[1‐Allylpyridinium][Cu2Cl3]: Synthesis,X‐ray Structure and the Regularity of Crystal Architecture of 1‐Allyl/(amino)‐pyridinium Copper(I) Chloride π‐Complexes

By alternating‐current electrochemical technique crystals of copper(I) π‐complex with 1‐allylpyridinium chloride of [C₅H₅N(C₃H₅)][Cu₂Cl₃] ( 1 ) composition have been obtained and structurally investigated. Compound 1 crystallizes in monoclinic system, space group C2/c a = 24.035(1) Å, b = 11.4870(9) Å, c = 7.8170(5) Å, β = 95.010(5)°, V = 2150.0(2) ų (at 100 K), Z = 8, R = 0.028, for 4836 independent reflections. In the structure 1 trigonal‐pyramidal environment of π‐coordinated copper(I) atom is formed by a lengthened to 1.376(2) Å C=C bond of allyl group and by three chlorine atoms. Other two copper atoms are tetrahedrally surrounded by chlorine atoms only. The coordination polyhedra are combined into an original infinite (Cu₄Cl₆^2—)_n fragment. Structural comparison of 1 and the recently studied copper(I) chloride π‐complexes with 3‐amino‐, 2‐amino‐, 4‐amino‐1‐allylpyridinium chlorides of respective [LCu₂Cl₃] ( 2 ), [L₂Cu₂Cl₄] ( 3 ), and [LCuCl₂] ( 4 ) compositions allowed us to reveal the trend of the inorganic fragment complication which depends on pKa (base) value of the corresponding initial heterocycle.     

Two Novel CuII Phenanthroline Adipato Complexes with π‐π Stacking Interactions: [Cu(phen)2(C6H8O4)] · 4.5 H2O and [(Cu2(phen)2Cl2)(C6H8O4)] · 4 H2O

The blue copper complex compounds [Cu(phen)₂(C₆H₈O₄)] · 4.5 H₂O ( 1 ) and [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)] · 4 H₂O ( 2 ) were synthesized from CuCl₂, 1,10‐phenanthroline (phen) and adipic acid in CH₃OH/H₂O solutions. [Cu(phen)₂‐ (C₆H₈O₄)] complexes and hydrogen bonded H₂O molecules form the crystal structure of ( 1 ) (P1 (no. 2), a = 10.086(2) Å, b = 11.470(2) Å, c = 16.523(3) Å, α = 99.80(1)°, β = 115.13(1)°, γ = 115.13(1)°, V = 1617.5(5) ų, Z = 2). The Cu atoms are square‐pyramidally coordinated by four N atoms of the phen ligands and one O atom of the adipate anion (d(Cu–O) = 1.989 Å, d(Cu–N) = 2.032–2.040 Å, axial d(Cu–N) = 2.235 Å). π‐π stacking interactions between phen ligands are responsible for the formation of supramolecular assemblies of [Cu(phen)₂(C₆H₈O₄)] complex molecules into 1 D chains along [111]. The crystal structure of ( 2 ) shows polymeric [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)_2/2] chains (P1 (no. 2), a = 7.013(1) Å, b = 10.376(1) Å, c = 11.372(3) Å, α = 73.64(1)°, β = 78.15(2)°, γ = 81.44(1)°, V = 773.5(2) ų, Z = 1). The Cu atoms are fivefold coordinated by two Cl atoms, two N atoms of phen ligands and one O atom of the adipate anion, forming [CuCl₂N₂O] square pyramids with an axial Cl atom (d(Cu–O) = 1.958 Å, d(Cu–N) = 2.017–2.033 Å, d(Cu–Cl) = 2.281 Å; axial d(Cu–Cl) = 2.724 Å). Two square pyramids are condensed via the common Cl–Cl edge to centrosymmetric [Cu₂Cl₂N₄O₂] dimers, which are connected via the adipate anions to form the [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)_2/2] chains. The supramolecular 3 D network results from π‐π stacking interactions between the chains. H₂O molecules are located in tunnels.     

