Palladium clusters Pd<Subscript>4</Subscript>(SR)<Subscript>4</Subscript>(OAc)<Subscript>4</Subscript> and Pd<Subscript>6</Subscript>(SR)<Subscript>12</Subscript> (R = Bu,Ph): Structure and properties

The structures of the Pd₄(SBu)₄(OAc)₄ (I) and Pd₆ (SBu)₁₂ (II) palladium clusters are determined by the X-ray diffraction method. For cluster I: a = 8.650(2), b = 12.314(2), c = 17.659(4) Å, α = 78.03(3)°, β = 86.71(2)°, γ = 78.13(3)°, V = 1800.8(7) ų, ρcalcd = 1.878 g/cm³, space group P \(\bar 1\), Z = 4, N = 3403, R = 0.0468; for structure II: a = 10.748(2), b = 12.840(3), c = 15.233(3) Å, α = 65.31(3)°, β = 70.10(3)°, γ = 72.91(3)°, V = 1767.4(6) ų, ρ calcd = 1.605 g/cm³, space group P \(\bar 1\), Z = 1, N = 3498, R = 0.0729. In cluster I, four Pd atoms form a planar cycle. The neighboring Pd atoms are bound by two acetate or two mercaptide bridges (Pd…Pd 2.95–3.23 Å, Pd…Pd angles 87.15°–92.85°). In cluster II, the Pd atoms form a planar six-membered cycle with Pd···Pd distances of 3.09–3.14 Å, the PdPdPd angles being 118.95°–120.80°. The Pd atoms are linked in pairs by two mercaptide bridges. The formation of clusters I and II in solution is proved by IR spectroscopy and calorimetry. Analogous clusters are formed in solution upon the reaction of palladium(II) diacetate with thiophenol.     

Synthesis and X-ray investigation of Rb<Subscript>2</Subscript>[Pd(NO<Subscript>3</Subscript>)<Subscript>4</Subscript>] and Cs<Subscript>2</Subscript>[Pd(NO<Subscript>3</Subscript>)<Subscript>4</Subscript>]

Powder and single crystal X-ray diffraction studies have been performed for anhydrous nitrate complexes Rb₂[Pd(NO₃)₄] (I) and Cs₂[Pd(NO₃)₄] (II). Crystal data for I: a = 7.843(1) Å, b = 7.970(1) Å, c = 9.725(1) Å; β = 100.39(1)°, V = 597.9(1) Å ³, space group P2₁/c, Z = 2, d _calc = 2.918 g/cm³; for II: a = 10.309(2) Å, b = 10.426(2) Å, c = 11.839(2) Å; β = 108.17(3)°, V = 1209.0(4) ų, space group P2₁/c, Z = 4, d ^calc = 3.408 g/cm³. The structures are formed by isolated [Pd(NO₃)₄]^2? complex anions and alkali metal cations. The plane-square environment of the Pd atom is formed from the oxygen atoms of the monodentate nitrate groups. The geometrical characteristics of the complex anions are analyzed. Compound II has a short contact Pd...Cs 3.252 Å.     

Crystal structures of <Emphasis Type="Italic">trans</Emphasis>-[Re<Subscript>6</Subscript>S<Subscript>8</Subscript>(CN)<Subscript>2</Subscript>L<Subscript>4</Subscript>] complexes,L = pyridine or 4-methylpyridine

The structures of three novel octahedral rhenium cluster compounds [Re₆S₈(CN)₂(py)₄]·H₂O (1), [Re₆S₈(CN)₂(4-Mepy)₄] (2), [Re₆S₈(CN)₂(4-Mepy)₄]·4-Mepy (3) (py = pyridine, 4-Mepy = 4-methylpyridine) are determined by X-ray crystallography. Crystal data are: C2/m space group, a = 14.813(1) Å, b = 14.772(1) Å, c = 9.2122(6) Å, β = 119.085(2)°, V = 1761.7(2) ų, d _x = 3.318 g/cm³, R = 0.0585 (1); I4₁/amd space group, a = 16.0018(3) Å, c = 14.7186(5) Å, V = 3768.81(16) ų, d _x = 3.169 g/cm³, R = 0.0489 (2); P2₁/c space group, a = 9.0452(4) Å, b = 15.8065(7) Å, c = 15.2951(6) Å, β = 103.700(2)°, V = 2124.57(16) ų, d _x = 2.957 g/cm³, R = 0.0245 (3). Molecular cluster complexes interact via π-π stacking affording 3D frameworks in 1 and 2 and chains in 3.     

