Synthese,Eigenschaften und Struktur von LiAuI4 und KAuI4 mit einer Diskussion der kristallchemischen Verwandtschaft zwischen den Halogenoauraten RbAuCl4, AgAuCl4, RbAuBr4 und LiAuI4

Synthesis, Properties, and Structure of LiAuI₄ and KAuI₄ with a Discussion of the Crystal Chemical Relationship between the Halogenoaurates RbAuCl₄, AgAuCl₄, RbAuBr₄ and LiAuI₄ The alkalimetal iodo aurates(III) MAuI₄ (M ? Li, K) are obtained in form of single crystals from MI, Au and I₂ in a sealed glass ampoule by heating to 550°C and slow cooling to 300°C. KAuI₄ crystallizes in the monoclinic space group P2₁/c with a = 968.6(4); b = 704.5(2), c = 1393.2(7) pm; β = 100.95(2)° and Z = 4. The crystal structure is built up from square planar AuI₄^? anions and K⁺ cations. The cations are coordinated by eight I atoms of neighbouring AuI₄^? anions with distances K? I between 350.0 and 369.6 pm. At 100°C KAuI₄ is reduced to form K₃Au₃I₈, which at 180°C decomposes to KI, Au and I₂ LiAuI₄ forms black, moisture sensitive needles, decomposing in the absence of iodine at 20°C to LiI, Au and I₂. It crystallizes in a variant of the RbAuBr₄ type structure with the space group P2₁/a and a = 1511.7(4); b = 433.9(4); c = 710.0(2) pm; β = 121.50(2)°; Z = 2. The crystal chemical relationship between the structures of RbAuCl₄, RbAuBr₄, AgAuCl₄ and LiAuI₄ is discussed.     

Syntheses,Structures, and Properties of New Quaternary Gold-Chalcogenides: K2Au2Ge2S6, K2Au2Sn2Se6, and Cs2Au2SnS4

The new compounds K₂Au₂Ge₂S₆ ( 1 ), K₂Au₂Sn₂Se₆ ( 2 ), and Cs₂Au₂SnS₄ ( 3 ) have been synthesized through direct reaction of the elements with a molten polyalkalithiogermanate(stannate) flux at 650, 550, and 400 °C, respectively. Their crystal structures have been determined by single crystal X-ray diffraction techniques. 1 crystallizes in the monoclinic space group P2₁/n with a = 10.633(2) Å, b = 11.127(2) Å, c = 11.303(2) Å, β = 115,37(3)°, V = 1208,2(3) ų and Z = 4, final R(Rw) = 0.045(0.106). 2 crystallizes in the tetragonal space group P4/mcc with a = 8.251(1) Å, c = 19.961(4) Å, V = 1358,9(4) ų and Z = 4, final R(Rw) = 0.040(0.076). 3 crystallizes in the orthorhombic space group Fddd with a = 6.143(1) Å, b = 14.296(3) Å, c = 24.578(5) Å, V = 2158.4(7) ų and Z = 4, final R(Rw) = 0.039(0.095). The structures of 1 , 2 , and 3 consist of infinite, one-dimensional anionic chains containing X₂Q₆^4– units linked by Au⁺ ions and charge balancing K⁺/Cs⁺ ions situated between the chains. All compounds were investigated with differential thermal analysis, FT-IR, and solid state UV/VIS diffuse reflectance spectroscopy.     

Cubic Phase Formation from New Hexacatenar Metallomesogens Based on Cobalt 3,4,5‐Trialkoxybenzoate

Cobalt complexes of Co(3Cn)₂(MeOH)₄, derived from 3,4,5‐trialkyloxybenzoate ligand (noted as 3Cn) with n = 10, 12, 14 and 16, were synthesized and characterized. The crystal of Co(1C₁₂)₂(MeOH)4 were determined by means of x‐ray single crystal analysis. It crystallizes in the monoclinic P21/c space group with a = 24.3271(19) Å, b = 14.0058(11) Å, c = 6.4612(4) Å, α = γ = 90o, β = 94.368(4)o, and Z = 2. The phase texture and mesogenic properties were detected by polarized optical microscopic and powder x‐ray diffraction technique. It was found that these compounds display the cubic phases. Differential scanning calorimetric data indicated that these compounds were nearly room temperature liquid crystalline and with a very wide mesogenic phase range.     