Synthesis and Thermal Behaviour of Compounds in the System [Ph4P]Cl/BiCl3 and the Crystal Structures of [Ph4P]3[Bi2Cl9] · 2 CH2Cl2 and [Ph4P]2[Bi2Cl8] · 2 CH3COCH3

Six polynuclear chlorobismuthates are formed in the reaction between BiCl₃ and Ph₄PCl by variation of the molar ratio of the educts, the solvents and the crystallisation methods: [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂, [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃, [Ph₄P]₂[Bi₂Cl₈] · 2 CH₃COCH₃, [Ph₄P]₄[Bi₄Cl₁₆] · 3 CH₃CN, [Ph₄P]₄[Bi₆Cl₂₂], and [Ph₄P]₄[Bi₈Cl₂₈]. We report the crystal structure of [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂ which crystallises with triclinic symmetry in the S. G. P1 No. 2, with the lattice parameters a = 13.080(3) Å, b = 14.369(3) Å, c = 21.397(4) Å, α = 96.83(1)°, β = 95.96(1)°, γ = 95.94(2)°, V = 3943.9(1) ų, Z = 2. The anion is formed from two face‐sharing BiCl₆‐octahedra. [Ph₄P]₂[Bi₂Cl₈] · 2 CH₃COCH₃ crystallises with monoclinic symmetry in the S. G. P2₁/n, No. 14, with the lattice parameters a = 14.045(5) Å, b = 12.921(4) Å, c = 17.098(3) Å, β = 111.10(2)°, V = 2894.8(2) ų, Z = 2. The anion is a bi‐octahedron of two square‐pyramids, joined by a common edge. The octahedral coordination is achieved with two acetone ligands. [Ph₄P]₄[Bi₄Cl₁₆] · 3 CH₃CN crystallises in the triclinic S. G., P1, No. 2, with the lattice parameters a = 14.245(9) Å, b = 17.318(6) Å, c = 24.475(8) Å, α = 104.66(3)°, β = 95.93(3)°, γ = 106.90(4)°, V = 5486(4) ų, Z = 2. Two Bi₂Cl₈ dimers in syn‐position form the cubic anion. Lattice parameters of [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃ are also given. The solvated compounds are desolvated at approximately 100 °C. [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂ and [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃ show the same sequence of phase transitions after desolvation. All compounds melt into a liquid in which some order is observed and transform on cooling into the glassy state.     

The DMSO Solvated octahedro-[W6Cl]Cl Cluster Molecule

Octahedro-hexatungsten octadecachloride, W₆Cl₁₈, is soluble in dimethyl sulfoxide (DMSO). Brownish black crystals of W₆Cl₁₈(DMSO)₄ are formed from the brown solution by evaporation of DMSO under dynamic vacuum. The compound crystallizes monoclinically in the space group P2₁/n (no. 14) with a = 10.420 Å, b = 9.271 Å, c = 20.828 Å, β = 91.10° and Z = 2. The crystal structure is formed by isolated cluster molecules [W₆Cl]Cl of the hexameric tungsten trichloride and DMSO molecules. It is the first hierarchical variant of the tetragonal BaAl₄ type of structure where all atoms of the intermetallic phase are substituted by neutral molecules. The mean bond lengths are d(W–W) = 2.878 Å, d(W–Clⁱ) = 2.391 Å and d(W–Cl^a) = 2.447 Å. They will be discussed in relation to analogous clusters. The two crystallographically independent DMSO molecules (d(S–O) = 1.53–1.55 Å, d(S–C) = 1.65–1.78 Å) form a 3 D net of condensed < 4⁸6⁴ > dodecahedra which envelopes the clusters.     

2‐Imino‐3‐allyl‐benzothiazole as a π‐Ligand: Synthesis and Crystal Structure of [(CuCl)C10H10SN2], [C10H11SN2+]2[Cu2Cl4]2−, and [C10H11SN2+]2[Cu2Br4]2− π‐Compounds