Structural investigation of [Au(en)<Subscript>2</Subscript>]Cl(ReO<Subscript>4</Subscript>)<Subscript>2</Subscript> and [Au(en)<Subscript>2</Subscript>](ReO<Subscript>4</Subscript>)<Subscript>3</Subscript> complexes

Novel complex salts [Au(en)₂]Cl(ReO₄)₂ (I) and [Au(en)₂](ReO₄)₃ (II), en = ethylenediamine, are obtained. Their crystal structures are determined by single crystal X-ray diffraction. Complex I crystallizes in the triclinic crystal system: a = 6.2172(7) Å, b = 7.1644(8) Å, c = 8.8829(8) Å, α = 96.605(4)°, β = 110.000(4)°, γ = 97.802(4)°, P-1 space group, Z = 1, d _x = 3.905 g/cm³; complex II crystallizes in the monoclinic crystal system: a = 15.244(2) Å, b = 7.6809(8) Å, c = 9.3476(12) Å, β = 127.004(3)°, C2 space group, Z = 4, d _x = 4.057 g/cm³.     

Three- and four-coordinated silver(I) ions in the coordination polymers [Ag(Me<Subscript>4</Subscript>Pyz)<Subscript>2</Subscript>]PF<Subscript>6</Subscript> and [Ag(2,3-Et<Subscript>2</Subscript>Pyz)<Subscript>2</Subscript>]PF<Subscript>6</Subscript>

The coordination polymers [AgPF₆(Me₄Pyz)₂] (I) and [AgPF₆(2,3-Et₂Pyz)₂] (II) were synthesized, and their structures were determined. Crystals of I are monoclinic, space group C2/c, a = 10.213(2) Å, b = 16.267(3) Å, c = 12.663(3) Å, β = 92.90(3)°, V = 2102.1(7) ų, ρ_calcd = 1.660 g/cm³, Z = 4. The structure of I is built of polymeric zigzag [Ag(C₈H₁₂N₂)] _∞ ⁺ chains and octahedral [PF₆] anions. The coordination polyhedron of the Ag⁺ ion is a flat triangle. Crystals of II are tetragonal, space group P \(\bar 4\)2(1)/c,a = b = 10.641(1) Å, c = 18.942(1) Å, V = 2144.6(2) ų, ρ_calcd = 1.627 g/cm³, Z = 4. In the structure of II, 2D cationic layers of fused square rings exist; the rings consist of four Ag⁺ cations linked by four bridging ligands of diethylpyrazine Et₂Pyz. The coordination polyhedron of the Ag⁺ ion is an irregular four-vertex polyhedron.     

Crystal structures of polyphosphates MCs<Subscript>5</Subscript>(PO<Subscript>3</Subscript>)<Subscript>8</Subscript> (M = Pr,Eu, and Gd)

Crystals of double polyphosphates EuCs₅(PO₃)₈ (I) and GdCs₅(PO₃)₈ (II) have been studied by X-ray diffraction. The isostructural crystals of I and II are monoclinic, space group C2. Only unit cell parameters have been determined for the crystals of double Pr and Cs polyphosphate (III). This crystal is isostructural with earlier studied La₃Cs₁₅P₂₄O₇₂ · 6H₂O (IV). The crystals of compounds III and IV are triclinic, space group P1, Z = 1; a = 11.987(2) and 12.178(5) Å, b = 14.754(8) and 14.740(8) Å, c = 14.692(8) and 14.847(9) Å, α = 60.15(4)° and 60.87(5)°, β = 67.04(4)° and 66.35(4)°, γ = 78.76(3)° and 77.54(4)°, respectively. In compounds I and II, the polyphosphate anions exist as infinite chains. The M^IIIO₈ polyhedra are isolated from each other but share edges and faces with the CsO _n polyhedra.     