Crystal Structures of Chiral Ionophores: Bis(9,9′-spirobifluorene)-26-crown-4 and -32-crown-6

The X-ray crystal structures of bis(9,9′-spirobifluorene)-26-crown-4βbenzene solvate (monoclinic, a = 15.47 Å, b 11.265 Å, c = 15.220 Å, β = 91.54°, space group C2) and bis(9,9′-spirobifluorene)-32-crown-6·dichloromethane solvate (tetragonal, a = 20.958 Å, c = 11.779 Å, space group P4₁2₁2) are described. Both compounds act as enantioselective ionophores for α-aminoalcohols.     

The antiferromagnetic structures of KFeS2, RbFeS2, KFeSe2, and RbFeSe2 and the correlation between magnetic moments and crystal field calculations

The ternary compounds KFeS₂, RbFeS₂, KFeSe₂, and RbFeSe₂ were prepared and their crystal structures were determined from single-crystal diffractometer data. The atomic arrangement in the isotypic compounds (space group C2/c) is characterized by tetrahedra of chalcogen atoms. Those tetrahedra are centered by iron ions and linked by edges, thus forming chains of ¹_∞[FeX⁻_4/2] frameworks (X S or Se). Susceptibility measurements are reported. Neutron difraction experiments on powdered samples revealed magnetic structures in the antiferromagnetically ordered state. The magnetic moments of the iron ions shows a significant dependence of the atomic arrangement. Therefore calculations based on a simple point charge model are discussed to correlate the magnetic moments and crystal field splittings.     

Crystallochemistry of the novel two-layer RECuMg4 (RE=La, Tb) ternary compounds

The crystal structures of the new ternary compounds LaCuMg₄ and TbCuMg₄ were studied by X-ray powder diffraction and single-crystal methods, respectively. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDXS) was used for examining microstructure and phase composition. LaCuMg₄ crystallizes in the UCoAl₄ structure type (space group P6¯2m, Pearson code hP18, a=1.03911(1), c=0.45126(1) nm, Z=3, R_F=0.0654), while TbCuMg₄ exhibits a new structure (space group Cmmm, Pearson code oS48, a=1.35797(6), b=2.03333(9), c=0.39149(2) nm, Z=8, wR₂=0.0426). Both structures represent a family of two-layer compounds. All interatomic distances indicate metallic type bonding. The structural peculiarities of these compounds and their relations are discussed.     

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.     

Rare earth substituted fluoride-phosphate apatites

Compositions with the general formula Ln_xM_10?2xNa_x(PO₄)₆F₂ (Ln = La, Pi, Nd, Sm, Eu, Dy, Er, Lu, andY;M = Ca, Sr, and Ba) have been prepared and studied by X-ray diffraction methods. The hexagonal apatite like structure was indicated by the powder patterns of all the compounds (with Ba compounds only when Ln = La through Sm). Single crystal precession data reveal that the crystal lattice of all the compositions in the Ca and Sr system have space group P6₃/m, the Ln₂Ba₆Na₂(PO₄)₆F₂ compounds crystallize in space group P6 and the Ln₃Ba₄Na₃(PO₄)₆F₂ compounds in the trigonal space group P3. Order and disorder mechanisms of the substitution and its dependence on size and polarization effects are discussed.     