The reaction of 2‐amino‐benzothiazole with allyl bromide resulted in a mixture of 2‐imino‐3‐allyl‐benzothiazole and 2‐imino‐3‐allyl‐benzothiazolium bromide.Using such a mixture and copper(II) chloride in acetonitrile solution in alternating‐current electrochemical synthesis crystals of the [(CuCl)C₁₀H₁₀SN₂] ( I ) have been obtained. The same procedure, performed in ethanol solution, has led to formation of [C₁₀H₁₁SN₂⁺]₂[Cu₂Cl₄]^2? ( II ). In the same manner the bromine derivative [C₁₀H₁₁SN₂⁺]₂[Cu₂Br₄]^2? ( III ) has been synthesized. All three compounds were X‐ray structurally investigated. I :monoclinic space group P2₁/n, a = 13.789(6), b = 6.297(3), c = 13.830(6) Å, β = 112.975(4)°, V = 1105.6 (9) ų, Z = 4 for CuCl·C₁₀H₁₀ SN₂ composition. Compounds II and III are isomorphous and crystallize in triclinic space group. II a = 7.377(3), b = 8.506(3), c = 9.998(4) Å, α = 79.892(10)°, β = 82.704(13)°, γ = 78.206(12)°, V = 601.9(4) ų, Z = 1. III a = 7.329(2), b = 8.766(3), c = 10.265(3) Å, α = 79.253(9)°, β = 82.625(9)°, γ = 77.963(9)°, V = 630.9(3) ų, Z = 1. In the structure I [(CuCl)C₁₀H₁₀SN₂] building blocks are bound into infinitive spiral‐like chains via strong N‐H..Cl hydrogen bonds. In the zwitter‐ionic II and III compounds copper and halide atoms form centrosymmetric [Cu₂X₄]^2? anions, which are interconnected via N‐H..X hydrogen bonds into infinite butterfly‐like chains. The strongest Cu‐(C=C) π‐interaction has been observed in structure I , where copper possesses coordination number 3. Increasing copper coordination number to 4 in II as well as replacing chlorine atoms by bromine ones in III suppresses markedly this interaction.     

Synthese und Kristallstruktur des tetrameren Nitridokomplexes [Cu(CH3CN)4]2[W4N4Cl14(CH3CN)2]

Synthesis and Crystal Structure of the Tetrameric Nitrido Complex [Cu(CH₃CN)₄]₂[W₄N₄Cl₁₄(CH₃CN)₂] . The title compound has been prepared by the reaction of CuCl with WNCl₃ in acetonitrile solution, forming red, moisture sensitive crystals. They were characterized by IR spectroscopy and by an X-ray structure determination. Space group I2/a, Z = 4, 2 027 observed unique reflections, R = 0.049. Lattice dimensions at -80°C: a = 2 527.0, b = 971.9, c = 2 137.5 pm, β = 106.01°. The compound consists of [Cu(CH₃CN)₄]⁺ ions, which are arranged to form strands, and of anions [W₄N₄Cl₁₄(CH₃CN)₂]^2?, in which the tungsten atoms were located at the vertices of a square and are linked with one another via linear W?N? W bridges. Two of the four tungsten atoms have four chlorine atoms as terminal ligands, the other two tungsten atoms have three chlorine atoms and an acetonitrile molecule as terminal ligands.     

Pr10[Si10−xAlxO9+xN17−x]Cl with x ≈ 1 – an Oxonitridoaluminosilicate Chloride

The oxonitridoaluminosilicate chloride Pr₁₀[Si_10?xAl_xO_9+xN_17?x]Cl was obtained by the reaction of praseodymium metal, the respective chloride, AlN and Al(OH)₃ with “Si(NH)₂” in a radiofrequency furnace at temperatures around 1900 °C. The crystal structure was determined by single‐crystal X‐ray diffraction (Pbam, no. 55, Z = 2,a = 10.5973(8) Å, b = 11.1687(6) Å, c = 11.6179(7) Å, R1 = 0.0337). The sialon crystallizes isotypically to the oxonitridosilicate halides Ce₁₀[Si₁₀O₉N₁₇]Br, Nd₁₀[Si₁₀O₉N₁₇]Br and Nd₁₀[Si₁₀O₉N₁₇]Cl, which represent a new layered structure type. The structure refinement was performed utilizing an O/N‐distribution model according to Paulings rules, i.e. nitrogen was positioned on all bridging sites and mixed O/Noccupation was assumed on the terminal sites resulting in charge neutrality of the compounds. The Si and Al atoms were refined equally distributed on their three crystallographic sites, due to their poor distinguishability by X‐ray analysis. The tetrahedra layers of the structure consist of condensed [(Si,Al)N₂(O,N)₂] and [(Si,Al)N₃(O,N)] tetrahedra of Q² and Q³ type. The chemical composition of the compound was derived from electron probe micro analyses (EPMA).     