Binuclear bismuth halide complexes (<Emphasis Type="Italic">N</Emphasis>-Me(2,2'-BipyH))<Subscript>2</Subscript>[Bi<Subscript>2</Subscript>X<Subscript>10</Subscript>] (X = Cl,Br): Syntheses,crystal structures,and optical properties

Binuclear halide complexes (N-Me(2,2'-BipyH)₂[Bi₂X₁₀] (X = Cl (I), Br (II); 2,2'-Bipy = 2,2'-bipyridine) are synthesized by the reaction of solutions of [BiX₆]^3– and (N-Me(2,2'-BipyH)(NO₃)₂ in 2 M HX. The structure of [Bi₂X₁₀]^4– anions consists of octahedral fragments {BiX₆} linked by two μ₂-bridging halide ligands. The structures of the compounds are determined by X-ray diffraction analysis (CIF files CCDC 1455987 (I) and 1455988 (II)). The forbidden gap width E _g is determined for complex II from the diffuse reflectance spectrum.     

Syntheses and crystal structures of [Bi(DMSO)<Subscript>8</Subscript>][Fe(NCS)<Subscript>6</Subscript>] and [Al(DMSO)<Subscript>6</Subscript>][Al(NCS)<Subscript>6</Subscript>]

New complexes of composition [Bi(DMSO)₈][Fe(NCS)₆] (1) and [Al(DMSO)₆][Al(NCS)₆] (2) have been prepared, and an octahedral hexarodanoaluminate anion has been structurally characterized for the first time. Crystals of compound 1 are triclinic, space group \(P\bar 1\), a = 11.2368(4) Å, b = 11.4063(4) Å, c = 21.0711(9) Å, α = 92.9520(10)°, β = 99.9430(10)°, γ = 111.9290(10)°, V = 2447.69(16) ų, Z = 2, ρ_calc = 1.680 g/cm³, R ₁ = 0.0564; crystals of compound 2 are cubic, space group \(Pa\bar 3\), a = 15.8201(4) Å, V = 3959.39(17) ų, Z = 4, ρ_calc = 1.462 g/cm³, R ₁ = 0.0475. The bismuth coordination polyhedron BiO₈ in compound 1 is a distorted square antiprism with broken square faces (Bi-O, 2.368-2.582 Å). In the structure of 2, the cation disordered in a complex manner has an octahedral configuration (Al-O, 1.888(11)-1.912(11) Å).     

Synthesis,structure, physicochemical properties,and solid-phase thermolysis of Co<Subscript>2</Subscript>Sm(Piv)<Subscript>7</Subscript>(2,4-Lut)<Subscript>2</Subscript>

Heterometallic pivalate Co₂Sm(Piv)₇(2,4-Lut)₂ (1) was prepared for the first time and structurally characterized at 293 and 160 K. Antiferromagnetic exchange interactions are dominant in complex 1. This compound experiences a first-order phase transition within 210–260 K. A set of thermodynamic functions was obtained for this complex (C _p , H _T ⁰ - H ₁₈₀ ⁰ , and S _T ⁰ ), and parameters were determined for solid-phase thermolysis where samarium cobaltate SmCoO₃ is the only product.     