Synthesis and Crystal Structures of Bis(tetraethylammonium)(2-oxo-1,3-dithiole-4,5-dithiolato)zincate(II) and Bis(tetra-n-butylammonium)(2-oxo-1,3-dithiole-4,5-dithiolato)zincate(II)

The title compounds were prepared from 1,3,4,6-tetrathiapentalene-2,5-dione ( 1 ) in one step via the in situ generated intermediate 2-oxo-1,3-dithiole-4,5-dithiolate (dmid; 2 ). The X-ray single crystal structure of (Et₄N)₂[Zn(dmid)₂] ( 3 a ) gave the tetragonal space group P4₃2₁2 with a = b = 13.810(2) Å, c = 16.480(3) Å, and Z = 4. (n-Bu₄N)₂[Zn(dmid)₂] ( 3 b ) gave the triclinic space group P 1 with a = 11.947(4) Å, b = 14.665(5) Å, c = 16.662(8) Å, α = 100.21(3)°, β = 104.46(3)°, γ = 110.73(3)°, and Z = 2.     

Die Kristallpackung in drei Modifikationen von PPh4[ReO(S4)2] und PPh4[ReS(S4)2]

The Crystal Packing in three Modifications of PPh₄[ReO(S₄)₂] and PPh₄[ReS(S₄)₂] Mixed crystals PPh₄[ReS(S₄)₂]_0,63[ReO(S₄)₂]_0,37 were obtained from PPh₄Cl, ReCl₅ and Na₂S₄ in acetonitrile. Their crystal structure corresponds to the known structure of this kind of compound (space group P2₁/n). In a similar reaction with ReBr₅ instead of ReCl₅, PPh₄[ReO(S₄)₂] was obtained in small yield. Its triclinic crystal structure was determined by X‐ray crystallography (space group P1). It contains cation pairs (PPh₄⁺)₂ such as they have been found in many other instances. In contrast, the crystal structures of the mixed crystals and of one known modification of PPh₄[ReS(S₄)₂] have PPh₄⁺ columns similar to compounds crystallizing in the space group P4/n, albeit in a severely distorted manner; their space group P2₁/n is a subgroup of P4/n with a doubled unit cell. In another modification of PPh₄[ReS(S₄)₂] (space group P2₁/c) the columns are less distorted, but arranged in a different way.     

Ln2(ClO4)2(H2I2O10) · 8H2O (Ln = Sm,Gd), a Lanthanide Perchlorate Mesodiperiodate forming a Novel Layer Structure

By slow evaporation of solutions containing Ln(ClO₄)₃ (Ln = Sm, Gd), H₅IO₆ and an excess of HClO₄, crystals of the title compounds could be obtained. Their structures were determined by single‐crystal X‐ray diffraction. The compounds crystallize in the monoclinic crystal system, space group P2₁/c. They contain Ln³⁺ ions, which are coordinated by [H₂I₂O₁₀]^4— anions forming two‐dimensional, cationic networks. These are separated by perchlorate ions, forming a layered structure.     

Form III of 2,2′,4,4′,6,6′‐hexanitro­azobenzene (HNAB‐III)

The crystal structure of form III of the title compound, HNAB [systematic name: bis(2,4,6‐trinitro­phenyl)diazene], C₁₂H₄N₈O₁₂, has finally been solved as a pseudo‐merohedral twin (monoclinic space group P2₁, rather than the ortho­rhombic space group C222₁ suggested by diffraction symmetry) using a dual space recycling method. The significant differences in the room‐temperature densities of the three crystalline forms allow examination of molecular differences due to packing arrangements. An interesting relationship with the stilbene analog, HNS, is discussed. Interatomic separations are compared with other explosives and/or nitro‐containing compounds.     

Crystal structure of the pyrovanadate K4V2O7

The crystal structure of anhydrous K₄V₂O₇ (I) is determined by powder X-ray diffraction. The compound crystallizes in the monoclinic system (a = 10.222(1) Å, b = 6.2309(8) Å, c = 7.282(1) Å, β = 101.31(1)°, space group C2/m, Z = 2). The structure contains layers of isolated V₂O₇ pyrovanadate groups separated by layers of potassium cations. The hydration and dehydration of I are studied by thermal analysis and high-temperature X-ray diffraction. The dehydration is accompanied by decomposition of the starting crystal hydrate to give intermediate compounds. Anhydrous compound I undergoes a reversible phase transition at 740°C. The high-temperature phase is assumed to have a hexagonal unit cell (a = 6.169(4) Å, c = 15.72(1) Å, Z = 2).     