Mixed Valence Tungsten (IV,V) Compounds with Layered Structures (Part IV): Syntheses,Crystal Structures,and Conductivity of BiX2[W2O2X6] (X = Cl,Br)

The reaction of metallic bismuth with either tungsten tetrachlorideoxide WOCl₄ at 650 K or tungsten tetrabromideoxide WOBr₄ at 670 K, respectively, leads to BiX₂[W₂O₂X₆] (X = Cl, Br) as black, lustrous crystal needles. The crystal structure determinations (triclinic, P$\bar{1}$ ) show the two isotypic structures to be closely related to Hg_0.55[W₂O₂Cl₆] with the presence of 1D‐polymeric W₂O₂X₆ double strands. Dinuclear [Bi₂X₄]²⁺ cations are embedded in the host structure via secondary W–X ··· Bi bonds. Unlike the other members of theM_y[W₂O₂X₆] structure family, which crystallize monoclinic and show crystallographic equivalent tungsten atoms, BiX₂[W₂O₂X₆] has independent tungsten sites. Nevertheless, an assignment of an individual oxidation state to the tungsten atoms within the W₂ group (W–W 2.8321(4) Å for X = Cl, 2.8985(4) Å for X = Br) is not possible and a dynamic intervalent state W(IV, V) is assumed. Electrical conductivity measurements for BiCl₂[W₂O₂Cl₆] show semi‐conductive behavior with a very small band gap of 70 meV and a high conductivity of around 0.5 Ω^–1cm^–1 at temperatures above 220 K. A temperature dependence of the activation energy of charge transport is present and interpreted by the Varshni model.     

Überschreitungen der konventionellen Zahl von Clusterelektronen in Metallhalogeniden des M6X12‐Typs: W6Cl18, (Me4N)2[W6Cl18] und Cs2[W6Cl18]

Beyond the Conventional Number of Electrons in M₆X₁₂ Type Metal Halide Clusters: W₆Cl₁₈, (Me₄N)₂[W₆Cl₁₈], and Cs₂[W₆Cl₁₈] Black octahedral single crystals of W₆Cl₁₈ were obtained by reducing WCl₄ with graphite in a silica tube at 600 °C. The single crystal structure refinement (space group R 3¯, Z = 3, a = b = 1498.9(1) pm, c = 845.47(5) pm) yielded the W₆Cl₁₈ structure, already reported on the basis of X‐ray powder data. (Me₄N)₂[W₆Cl₁₈] and Cs₂[W₆Cl₁₈] were obtained from methanolic solutions of W₆Cl₁₈ with Me₄NCl and CsCl, respectively. The structure of (Me₄N)₂[W₆Cl₁₈] was refined from X‐ray single crystal data (space group P 3¯m1, Z = 1, a = b = 1079.3(1) pm, c = 857.81(7) pm), and the structure of Cs₂[W₆Cl₁₈] was refined from X‐ray powder data (space group P 3¯, Z = 1, a = b = 932.10(7) pm, c = 853.02(6) pm). The crystal structure of W₆Cl₁₈ contains molecular W₆Cl₁₈ units arranged as in a cubic closest packing. The structures of (Me₄N)₂[W₆Cl₁₈] and Cs₂[W₆Cl₁₈] can be considered as derivatives of the W₆Cl₁₈ structure in which 2/3 of the W₆Cl₁₈ molecules are substituted by Me₄N⁺ ions and Cs⁺ ions, respectively. The conventional number of 16 electrons/cluster is exceeded in these compounds, with 18 electrons for W₆Cl₁₈ and 20 electrons for (Me₄N)₂[W₆Cl₁₈] and Cs₂[W₆Cl₁₈]. Cs₂[W₆Cl₁₈] exhibits temperature independent paramagnetic behaviour.     

Über Thallium(I)-chlorooxomolybdate: Synthese und Kristallstrukturen von Tl[MoOCl4(NCCH3)], Tl[Mo2O2Cl7] und Tl2[Mo4O4Cl14] und die Struktur von Tl2[MoCl6]