Syntheses and crystal structures of (2.2.2-cryptand)potassium chloride and (2.2.2-cryptand)ammonium bromide<Subscript>(0.75)</Subscript>chloride<Subscript>(0.25)</Subscript> hydrates

Two new complexes were synthesized, namely, 7: 2 (2.2.2-cryptand)potassium chloride and (2.2.2-cryptand)ammonium bromide_(0.75)chloride_(0.25) hydrates: [M(Crypt-222)]⁺ · Hal^? · 3.5H₂O, where M = K, Hal = Cl (I) and M = NH₄, Hal = Br_0.75Cl_0.25 (II). The structures of two isomorphous crystals were studied by X-ray diffraction analysis. Trigonal (space group P \(\bar 3\), Z = 2) structures I (a = 11.763 Å, c = 11.262 Å) and II (a = 11.945 Å, c = 11.337 Å) were solved by direct methods and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.057 (I) and 0.065 (II) for all 2626 (I) and 1654 (II) independent measured reflections (CAD-4 automated diffractometer, λMoK _α). In structures I and II, the host-guest [M(Crypt-222)]⁺ complex cation lies on the threefold crystallographic axis and has the approximate D ₃ symmetry. In complex I, the coordination polyhedron of the K⁺ cation (CN = 8) is a bicapped trigonal prism somewhat distorted toward an antiprism. Complexes I and II contain H-bonded disordered cubes of the water molecules and the Cl^? or Br^? anions.     

Crystal Structure of Tl<Subscript>2</Subscript>[NbCl<Subscript>6</Subscript>] and Tl<Subscript>2</Subscript>[NbBr<Subscript>6</Subscript>]

Single crystals of Tl₂[NbCl₆] (1) and Tl₂ [NbBr₆] (2) are obtained as black needles on heating TlCl, Nb, S₂Cl₂ (1) and Tl, Nb, and Br₂ at 400°C (2). Tl₂NbBr₆ also forms in the reaction of TlBr, Nb, Br₂, and S at 500°C. Both compounds crystallize in the K₂[PtCl₆] structure type to form non-distorted octahedral [NbХ₆]^2– anions (Nb–Cl 2.397(4) Å and Nb–Br 2.516(2) Å). The magnetic properties of Tl₂[NbBr₆] in a range 5-300 K indicate an antiferromagnetic interaction between Nb⁴⁺ ion spins (d¹, S = 1/2). On cooling, the compound becomes a noncollinear ferromagnet with T_c = 23 K.     

Synthesis,structural, spectral,thermal and comparative biological activity studies of [V<Subscript>2</Subscript>O<Subscript>2</Subscript>(SO<Subscript>4</Subscript>)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>]

The hydrothermal reaction of a mixture of V₂O₅, VCl₃, 2,5-pyridinedicarboxylic acid and diluted H₂SO₄ for 68 h at 180°C gives a blue colored solution which yields prismatic blue crystals of IV ₂ ^IV O₂(SO₄)₂(H₂O)₆] (1) in 32% yield (based on V). Complex 1 was investigated by means of elemental analysis (C, H and S), TGA, FT-IR, manganometric titration, Single Crystal X-ray Diffraction Methods and also comparative antimicrobial activities. Crystal data for the compound: monoclinic space group P2₁/c and unit cell parameters are a = 7.3850(12) Å, b = 7.3990(7) Å, c = 12.229(2) Å, β = 108.976(12)° and Z = 2. Although structure of 1 as a natural mineral has been previously determined, this work covers new preparation method and full characterization of 1 along with comparison of antibacterial activity between 1 and the commercial vanadium(IV) oxide sulfate hydrate compounds, VOSO₄ · xH₂O (Riedel-de Haën and Alfa Aesar brand names). 1 was evaluated for the antimicrobial activity against gram-positive, gram-negative bacteria, yeasts and mould compared with the commercial VOSO₄ · xH₂O compounds. 1 showed weak activity against bacteria Bacillus cereus, Nocardia asteroides and yeast Candida albicans. A good antimicrobial activity was recorded against Cirtobacter freundii (15 mm). There are only a few reproducible well-defined vanadium(IV) starting materials to use for exploring the synthesis of new materials. VCl₄, VO(acac)₂, VOSO₄ · xH₂O and [V(IV)OSO₄(H₂O)₄] · SO₄ · [H₂N(C₂H₄)₂NH₂] are common starting materials for such applications. In addition to these compounds, 1 can be used as an oxovanadium precursor.     