Preparation,Crystal Structure,Physical Properties and Electronic Band Structure of TlScQ2 (Q = S,Se and Te)

The title compounds were prepared by reaction of Tl₂Q (Q = S, Se and Te) Sc and Q in the temperature range of 200 to 500 °C. The structures of the selenide and the telluride adopt the α‐NaFeO₂ type, while TlScS₂ crystallizes in the β‐RbScO₂ type structure. The space group is for TlScSe₂ and TlScTe₂ with a = 3.9370(4) Å, c = 23.194(5) Å, and a = 4.2129(4) Å, c = 24.099(3) Å, respectively. The sulphide crystallizes in P6₃/mmc with a = 3.761(3) Å and c = 14.942(4) Å. The crystal chemical relations between the three chalcogenides are discussed. According to the electrical measurements and the band structure calculations, the compounds are semiconductors or poor metals.     

Synthese und Kristallstrukturen der Calcium‐Iridiumsilicide Ca3Ir4Si4 und Ca2Ir2Si

Synthesis and Crystal Structures of the Calcium Iridium Silicides Ca₃Ir₄Si₄ and Ca₂Ir₂Si The new compounds Ca₃Ir₄Si₄ und Ca₂Ir₂Si were prepared by reaction of the elemental components in sealed tantalum ampoules at 1200 °C. Their structures were determined from X‐ray single crystal data. Ca₃Ir₄Si₄(cubic, space group I4¯3m, a = 7.4171(2)Å, Z = 2) crystallizes with the Na₃Pt₄Ge₄ type structure. For Ca₂Ir₂Si (monoclinic, space group C2/c, a = 9.6567(5)Å, b = 5.8252(2)Å, c = 7.3019(4)Å, β = 100.212(2)°, Z = 4) a new structure was found. Chains of edge sharing, heavily distorted SiIr₄‐tetrahedra (Ir‐Si: 2.381 and 2.414Å) are connected via short Ir—Ir‐contacts (2.640Å) to form an open Ir/Si‐framework accommodating a three‐dimensional arrangement of calcium atoms (Ca—Ca: 3.413 ‐ 3.948Å).     

Crystal structure and magnetic properties of Co2TeO3Cl2 and Co2TeO3Br2

The crystal structures of the two new synthetic compounds Co₂TeO₃Cl₂ and Co₂TeO₃Br₂ are described together with their magnetic properties. Co₂TeO₃Cl₂ crystallize in the monoclinic space group P2₁/m with unit cell parameters a=5.0472(6) Å, b=6.6325(9) Å, c=8.3452(10) Å, β=105.43(1)°, Z=2. Co₂TeO₃Br₂ crystallize in the orthorhombic space group Pccn with unit cell parameters a=10.5180(7) Å, b=15.8629(9) Å, c=7.7732(5) Å, Z=8. The crystal structures were solved from single crystal data, R=0.0328 and 0.0412, respectively. Both compounds are layered with only weak interactions in between the layers. The compound Co₂TeO₃Cl₂ has [CoO₄Cl₂] and [CoO₃Cl₃] octahedra while Co₂TeO₃Br₂ has [CoO₂Br₂] tetrahedra and [CoO₄Br₂] octahedra. The Te(IV) atoms are tetrahedrally [TeO₃E] coordinated in both compounds taking the 5s² lone electron pair E into account. The magnetic properties of the compounds are characterized predominantly by long-range antiferromagnetic ordering below 30 K.     

