacyclo [6.1.1^1,8.1^3,6.0^2,70^10,11]-4-en-undecaphosphane [Cp*Me₅P₆C₅, 4a, 4b ]. Furthermore, other polyphosphanes are formed, like 1,2,3,4-tetrakis(pentamethylcyclopentadienyl)cyclotetraphosphane [(Cp*P)₄, 5 ] and 2,4-bis(pentamethylcyclopentadienyl)-tetraphosphabicyclo[1.1.0]butane [(Cp*P)₂P₂, 6 ]. The structure of 4a and 4b is determined by NMR-spectroscopy. The molecule contains a P₅C₃-cunean-unit, to which a C₂Me₂-brigde and a PCp*-brigde is bonded.     

Ein neues 3-Amino-2H-azirin als Aib-Pro-Baustein: Synthese des C-terminalen Nonapeptids von Trichovirin I 1B

A New 3-Amino-2H-azirine as an Aib-Pro Synthon: Synthesis of the C-Terminal Nonapeptide of Trichovirin I 1B The synthesis of methyl N-(2,2-dimethyl-2H-azirin-3-yl)-L -prolinate ( 3 ), a novel 3-amino-2H-azirine, is described (Scheme 2). It is shown that the reaction of COCl₂ with thioamide 5 is remarkably faster than with the corresponding amide 4 , and the yield of 3 is much better in the synthesis starting with 5 . The 3-amino-2H-azirine 3 has been used as a building block of the dipeptide moieties Aib-Pro in the synthesis of nonapeptide 17 (Schemes 4 and 5), the C-terminal 6–14 segment of the peptaibole trichovirin I 1B. The structure of 17 was established by single-crystal X-ray crystallography (Figs.1 and 2).