A novel metal chalcogenide: HgCd<Subscript>4</Subscript>S<Subscript>5</Subscript>

A novel metal chalcogenide HgCd₄S₅ (1) was synthesized from solid-state reactions and structurally characterized. Compound 1 crystallizes in the space group C222₁ of the orthorhombic system with four formula units in a cell: a = 12.5661(5) Å, b = 7.2551(5) Å, c = 10.7520(7) Å, V = 980.2(1) ų, Cd₄HgS₅, M _r = 810.49, D _c = 5.492 g/cm³, S = 1.010, μ(MoK _α) = 25.128 mm^?1, F(000) = 1408, R = 0.0611 and wR = 0.1495. Compound 1 is characterized by a 3-D cadmium sulfide framework structure with the infinite mercury sulfide chains located in the cavities.     

Crystal structure and properties of [M(NH<Subscript>3</Subscript>)<Subscript>5</Subscript>Cl](NO<Subscript>3</Subscript>)<Subscript>2</Subscript>, (M = Ir,Rh, Ru)

The crystal structures of compounds from the series [M(NH₃)₅Cl](NO₃)₂, (M = Ir, Rh, Ru) were described. The compounds crystallized in the tetragonal crystal system, space group I4, Z = 2. Crystal data for [Ir(NH₃)₅Cl](NO₃)₂ (I): a = 7.6061(1) Å, b = 7.6061(1) Å, c = 10.4039(2) Å, V = 601.894(16) ų, ρ_calc = 2.410 g/cm³, R = 0.0087; [Rh(NH₃)₅Cl](NO₃)₂ (II): a = 7.5858(5) Å, b = 7.5858(5) Å, c = 10.41357(7) Å, V = 599.24(7) ų, ρ_calc = 1.926 g/cm³, R = 0.0255; [Ru(NH₃)₅Cl](NO₃)₂ (III): a = 7.5811(6) Å, b = 7.5811(6) Å, c = 10.5352(14) Å, V = 605.49(11) ų, ρ_calc = 1.896 g/cm³, R = 0.0266. The compounds were defined by IR spectroscopy and XRPA and thermal analyses.     

Synthesis and crystal structure of two complexes [Cu<Subscript>2</Subscript>(NiL)<Subscript>2</Subscript>Cl<Subscript>4</Subscript>] and [Cd<Subscript>2</Subscript>(CuL)<Subscript>2</Subscript>Cl<Subscript>4</Subscript>]

Macrocyclic and supermolecular complexes [Cu₂(NiL)₂Cl₄] (I) and [Cd₂(CuL)₂Cl₄] (II) (H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-diene) have been synthesized and structurally determined by X-ray diffraction and IR spectrum. Complex I crystallizes in the monoclinic system with P2₁/n group, a = 10.9019(15), b = 14.3589(19), c = 12.4748(17) 0A, β = 108.645(2)°, Z = 4. Complex II crystallizes in the monoclinic system with P2₁/n group, a = 10.9784(16), b = 14.580(2), c = 12.8904(18) Å, β = 109.339(2)°, Z = 4.     

Crystal Structures of New Chalcogenide- Containing Yttrium Orthosilicates Y<Subscript>2</Subscript>SiO<Subscript>4</Subscript>Q (Q = S,Se)

Compounds Y₂SiO₄Q (Q = S, Se) are obtained by the interaction of oxides and elemental substances in cesium chloride flux. The structures of these compounds are determined by the single crystal XRD analysis. These compounds isostructural and crystallize in the space group Pbcm with the following parameters: Y₂SiO₄S (I) a = 6.0462(8) Å, b = 6.8976(9) Å, c = 10.6558(13) Å, V = 444.39(10) ų; Y₂SiO₄Se (II) a = 5.9935(7) Å, b = 6.9216(8) Å, c = 10.7688(12) Å, V = 446.74(9) ų. The measured fluxing points are 1650±15 °С for I and 1850±15 °С for II.     