On Thallium(I)-oxochloromolybdates: Synthesis and Crystal Structures of Tl[MoOCl₄(NCCH₃)], Tl[Mo₂O₂Cl₇], and Tl₂[Mo₄O₄Cl₁₄] and the Structure of Tl₂[MoCl₆] Black crystals of Tl₂[MoCl₆] are formed in the reaction of TlCl with MoOCl₃ in a sealed evacuated glass ampoule at 350 °C. The crystal structure analysis shows that Tl₂[MoCl₆] (cubic, Fm 3¯m, a = 986.35(7) pm) adopts the K₂[PtCl₆] structure with a Mo–Cl bond length of 236.6 pm. Tl[MoOCl₄(NCCH₃)] was obtained by the reaction of TlCl with MoOCl₃ in acetonitrile in form of yellow, moisture sensitive crystals. The structure (orthorhombic, Cmcm, a = 746.0(1), b = 1463.8(3), c = 857.3(2) pm) is built of Tl⁺ cations and octahedral [MoOCl₄(NCCH₃)]^– anions in which the acetonitrile ligand is bound in trans position to the oxygen. The reaction of TlCl and MoOCl₃ in dichloromethane yields Tl[Mo₂O₂Cl₇] and Tl₂[Mo₄O₄Cl₁₄] as green moisture sensitive crystals. The structure of Tl[Mo₂O₂Cl₇] (orthorhombic, Pmmn, a = 694.3(1), b = 951.9(2), c = 904.7(1) pm) consists of Tl⁺ cations and dinuclear [Mo₂O₂Cl₇]^– anions, with two equidistant chlorine bridges of 248.2 and one longer chlorine bridge of 265.7 pm. The oxygen atoms are located in the trans positions of the longer chloro bridge. The structure of Tl₂[Mo₄O₄Cl₁₄] (triclinic, P1¯, a = 692.8(1), b = 919.6(1), c = 998.9(1) pm, α = 104.94(1)°, β = 90.31(1)°, γ = 108.14(1)°) is build of Tl⁺ cations and [Mo₄O₄Cl₁₄]^2– anions which form tetramers of distorted octahedral, edgesharing (MoOCl₅) units with chlorine atoms in the bridging positions. The oxygen atoms are located in the trans positions of the longest chlorine bridges.     

Hydroxo‐bridged Tetranuclear CuII Complexes: {[Cu(bpy)(OH)]4Cl2}Cl2 · 6 H2O and {[Cu(phen)(OH)]4(H2O)2}]Cl4 · 4 H2O

The blue tetranuclear Cu^II complexes {[Cu(bpy)(OH)]₄Cl₂}Cl₂ · 6 H₂O ( 1 ) and {[Cu(phen)(OH)]₄(H₂O)₂}Cl₄ · 4 H₂O ( 2 ) were synthesized and characterized by single crystal X‐ray diffraction. ( 1 ): P 1 (no. 2), a = 9.240(1) Å, b = 10.366(2) Å, c = 12.973(2) Å, α = 85.76(1)°, β = 75.94(1)°, γ = 72.94(1)°, V = 1152.2(4) ų, Z = 1; ( 2 ): P 1 (no. 2), a = 9.770(3) Å, b = 10.118(3) Å, c = 14.258(4) Å, α = 83.72(2)°, β = 70.31(1)°, γ = 70.63(1)°, V = 1252.0(9) ų, Z = 1. The building units are centrosymmetric tetranuclear {[Cu(bpy)(OH)]₄Cl₂}²⁺ and {[Cu(phen)(OH)]₄(H₂O)₂}⁴⁺ complex cations formed by condensation of four elongated square pyramids CuN₂(OH)₂L^ap with the apical ligands L^ap = Cl, H₂O, OH. The resulting [Cu₄(μ₂‐OH)₂(μ₃‐OH)₂] core has the shape of a zigzag band of three Cu₂(OH)₂ squares. The cations exhibit intramolecular and intermolecular π‐π stacking interactions and the latter form 2D layers with the non‐bonded Cl^– anions and H₂O molecules in between (bond lengths: Cu–N = 1.995–2.038 Å; Cu–O = 1.927–1.982 Å; Cu–Cl^ap = 2.563; Cu–O^ap(OH) = 2.334–2.369 Å; Cu–O^ap(H₂O) = 2.256 Å). The Cu…Cu distances of about 2.93 Å do not indicate direct interactions, but the strongly reduced magnetic moment of about 2.74 B.M. corresponds with only two unpaired electrons per formula unit of 1 (1.37 B.M./Cu) and obviously results from intramolecular spin couplings (χ_m(T‐θ) = 0.933 cm³ · mol^–1 · K with θ = –0.7 K).     

