Synthesis and crystal structure of [(C<Subscript>7</Subscript>H<Subscript>10</Subscript>N)<Subscript>2</Subscript>]<Superscript>2+</Superscript> [Sb<Subscript>2</Subscript>Cl<Subscript>8</Subscript>]<Superscript>2−1</Superscript>

The reaction of 2,6-dimethylpyridine with SbCl₃ and HCl affords the title compound, the structure of which is ascertained by X-ray diffraction. The unit cell consists of one bridged Sb₂Cl₈²⁻ anion and two 2,6-dimethylpyridinium cations. The trivalent antimony ion is bonded not only directly to chlorine anions, but also is coordinated with chlorine anions by secondary bonds. In the crystal, there exists infinite coordinated chains of [Sb₂Cl₈] _n ²ⁿ⁻ anions running along the a axis, which link 2,6-dimethylpyridinium cations by N-H…Cl hydrogen bonds.     

Molecular structure of [(<Superscript>t</Superscript>Bu)<Subscript>2</Subscript>Al(μ-OC<Subscript>6</Subscript>H<Subscript>4</Subscript>-2-Me)]<Subscript>2</Subscript>

The molecular structure of [(^tBu)₂Al(-OC₆H₅-2-Me)]₂ has been determined. Both the ortho-tolyl methyl groups are oriented towards Al(2). The intramolecular steric interaction between the ortho-methyl groups and the tert-butyl ligands results in the geometry about the bridging oxygen being significantly distorted while the geometries about the aluminum centers show a distortion from tetrahedral that is less than the sterically less hindered [(^tBu)₂Al(-OPh)]₂. Crystal data: group C2/c, a = 13.733(3) Å, b = 15.135(3) Å, c = 15.420(3) Å, = 104.24(3), V = 3106(1) ų, Z = 4, R = 0. 0612, wR₂ = 0.1787.     

Optical properties and refractive indices of Gd<Subscript>3</Subscript>Al<Subscript>2</Subscript>Ga<Subscript>3</Subscript>O<Subscript>12</Subscript>:Се<Superscript>3+</Superscript> crystals

Crystals of cerium-doped gadolinium–gallium–aluminum garnet have been grown by the Czochralski method. The transmission and reflection spectra of these crystals in the wavelength range of 250–800 nm have been obtained by optical spectroscopy. Refractive indices are calculated based on the measured Brewster angles, the experimental results are approximated using the Cauchy equation, and a dispersion dependence is obtained.     

Crystal structure of Sr(AsUO<Superscript>6</Superscript>)<Subscript>2</Subscript> · 8H<Subscript>2</Subscript>O

The crystal structure of the compound Sr(AsUO₆)₂ · 8H₂O is determined by X-ray diffraction analysis (monoclinic system, sp. gr. Pc, unit-cell parameters a = 7.154(1) Å, b = 7.101(1) Å, c = 18.901(7) Å, β = 92.67(2)°, Z = 2). The structure is built by (001)-parallel [AsUO₆]^? layers formed by flattened square UO₆ bipyramids and AsO₄ tetrahedra. The neighboring layers are connected via SrO₈ square antiprisms. The cavities of the polyhedral framework thus formed are occupied by H₂O molecules. The displacements of the anion complexes by a half-translation with respect to one another along only one lattice period is a characteristic feature of this polymorphous modification of the uran-mica group.     

Synthesis and structure of [(NH<Subscript>2</Subscript>)<Subscript>2</Subscript>CSSC(NH<Subscript>2</Subscript>)<Subscript>2</Subscript>]<Subscript>2</Subscript>[OsBr<Subscript>6</Subscript>]Br<Subscript>2</Subscript> · 3H<Subscript>2</Subscript>O

The complex [(NH₂)₂CSSC(NH₂)₂]₂[OsBr₆]Br₂ · 3H₂O is synthesized by the reaction of K₂OsBr₆ with thiocarbamide in concentrated HBr and characterized using electronic absorption and IR absorption spectroscopy. Its crystal structure is determined by X-ray diffraction. The crystals are orthorhombic, a = 11.730(2) Å, b = 14.052(3) Å, c = 16.994(3) Å, space group Cmcm, and Z = 4. The [OsBr₆]^2? anionic complex has an octahedral structure. The Os-Br distances fall in the range 2.483–2.490 Å. The α,α′-dithiobisformamidinium cation is a product of the oxidation of thiocarbamide. The S-S and C-S distances are 2.016 and 1.784 Å, respectively. The H₂O molecules, Br^?ions, and NH₂ groups of the cation are linked by hydrogen bonds.     