<Emphasis Type="Italic">cis</Emphasis>-Dioxomolybdenum(VI) complexes of sterically encumbered phenol-based tetradentate N<Subscript>2</Subscript>O<Subscript>2</Subscript> ligands: Structural,spectroscopic, and electrochemical studies

Two cis-dioxomolybdenum(VI) complexes [MoO₂L] (L: L ¹, 2 and L: L ², 3) in a phenol-based sterically encumbered N₂O₂ ligand environment have been synthesized, and their crystallographic characterizations are reported. The orange crystals of 2 are monoclinic, space group P2₁/a with unit cell dimensions as a=16.2407(17) Å, b=7.2857(8) Å, c=18.400(2) Å, β=98.002(9)°, Z=4, and d _cal=1.486 g cm^?3. The light orange crystals of 3, however, are orthorhombic, space group, Pbcn, with unit cell dimensions a=8.3110(12) Å, b=12.637(3) Å, c=34.673(5) Å, Z=4, and d _cal=1.187 g cm^?3. The structures were refined by a full-matrix least-squares procedure on F ² to a final R=0.046 (0.055 for 3) using 4944 (3677) all independent data. In both the cases, the Mo atom exists in a distorted octahedral geometry defined by a N₂O₄ donor set, which features a cis-Mo(–O)₂ and a trans-Mo(OPh)₂ arrangement. Compound 2 undergoes a quasireversible one-electron reduction at ?1.3 V vs Ag/AgCl reference due to Mo^VIO₂/Mo^VO₂ electron transfer and thus providing a rare example of steric solution to the comproportionation–dimerization problem encountered frequently in the development of valid biomimetic models for the active sites of oxomolybdenum enzymes.     

Study of the monocarbonate complex of pentavalent neptunium (NH<Subscript>4</Subscript>)[NpO<Subscript>2</Subscript>(CO<Subscript>3</Subscript>)]

The single crystals of the Np(V) complex (NH₄)[NpO₂(CO₃)] (I) were synthesized and studied by X-ray diffraction. At 100 K, the crystals are hexagonal, space group P6₃ μmc, a = 5.0734(1) Å, c = 10.9191(2) Å, V= 243.399(11) ų, Z = 2, ρ(calcd) = 4.735 g/cm³. The absorption spectra of a crystal of I in the visible and infrared ranges were measured.     

Crystal Structure of [UO<Subscript>2</Subscript>SO<Subscript>4</Subscript>{(CH<Subscript>3</Subscript>)HNCONH(CH<Subscript>3</Subscript>)}<Subscript>2</Subscript>]

The single crystals of [UO₂SO₄{(CH₃)HNCONH(CH₃)}₂] (I) were synthesized and studied by X-ray diffraction. The crystals are monoclinic, a = 6.847(1) Å, b = 14.259(3) Å, c = 14.297(3) Å, β = 93.451(4)°, space group P2₁/n, Z = 4. The main structural units of crystals I are ribbons whose composition coincides with the composition of the compound. The crystal chemical formula of the complex is AT³M ₂ ¹ (A = UO ₂ ²⁺ ).     

Structure of a new chelate complex MO<Subscript>2</Subscript>O<Subscript>3</Subscript>(dpm)<Subscript>4</Subscript>

A new Mo₂O₃(dpm)₄ compound (I) is synthesized by the interaction of Mo(CO)₆ with 2,2,6,6-tetramethylheptanedione-3,5 (dpm). The structure of complex I determined by the XRD method is as follows: triclinic crystal system, space group P–1, a = 10.1780(7) Å, b = 10.1817(6) Å, c = 13.3255(9) Å, α = 110.562(2)°, β = 102.233(2)°, γ = 93.9041(19)°, V = 1248.17(14) ų. The compound is characterized by IR spectroscopy, mass-spectrometry and thermogravimetric analysis (TGA).