Bildung siliciumorganischer Verbindungen, 47. Die Kristall- und MolekülStruktur von 1,3,5,7- Tetramethyl-tetrasila-adamantan

Formation of organosilicon compounds. 47. The crystal land molecular structure of 1,3,5,7-tetramethyl-tetrasila-adamantan 1,3,5,7- Tetramethyl-tetrasila-adamantan, Si₄C₁₀H₂₄, is a pyrolysis product of Si(CH₃)₄. It crystallizes in the monoclinic space group P2₁/c with a = 8.859 Å, b = 9.844 Å, c = 18.316 Å, β = 91.04°, Z = 4. The molecule exhibits T_d-symmetry within the experimental error. The mean bond lengths Si? C are 1.889 Å and 1.866 Å for the Si? CH₃ and Si? CH₂ bonds respectively.     

Syntheses and Crystal Structures of the Novel Ternary Thioborates Na3BS3, K3BS3, and Rb3BS3

The orthothioborates Na₃BS₃, K₃BS₃ and Rb₃BS₃ were prepared from the metal sulfides, amorphous boron and sulfur in solid state reactions at temperatures between 923 and 973 K. In a systematic study on the structural cation influence on this type of ternary compounds, the crystal structures were determined by single crystal X‐ray diffraction experiments. Na₃BS₃ crystallizes in the monoclinic space group C2/c (No. 15) with a = 11.853(14) Å, b = 6.664(10) Å, c = 8.406(10) Å, β = 118.18(2)° and Z = 4. K₃BS₃ and Rb₃BS₃ are monoclinic, space group P2₁/c (No. 14) with a = 10.061(3) Å, b = 6.210(2) Å, c = 12.538(3) Å, β = 112.97(2) and a = 10.215(3) Å, b = 6.407(1) Å, c = 13.069(6) Å, β = 103.64(5)°, Z = 4. The potassium and rubidium compounds are not isotypic. All three compounds contain isolated [BS₃]^3– anions with boron in a trigonal‐planar coordination. The sodium cations in Na₃BS₃ are located between layers of orthothioborate anions, in the case of K₃BS₃ and Rb₃BS₃ stacks of [BS₃]^3– entities are connected via the corresponding cations. X‐ray powder patterns were measured and compared to calculated ones obtained from single crystal X‐ray structure determinations.     

Synthesis and Structure of Ln2(H4IO6)(I2O10)·H3O·5 H2O (Ln=Pr,Nd, Sm), a Lanthanide Periodate Diperiodate

By slow evaporation of solutions containing Ln(ClO₄)₃ (Ln=Pr, Nd, Sm), H₅IO₆ and an excess of HClO₄, crystals of the title compounds could be obtained. Their structures were determined by single‐crystal X‐ray diffraction. The compounds crystallize in the monoclinic crystal system, space group I2/a. They contain two types of periodate ions: octahedral H₄IO₆ groups and two crystallographically different I₂O₁₀ groups, which consist of two edge‐sharing octahedra. These anions coordinate to the cations as bridging groups yielding a three‐dimensional network. Together with some water of crystallization, a coordination number of 9 is achieved around the lanthanide ions with a tri‐capped trigonal prismatic geometry.     

The preparation and crystal structures of BiReO4 and BiRe2O6

The crystal structures of two new oxides, BiReO₄ and BiRe₂O₆, have been determined by single-crystal X-ray methods using an Enraf-Nonius CAD-4F diffractometer. BiReO₄ crystallizes as red metallic needles in the space group Cmcm, cell dimensions a = 3.839(1) Å, b = 14.914(2) Å, c = 5.534(1) Å, Z = 4. The structure consists of sheets of corner-shared octahedra (composition ReO₄) linked by Bi atoms (R = 2.55%). BiRe₂O₆ crystallizes as black metallic plates in the space group C2/m, cell dimensions a = 5.516(1) Å, b = 4.906(1) Å, c = 8.384(1) Å, β = 106.71(1)°, Z =2. The structure consists of layers containing Re₂O₁₀ units linked together by corner sharing of the octahedra, alternating with layers of Bi atoms (R = 2.61%). The structure is disordered due to the random stacking of the Re layers. The Re---Re distance of 2.5 Å in the Re₂O₁₀ unit is comparable to that found in similar compounds. Both compounds exhibit stereochemically active lone pairs.