Crystal structure and properties of K<Subscript>2</Subscript>[OsO<Subscript>2</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>2</Subscript>] · 2H<Subscript>2</Subscript>O

The synthesis and X-ray diffraction study of the compound K₂[OsO₂(C₂O₄)₂] · 2H₂O are performed. The compound crystallizes in the triclinic crystal system, space group P \(\bar 1\), a = 6.545(1) Å, b = 6.835(2) Å, c = 7.595(2) Å, α = 85.76(2)°, β = 65.33(2)°, γ = 71.14(2)°, and Z = 1. The osmium atom is located at the center of symmetry and has a distorted octahedral coordination formed by oxygen atoms: two oxygen atoms of the osmyl group occupy the apical positions [Os-O, 1.730(2) Å], and four oxygen atoms of the oxalate ions lie in the equatorial plane. The K⁺ cation is surrounded by ten oxygen atoms located at different K-O distances in the range from 2.787(2) to 3.158(2) Å. The assignment of the absorption bands in the IR spectrum of K₂[OsO₂(C₂O₄)₂] · 2H₂O is performed. The electronic absorption spectra of the compound are recorded in different solvents, and the thermal behavior in air is studied.     

Aquanitrilotris(methylenephosphonato)dirubidium [Rb<Subscript>2</Subscript>(H<Subscript>2</Subscript>O){μ<Superscript>12</Superscript>-NH(CH<Subscript>2</Subscript>PO<Subscript>3</Subscript>H)<Subscript>3</Subscript>}]: Synthesis and structure

Aquanitrilotris(methylenephosphonato)dirubidium is a 3D coordination polymer with a layer structure. Space group \(P\bar 1\), Z = 2; a = 8.0380(3) Å, b = 9.0522(4) Å, and c = 10.7837(4) Å; α = 113.252(4)°, β = 105.391(3)°, and γ = 96.182(3)°. Rb atoms populate two symmetrically inequivalent positions with c.n. = 8 and 10; significant difference in O–Rb–O angles in the coordination polyhedra is indicative of the ionic type of Rb–O bonds. In the crystal packing, molecules are connected by not only coordination bonds but hydrogen bonds as well.     

Synthesis and X-ray diffraction study of [UO<Subscript>2</Subscript>(NO<Subscript>3</Subscript>)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>] · 2C<Subscript>12</Subscript>H<Subscript>18</Subscript>O

The compound [UO₂(NO₃)₂(H₂O)₂] · 2C₁₂H₁₈O was synthesized and studied by IR spectroscopy and X-ray diffraction. The structure consists of the neutral island groups [UO₂(NO₃)₂(H₂O)₂], which belong to the crystal-chemical group AB ⁰¹ ₂ M ¹ ₂ (A = UO₂ ²⁺, B ⁰¹ = NO₃⁻, M ¹ = H₂O) of uranyl complexes, and 1-adamantyl methyl ketone molecules. The characteristic features of the association of the complexes [UO₂(NO₃)₂(H₂O)₂] and 1-adamantyl methyl ketone molecules in the crystal structure via hydrogen bonds are considered with the use of Voronoi-Dirichlet polyhedra.     

Base-Stabilized Monomeric Stibinoalane dmap–Al(Et<Subscript>2</Subscript>)Sb(<Superscript>t</Superscript>Bu)<Subscript>2</Subscript>

Abstract  

The six-membered heterocycle [Me₂AlSb(t-Bu)₂]₃ was reacted with the strong Lewis-base 4-dimethylaminopyridine (dmap), yielding the first completely alkyl-substituted monomeric complex dmap–Al(Me₂)Sb(t-Bu)₂ 1. 1 was characterized by NMR spectroscopy and single crystal X-ray diffraction. 1 is monoclinic, space group P2 ₁ /n with a = 9.9004(2) ?, b = 16.8166(3) ?, c = 13.8400(3) ?, β = 100.746(1)° and Z = 4.     

