Crystal Structures and Magnetic Properties of Charge-Transfer Salts: Cobaltocenium Bis(cis 1,2-diphenylethene-1,2-dithiolato)metalates (Metal = Ni,Pd, Pt)

Charge-transfer salts [Co(C₅H₅)₂][M(dpt)₂] (M = Ni and Pt; dpt = cis-1,2-diphenylethene-1,2-dithiolate) were synthesized and crystallographically characterized. [Co(C₅H₅)₂][Ni(dpt)2] crystallizes in the monoclinic space group C2/c with a = 25, 607(3) Å, b = 9.4151(11) Å, c = 14.407(4) Å, β = 101.373(22)°, V = 3405.3(10) Å₃ and Z = 4. [Co(C₅H₅)₂][Pt(dpt)₂] belongs to the triclinic space group $ {\rm P}\bar 1 $ with a = 9.4666(11) Å, b = 13.9869(12) Å, c = 14.2652(9) Å, α = 99.983(6)°, β = 90.034(7)°, γ = 109.751(7)°, V = 1747.2(3) ų and Z = 2. Both structures consist of ··· D⁺A^?D⁺A^?D⁺A^? ··· linear chains with the local C₅ axis of the eclipsed [Co(C₅H₅)₂]⁺ cation parallel to the best MS₄ plane of the [M(dpt)₂]^? anion. Magnetic susceptibility measurements show that χ_M T values of the complexes [Co(C₅H₅)₂][M(dpt)₂] (M = Ni, Pd, and Pt) remain nearly constant in the temperature range 15–300 K, but decrease rapidly with further decreasing of temperature, indicating weak antiferromagnetic interactions at low temperatures.     

Synthesis and Solid-State Structure of Cyclobutyltellurium(IV)-Containing Dimeric Tungstoarsenates(III)

The cage-like cyclobutyltellurium(IV)-containing tungstoarsenate(III) dimers [(C₄H₈Te-OH)₂(C₄H₈Te)₆{As₂W₁₇O₆₁(H₂O)}₂]^14? (1) and [{(C₄H₈Te)₂W₂O₅(H₂O)₂As₂W₁₉O₆₇(H₂O)}₂]^16? (2) were synthesized in moderately acidic aqueous medium by reaction of C₄H₈TeI₂ with the lacunary tungstoarsenates(III) [B-α-AsW₉O₃₃]^9? and [As₂W₁₉O₆₇(H₂O)]^14?, respectively. Polyanion 1 was isolated as a mixed cesium-guanidinium salt Cs_8.5(C(NH₂)₃)_5.5[(C₄H₈TeOH)₂(C₄H₈Te)₆{As₂W₁₇O₆₁(H₂O)}₂]·60H₂O (1a), whereas 2 crystallized as a mixed cesium-potassium salt Cs₉K₇[{(C₄H₈Te)₂W₂O₅(H₂O)₂As₂W₁₉O₆₇(H₂O)}₂]·90H₂O (2a). Single crystal X-ray analysis demonstrated that 1a and 2a crystallized in the triclinic space group \( P \bar{1} \), with a = 12.7738(8) Å, b = 18.7490(14) Å, c = 21.9831(14) Å, α = 111.155(4)^o, β = 93.312(3)^o, γ = 99.530(4) and Z = 1 for 1a and a = 19.309(6) Å, b = 24.674(8) Å, c = 26.071(8) Å, α = 63.218(17)°, β = 89.26(16)^°, γ = 79.948(17)^° and Z = 2 for 2a. The polyanion salts 1a and 2a were characterized by solid state NMR (¹H, ¹³C, ¹²⁵Te), FT-IR, TGA-DSC, and elemental analysis.     

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.     

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.     

Crystal structure,vibrational studies,optical properties,and Hirshfeld surface analysis of (C5H6N5)2[Cr2O7]

Single crystals of a new organic–inorganic compound, (C₅H₆N₅)₂Cr₂O₇ (1), adeninium dichromate, were grown by the slow evaporation technique and characterized by X-ray diffraction, infrared absorption, and the optical properties were also investigated by UV-vis absorption spectroscopy. The compound crystallizes in the triclinic system and P-1 space group with a = 11.6850(2) Å, b = 11.7531(5) Å, c = 14.5603(7) Å, α = 83.956(3)°, β = 70.481(4)°, γ = 61.863(2)°, V = 1658.70(12) Å³. The structure of the compound consists of four adeninium, (C₅H₅N₂)⁺, cations, and two dichromate dianions with all the atoms situated in general positions. Each dichromate anion is formed by two tetrahedral CrO₄ joined through shared O atoms and are linked to the cations with several weak hydrogen bonding interactions resulting in an extended network. 3-D Hirshfeld surface analysis and 2-D fingerprint plots indicate that the packing is dominated by H?O/O?H and H?N/N?H contacts.     

Tellurium-chlorine secondary interactions in palladium(II) complex of MeOC6H4TeCH2CH2NHCH(CH3)C6H4-2-OH resulting in self-assembled bimolecular aggregates with short palladium-palladium distances

A non-Schiff base (Te, N, O) ligand MeOC₆ H₄TeCH₂CH₂NHCH(CH₃)C₆H₄–2–OH (LH) having a chiral center and its palladium(II) complex [PdClL]·CH₂Cl₂ (1) have been synthesized. Both have characteristic ¹H and ¹³C NMR spectra. The single crystal structure of the complex 1 has been determined by X-ray diffraction methods. The monoclinic crystals of 1 (space group P2₁/n) have a=14.581(5) Å, b=13.160(5) Å and c=20.249(5) Å, β=99.398(5)°. The Te $\cdots A non-Schiff base (Te, N, O) ligand MeOC₆ H₄TeCH₂CH₂NHCH(CH₃)C₆H₄–2–OH (LH) having a chiral center and its palladium(II) complex [PdClL]·CH₂Cl₂ (1) have been synthesized. Both have characteristic ¹H and ¹³C NMR spectra. The single crystal structure of the complex 1 has been determined by X-ray diffraction methods. The monoclinic crystals of 1 (space group P2₁/n) have a=14.581(5) ?, b=13.160(5) ? and c=20.249(5) ?, β=99.398(5)°. The TeCl secondary interactions [3.303(2)–3.352(2) ?] between two nearly square planar palladium complex molecules results in a bimolecular aggregate having a PdPd distance 3.203(1) ?. The Pd–Te, Pd–N and Pd–O bond lengths are 2.5005(7)/2.4914(7), 2.060(4)/2.061(4) and 2.054(3)/2.044(3) ?, respectively.     

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.