Unique Isle Anion [Cu6Cl10]4- in π-Complex of Cu(I) Chloride with 1-(2-Pyridyl)-4-allyl-piperazinium. Synthesis and crystal structure of [(C5H4NH)NC4H8NH(C3H5]2+[Cu3Cl5]2-

Single crystals of [(C₅H₄NH)NC₄H₈NH(C₃H₅)]²⁺[Cu₃Cl₅]^2? are obtained by ac synthesis in ethanol from 1-(2-pyridyl)-4-allyl-piperazinium and Cu(II) dichlorides and their structure is studied by X-ray diffraction analysis (space group P-1, a = 7.246(7) Å, b = 8.54(1) Å, c = 16.41(1) Å, α = 70.76(8)°, β = 77.24(8)°, λ = 80.42(9)°, V = 30(4) ų, Z = 2, R(F) = 0.0686. In the structure of this π-complex, the Cu and Cl atoms form unusual centrosymmetrical Cu₆Cl₁₀ fragments, each fragment being bonded to two 1-(2-pyridyl)-4-allyl-piper-azinium cations via π-interaction Cu-(C=C). A three-dimensional structure is formed by means of N-H…Cl hydrogen bonds. The trigonal-pyramidal surrounding of the Cu(1) atom includes three Cl atoms and the C=C bond, while the tetrahedral surrounding of Cu(2) and the trigonal surrounding of Cu(3) involve the Cl atoms only.     

Synthesis,Crystal Structures,and Nonlinear Optical Properties of Two Cubane‐Like Cluster Compounds [(n‐Bu)4N]3[MoS4Ag3Cl4] and [Et4N]3[WOS3Cu3I4]

The compounds [(n‐Bu)₄N]₃[MoS₄Ag₃Cl₄] ( 1 ) and [Et₄N]₃[WOS₃Cu₃I₄] ( 2 ) were synthesized and characterized. Compound 1 crystallizes in the rhombohedral system, space group R3c with a = 17.194(1), b = 17.194(1), c = 39.194(3)Å, Z = 6, V = 10034.7(11)ų. Compound 2 crystallizes in the rhombohedral system, space group R3c with a = 14.461(2), b = 14.461(2), c = 34.952(2)Å, Z = 6, V = 6329.9(13)ų. The X‐ray crystallographic structure determinations show that these two cluster compounds consist of a slightly distorted cubic core. Nonlinear optical (NLO) properties of these two clusters were investigated by using Z‐scan techniques with an 8 ns pulsed laser at 532 nm; both clusters exhibit strong nonlinear optical absorption effect (effective α₂ = 1.18 × 10^—10 m · W^—1 for 1 and 1.0 × 10^—10 m · W^—1 for 2 ).     

Two Modifications of Copper(I) Octahedro-Hexatungsten(II) Tetradecabromide,Cu2[W6Br14]

The reaction of W₆Br₁₂ with CuBr sealed in an evacuated silica tube at the temperature gradient 925/915 K and annealing at 625/300 K yields a mixture of orthorhombic α-Cu₂[W₆Br₁₄] and cubic β-Cu₂[W₆Br₁₄] in the low temperature zone. α-Cu₂[W₆Br₁₄] crystallizes in the space group Pbca (no. 61), a = 15.126 Å, b = 9.887 Å, c = 15.954 Å, Z = 4, oP88, and β-Cu₂[W₆Br₁₄] crystallizes in the space group Pn3 (no. 201), a = 13.391 Å, Z = 4, cP88. The crystal structures are built up by [(W₆Br)Br]^2– cluster anions and Cu⁺ cations. The cluster anions show only in the peripheral shells small deviation from m3m symmetry (d(W–W) = 2.630 Å; d(W–Brⁱ) = 2.618 Å; d(W–Br^a) = 2.614 Å). The anions are arranged in a slightly compressed bcc pattern (α) and ccp (β) pattern, respectively. The Cu⁺ cations are trigonal-planar coordinated by Br^a ligands with d(Cu–Br) = 2.377 Å (α) and 2.378 Å (β). The cubic β-modification is diamagnetic with an unexpected large susceptibility (χ_mol = –884 × 10^–6 cm³ mol^–1) and have a band gap of 2.8 eV. It decomposes under dynamic vacuum in two steps at 795 K und 1040 K.     