Solvothermal Syntheses and Crystal Structures of Two Thiostannates(IV) [M(tepa)]<Subscript>2</Subscript>(<Emphasis Type="Italic">μ</Emphasis>-Sn<Subscript>2</Subscript>S<Subscript>6</Subscript>) (M = Fe<Superscript>2+</Superscript> and Co<Superscript>2+</Superscript>)

Abstract  

Two new thiostannates [M(tepa)]₂(μ-Sn₂S₆) (tepa = tetraethylenepentamine, M = Fe²⁺ 1 and Co²⁺ 2) were prepared by solvothermal method. Compounds 1 and 2 are isostructural. Both the compounds crystallize in the tetragonal system, space group I41/a (no. 88) with the crystal parameters of 1: a = 25.683(2) ?, b = 25.683(2) ?, c = 9.9860(9) ?, V = 6,586.7(11) ?³, Z = 8, and 2: a = 25.742(3) ?, b = 25.742(3) ?, c = 9.8977(12) ?, V = 6,558.5(14) ?³, Z = 8. The Sn₂S₆ ⁴⁻ anion acts as a bidentate bridging ligand connecting two transition metal complex cations by trans terminal S atoms to form neutral centrosymmetric [M(tepa)]₂(μ-Sn₂S₆) moieties.     

Crystal and molecular structure of phenanthrolinium peroxodisulfate dihydrate (C<Subscript>12</Subscript>H<Subscript>9</Subscript>N<Subscript>2</Subscript>)<Subscript>2</Subscript>S<Subscript>2</Subscript>O<Subscript>8</Subscript> · 2H<Subscript>2</Subscript>O

The crystal structure of (HPhen)₂S₂O₈ · 2H₂O is studied using X-ray diffraction. The crystals are monoclinic, a = 23.716(5) Å, b = 10.220(2) Å, c = 13.103(3) Å, β = 128.03(2)°, V = 2501.6(9) ų, Z = 4, space group C2/c, and R = 0.0745 for 1579 reflections with I > 2σ(I). The crystal is built of S₂O ₈ ^2? centrosymmetric anions, HPhen ⁺ cations, and molecules of crystallization water. Hydrogen bonds link the structural units into chains. Within a chain, stacking interactions are observed between the phenanthroline rings (the interplanar spacing between the rings is 3.8 Å, and the dihedral angle between their planes is 8°). The data of IR spectroscopy confirm the formation of the N(Phen)-H bond.     

Synthesis and crystal structure of Na<Subscript>3</Subscript>(H<Subscript>3</Subscript>O)[UO<Subscript>2</Subscript>(SeO<Subscript>3</Subscript>)<Subscript>2</Subscript>]<Subscript>2</Subscript>· H<Subscript>2</Subscript>O

Single crystals of the compound Na₃(H₃O)[UO₂(SeO₃)₂]₂ · H₂O (I) have been synthesized, and their structure has been investigated using X-ray diffraction. Compound I crystallizes in the triclinic system with the unit cell parameters a = 9.543(6)Å, b = 9.602(7)Å, c = 11.742(8)Å, α = 66.693(16)°, β = 84.10(2)°, γ = 63.686(14)°, space group P \(\bar 1\), Z = 2, and R = 0.0734. The uranium-containing structural units of the crystals are [UO₂(SeO₃)₂]^2? chains, which belong to the crystal-chemical group AB ² B ¹¹ (A = UO ₂ ²⁺ , B ² = SeO ₃ ^2? , B ¹¹ = SeO ₃ ^2? ) of the uranyl complexes. The structures of the compounds containing the [UO₂(SeO₃)₂]^2? anionic complexes are compared.     

Crystal structure of new micalike titanosilicate—bussenite,Na<Subscript>2</Subscript>Ba<Subscript>2</Subscript>Fe<Superscript>2+</Superscript>[TiSi<Subscript>2</Subscript>O<Subscript>7</Subscript>][CO<Subscript>3</Subscript>]O(OH)(H<Subscript>2</Subscript>O)F

The crystal structure of mineral bussenite, Na₂Ba₂Fe[TiSi₂O₇][CO₃]O(OH)(H₂O)F, found in the Khibiny massif (the Kola Peninsula) has been determined. The parameters of the triclinic unit-cell are a = 5.399(3) Å, b = 7.016(9) Å, c = 16.254(14) Å, α = 102.44(8)°, β = 93.18(6)°, γ = 90.10(7)°, sp. gr. \(P\bar 1\), R = 0.054 for 1418 reflections with |F| > 2.5σ(F). The mineral studied belongs to the family of layered titanosilicates, in which, unlike the sulfate-and phosphate-containing representatives of this family, the interlayer spaces are filled with carbonate groups.     

X-ray diffraction study of Rb<Subscript>2</Subscript>[(UO<Subscript>2</Subscript>)<Subscript>2</Subscript>(CrO<Subscript>4</Subscript>)<Subscript>3</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

The compound Rb₂[(UO₂)₂(CrO₄)₃(H₂O)₂] · 4H₂O was studied by X-ray diffraction. The crystals are monoclinic, a = 10.695(2) Å, b = 14.684(3) Å, c = 14.125(3) Å, β = 108.396(4)°, sp. gr. P2₁/c, Z = 4, V = 2104.9(7) ų, and R = 0.0491. The main structural units are layers consisting of [(UO₂)₂(CrO₄)₃(H₂O)₂]^2? anions belonging to the crystal-chemical group A ₂ T ₂ ³ B ²M ₂ ¹ (A = UL ₂ ²⁺ , T ³ and B ² are CrO ₄ ^2? , and M ¹ is H₂O) of uranyl complexes. The uranium-containing layered groups are held together by electrostatic interactions with rubidium cations, as well as by hydrogen bonds with the participation of inner- and outer-sphere water molecules.     

Synthesis and crystal structure of [UO<Subscript>2</Subscript>CrO<Subscript>4</Subscript>(C<Subscript>5</Subscript>NH<Subscript>5</Subscript>COO)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)]·2H<Subscript>2</Subscript>O

Crystals of UO₂CrO₄(C₅NH₅COO)₂(H₂O)] · 2H₂O are synthesized and their structure is studied by X-ray diffraction. The compound crystallizes in the triclinic crystal system. The unit cell parameters are as follows: a = 7.0834(10) Å, b = 10.6358(14) Å, c = 12.9539(17) Å, α = 75.096(2)°, β = 74.490(2)°, and γ = 80.657(2)°; V = 904.1(2) ų, space group P \(\bar 1\), Z = 2, and R = 0.026. The structure is built of [UO₂CrO₄(C₅NH₅COO)₂(H₂O)]₂ centrosymmetric dimers, which are linked into a framework by a system of hydrogen bonds involving inner-sphere and outer-sphere water molecules. The coordination number of the U(VI) atom is seven, and the coordination polyhedron is a pentagonal bipyramid with the oxygen atoms of the uranyl group, two chromate groups, two molecules of isonicotinic acid, and a water molecule at the vertices. The crystal chemical formula of the [UO₂CrO₄(C₅NH₅COO)₂(H₂O)]₂ dimer is represented as AB ² M ₃ ¹ , where AB ² M ₃ ¹ , where A = UO ₂ ²⁺ , B ² = CrO ₄ ^2? , and M ¹ = = C₅NH₄COOH and H₂O.     

Optical and nonlinear laser properties of the χ<Superscript>(3)</Superscript>-active monoclinic α-KY(WO<Subscript>4</Subscript>)<Subscript>2</Subscript> crystals

Monoclinic α-KRE(WO₄)₂ crystals are grown. Their structure is described in two crystallographic settings. The principal refractive indices are determined and the coefficients and characteristic wavelengths are used for calculating refractive indices by the Selmeyer formulas. The data on the anisotropic parametric Raman generation in these crystals under the picosecond pumping are discussed.     

Triosmium and triruthenium clusters containing morpholine ligand: X-ray structure of Os<Subscript>3</Subscript>(CO)<Subscript>10</Subscript>(μ-η<Superscript>2</Superscript>-NC<Subscript>4</Subscript>H<Subscript>6</Subscript>O)(μ-H)

Treatment of the labile cluster Os₃(CO)₁₀(CH₃CN)₂ with morpholine in benzene at 60^°C afforded Os₃(CO)₁₀(μ-η²-NC₄H₆O)(μ-H) (1). Decarbonylation of 1 at 128^°C gave Os₃(CO)₉(μ₃-η²-NC₄H₆O)(μ-H) (2), which reacts with PPh₃ at ambient temperature to give an addition product Os₃(CO)₉(μ-η²-NC₄H₆O)(PPh₃)(μ-H) (3). Compound 1 reacted with PPh₃ at 98^°C to give the substitution product 4 which is an isomer of 3. The reaction of Ru₃(CO)₁₂ with morpholine in the presence of Me₃NO in refluxing benzene at 80^°C afforded Ru₃(CO)₉(μ₃-η²-NC₄H₆O)(μ-H) (5). Compounds 1– 5 have been characterized by elemental analysis, infrared, ¹H NMR, and mass spectroscopic data. The molecular structure of 1 has been determined by single crystal X-ray diffraction analysis. Compound 1 crystallizes in the monoclinic space group P2/c with a = 29.598(8) Å, b = 9.202(2) Å, c = 14.496(4) Å, β = 93.19(3)^°, Z = 8, and V = 3942(2) ų. Compound 1 consists of an isosceles triangle of osmium atoms with one elongated Os–Os edge, which is bridged by the hydride and the morpholine ligand.     