On the Crystal Structure of K2Cu5Cl8(OH)4·2H2O

Single crystals of K₂Cu₅Cl₈(OH)₄·2H₂O were grown using hydrothermal techniques. The compound is monoclinic with a = 11.6424(11), b = 6.5639(4), c = 11.7710(10)Å, β = 91.09(1)°, V = 899.4(2)ų, space group P2₁/c, Z = 2. The crystal structure was determined using single crystal X‐ray diffraction data and refined to a residual of R(|F|) = 0.025 for 1208 independent observed reflections with I > 2σ(I). Two out of three crystallographically independent Cu atoms are coordinated to four near hydroxyl groups or chlorine atoms and two more distant Cl atoms, giving an octahedrally Jahn‐Teller distorted (4+2)‐configuration. For the remaining third copper cation a square‐planar coordination can be found. Edge‐sharing of the octahedra results in the formation of kagome‐type sheets parallel to (100). The octahedral layers are decorated on both sides by planar [Cu(OH)₂Cl₂]‐units around the third Cu atom. The K atoms are located between adjacent sheets and are surrounded by six Cl atoms as well as two water molecules. The coordination polyhedra about the K‐atoms can be described as distorted bicapped trigonal prisms. Additional linkage is provided by intra‐ as well as inter‐layer hydrogen bonds (O—H···Cl, O—H···O).     

X‐ray Investigation and Coordination Behaviour of the 1,3‐Diallylbenzimidazolium Cation in [C13H15N2]+2 [CuCl2.58Br1.42]2– and [C13H15N2]+[Cu2Cl0.67Br2.33]– Complexes

By means of alternating current electrochemical synthesis crystals of [C₁₃H₁₅N₂]⁺₂[CuCl_2.58Br_1.42]^– ( I ) and [C₁₃H₁₅N₂]⁺[Cu₂Cl_0.67Br_2.33]^– ( II ) have been obtained and structurally characterized. Compound I crystallizes in the orthorhombic system, space group Fddd, a = 7.828(1) Å, b = 26.402(2) Å, c = 28.595(3) Å, D_c = 1.4995(5) g/cm³, Z = 8, R = 0.067 for 2157 reflections. The CuX₄^2– tetrahedra are connected with the organic cations through an electrostatic interaction. Crystals of II are monoclinic, space group P2₁/c, a = 9.2293(8) Å, b = 22.1332(9) Å, c = 9.2939(9) Å, β = 118.021(4)°, D_c = 2.1251(5) g/cm³, Z = 4, R = 0.042 for 2858 reflections. A tetrahedral environment of the Cu1 atom involves four halide atoms, whereas Cu2 possesses a trigonal‐pyramidal coordination with the C=C‐bond and three halide atoms.     

Synthesen,Eigenschaften und Kristallstrukturen der Cluster‐Salze Bi6[PtBi6Cl12] und Bi2/3[PtBi6Cl12]

Syntheses, Properties and Crystal Structures of the Cluster Salts Bi₆[PtBi₆Cl₁₂] and Bi_2/3[PtBi₆Cl₁₂] Melting reactions of Bi with Pt and BiCl₃ yield shiny black, air insensitive crystals of the subchlorides Bi₆[PtBi₆Cl₁₂] and Bi_2/3[PtBi₆Cl₁₂]. Despite the substantial difference in the bismuth content the two compounds have almost the same pseudo‐cubic unit cell and follow the structural principle of a CsCl type cluster salt. Bi₆[PtBi₆Cl₁₂] consists of cuboctahedral [PtBi₆Cl₁₂]^2? clusters and Bi₆²⁺ polycations (a = 9.052(2) Å, α = 89.88(2)°, space group P 1, multiple twins). In the electron precise cluster anion, the Pt atom (18 electron count) centers an octahedron of Bi atoms whose edges are bridged by chlorine atoms. The Bi₆²⁺ cation, a nido cluster with 16 skeletal electrons, has the shape of a distorted octahedron with an opened edge. In Bi_2/3[PtBi₆Cl₁₂] the anion charge is compensated by weakly coordinating Bi³⁺ cations which are distributed statistically over two crystallographic positions (a = 9.048(2) Å, α = 90.44(3)°, space group ). Bi₆[PtBi₆Cl₁₂] is a semiconductor with a band gap of about 0.1 eV. The compound is diamagnetic at room temperature though a small paramagnetic contribution appears towards lower temperature.     

The Mixed Valence Tungsten(IV,V) Compound Na[W2O2Br6]