Crystal structure and properties of [OsO<Subscript>2</Subscript>(NH<Subscript>3</Subscript>)<Subscript>4</Subscript>]SO<Subscript>4</Subscript> · H<Subscript>2</Subscript>O

The structure of a single crystal of tetraammindioxoosmium(VI) sulfate [OsO₂(NH₃)₄]SO₄ · H₂O, which is synthesized by the reaction of K₂[OsO₂(OH)₄] with (NH₄)₂SO₄ in an aqueous solution, is investigated using X-ray diffraction analysis. The compound crystallizes in the monoclinic crystal system, space group P2₁/c, a = 13.102(2) Å, b = 6.158(3) Å, c = 11.866(2) Å, β = 98.13(2)°, and Z = 4. The [OsO₂(NH₃)₄]SO₄ · H₂O compound has an island structure. Two crystallographically independent osmium atoms are situated at the centers of symmetry, and their octahedral coordination includes two oxygen atoms and four nitrogen atoms of the ammonia molecules. In both octahedra, the osmyl group is linear. The Os-O distances in the octahedra are identical within the standard deviations [Os(1)-O, 1.762(2) Å; Os(2)-O, 1.769(2) Å]. The Os-N bond lengths vary from 2.082(3) to 2.101(3) Å. The cationic complexes, SO₄ groups, and water molecules are linked via the system of hydrogen bonds. The assignment of the absorption bands in the IR spectrum of the compound synthesized is performed, and its thermal behavior in air is studied.     

Hydrogen Atoms Location in Os<Subscript>3</Subscript>(μ-H)(CO)<Subscript>9</Subscript>(μ<Subscript>3</Subscript>, η<Superscript>2</Superscript>-C<Subscript>2</Subscript>H) from Accurate X-Ray Data at 100 K

Abstract  

The structure of the complex Os₃(μ-H)(CO)₉(μ₃, η²-C₂H) has been determined using X-ray data collected at low temperature (100 K); all hydrogen atoms have been located. The asymmetric unit is formed by two molecules joined through hydrogen bonds involving the hydrogen atoms of C₂H moiety and the oxygen atoms of carbonyl groups. The complex crystallizes in the monoclinic space group P2₁/c with a = 12.94040(2), b = 15.4705(2), c = 16.0164(2) ?, β = 106.0860(10)°, and V = 3,080.85(7) ?³, Z = 8. A molecule is formed by a triangular Os₃ cluster, with metal atoms bearing terminal CO groups. The acetylenic residual is formally π-bonded to two Os atoms in a perpendicular mode and σ-linked to the third Os atom. A bridging hydride atom completes the coordination.     

Synthesis and Crystal Structures of Three Pyrazine-2-carboxylate Containing Isostructural Complexes: M(2-pyrazine-carboxylate)<Subscript>3</Subscript> (M = Co<Superscript>+3</Superscript>, Cr<Superscript>+3</Superscript>, and Rh<Superscript>+3</Superscript>)

Abstract Three new isostructural coordination complexes, M(pca)₃, where M = Co (1), Cr (2), or Rh (3) and 2-pyrazine-carboxylate (pca), have been synthesized solvothermally and characterized by single crystal X-ray diffraction and powder X-ray diffraction. In structures 1-3, the pca ligand chelates to the metal centers in a tris-chelating arrangement through proximal nitrogen and oxygen donor atoms. Structures 1-3 are monoclinic and crystallize in the space group C2/C. In structure 1, a = 28.066(13) ?, b = 8.036(4) ?, c = 13.577(6) ?, and β = 90.2(10)°. In structure 2 a = 28.318(3) ?, b = 8.089(4) ?, c = 13.792(12) ?, and β = 90.256(2)°. In structure 3, a = 28.679(4) ?, b = 8.051(13) ?, c=13.847(2) ?, and β = 90.585(2)°. Graphical Abstract Three new isostructural coordination complexes, M(pca)₃, where M = Co, Cr, or Rh and 2-pyrazine-carboxylate (pca), have been synthesized solvothermally and characterized by single crystal X-ray diffraction and powder X-ray diffraction.