The reaction of W₆Br₁₂, NaBr, and WO₂Br₂ in the presence of Br₂ in a sealed silica tube yields Na[W₂O₂Br₆] together with WOBr₄ and WO₂Br₂ in the low temperature zone (temperature gradient 1030/870 K). Na[W₂O₂Br₆] crystallizes orthorhombically in the space group Immm (no. 71) with a = 3.775 Å, b = 10.400 Å, c = 13.005 Å and Z = 2. Pairs of condensed trans-[WO₂Br₄] octahedra with a common Br₂ edge form along [100] double chains [W₂O_4/2Br₆]^1– via the oxygen atoms. The mixed valent tungsten atoms are bonded to W₂ pairs with a 2 c–3 e bond (d(W–W) = 2.946 Å, d(W–O) = 1.888 Å, d(W–Br^b) = 2.537 Å, d(W–Br^t) = 2.535 Å, ∢O–W–O = 177.4°, ∢Br^b–W–Br^b (endocyclic) = 109.0°). The Na⁺ cations connect the anionic double chains to form two-dimensional layers parallel (001), which interact by van der Waals forces. The cations are eightfold coordinated by a cube of the terminal Br^t ligands of the polymeric anions (d(Na–Br) = 3.138 Å). Na[W₂O₂Br₆] may be discussed as an intercalation compound of the oxide bromide WOBr₃.     

Alkalimetallnitrido‐tecto‐metallate(VI) mit Netzwerken von Sechsringen spitzenverknüpfter Tetraeder [(MNN3/2)6] mit M = Mo,W der unerwarteten Zusammensetzung A9+x[M6N15] mit A = Rb,Cs und 0 < x < 1

Alkali Metal Nitrido Tecto Metallates(VI) with Networks of Six‐membered Rings of Corner‐sharing Tetrahedra [(MNN_3/2)₆] with M = Mo, W of the Unexpected Composition A_9+x[M₆N₁₅] with A = Rb, Cs and 0 < x < 1 Reactions of metal powders of Mo and W respectively with amides and azides of Rb and Cs lead to the compounds Rb_9+x[W₆N₁₅] and Cs_9+x[M₆N₁₅] with M = Mo, W and 0 < x < 1. The reactions are carried out at 650 °C in autoclaves for salt melts and are finished within 5 d. Crystals of the compounds are embedded in a matrix of the corresponding alkali metal. These metals result from the thermal decomposition of the amides and azides used in high molar ratios. The metals are washed out by liquid ammonia. Besides microcrystalline material of the above mentioned compounds single crystals suitable in size for x‐ray structure determinations were isolated. The compounds crystallize in the space group R3c (No. 167) with Z = 6 and the following lattice constants: Rb_9+x[W₆N₁₅]: a = 12.743(7) Å, c = 27.794(8) Å, c/a = 2.181 Cs_9+x[Mo₆N₁₅]: a = 13.104(5) Å, c = 28.430(9) Å, c/a = 2.170 Cs_9+x[W₆N₁₅]: a = 13.136(5) Å, c = 28.472(6) Å, c/a = 2.167 The metal centres of tetrahedra [MNN_3/2] are condensated to cyclohexane analogue six‐membered rings in chair‐form via nitrogen atoms and axial ones connect them to a three‐dimensional network. Nine – as to the formula unit – of the alkali metal atoms are located in vacancies of the anionic partial structure. The residual atoms with 0 < x < 1 centre the six‐membered rings and are coordinated planar hexagonal by N neighbours.     

Syntheses and Structures of two 1‐D Complexes, [Co(dmf)2(NCNCN)2] and [Cu(bipy)(NCNCN)]ClO4 with Bridging Dicyanamide Ligands

Two novel dicyanamide complexes [Co(dmf)₂(NCNCN)₂] ( 1 ) and [Cu(bipy)(NCNCN)]ClO₄ ( 2 ) have been synthesized and structurally characterized. 1 crystallizes in the monoclinic space group C2 with a = 13.568(6)Å, b = 7.403(3)Å, c = 8.118(3)Å and Z = 2, whereas 2 crystallizes in the monoclinic system, Cc group, a = 14.270(7)Å, b = 9.143(5)Å, c = 12.371(1) Å, β = 118.612(7)°, and Z = 4. According to X‐ray crystallographic studies, in complex 1 each Co^II ion is six‐coordinated with four nitrogen atoms from four μ_{1, 5}‐dca (dca = dicyanamide) ligands and two oxygen atoms from two dmf ligands to form distorted octahedra. 1 forms a 1‐D network bridged via μ_{1, 5}‐dca. 2 consists of a uniform Cu(NCNCN)Cu chain, each Cu^II ion is octahedrally coordinated with four nitrogen atoms from two μ_{1, 5}‐dca ligands and one bipy ligand and two oxygen atoms from two ClO₄^— ions. The octahedral Cu^II ion shows a significant Jahn‐Teller distortion, with two axial oxygen atoms considerably farther from the copper than the four equatorial nitrogens.