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.      

Dinuclear Ir(III) Complex with an Unusual η<Superscript>1</Superscript>:η<Superscript>3</Superscript>-allylic Bridging Ligand from the Double C–H Activation of 2,5-Dimethylthiophene

Abstract  

The unique dinuclear Ir(III) complex (Cp*IrCl)(μ-H)[μ-(η¹:η³-C₆H₆S)](IrCp*) (1) has been synthesized and characterized by NMR spectroscopy (¹H and ¹³C), elemental analysis, and single crystal X-ray diffraction. It is the first structurally determined complex in which an activated thiophene ligand displays an η³-allylic interaction. 1 appears to form from successive C-H bond activations of 2,5-dimethylthiophene, resulting in its bridging the two iridium centers. The η³-allylic interaction occurs with one of the Ir centers and has Ir–C_thio bond lengths ranging from 2.133(5)-2.207(5) ?; the C–C double bond involved in the interaction has a bond length of 1.438(7) ? compared to 1.348(8) ? for the uncoordinated C–C double bond. The 3-carbon of the thiophene ring bridges both iridium centers with bond lengths of 2.036(5) ? and 2.208(5) ?. 1 crystallizes in space group P−1 with cell constants a = 8.6303(6) ?, b = 9.0153(6) ?, c = 18.1089(12) ?, α = 84.728(1)°, β = 87.534(1)°, γ = 64.373(1)°, and Z = 2. The structure was solved by direct methods and refined to R = 0.0363 (F ² > 2σ(F ²)) and wR = 0.0851 (F ²). The NMR data indicate the solution state structure is consistent with the solid state structure.     

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.     

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.     

Crystal Engineering: A Salt of Mellitate Ion,MA<Superscript>−2</Superscript>, with Hydronium,H<Subscript>3</Subscript>O<Superscript>+</Superscript>, Containing π–π Stacks of Neutral Phenazine,PZ, in the Crystal

Abstract  The structure of the benznenehexacarboxylic acid (mellitic acid, MA)––phenanthroline (PL) complex (MA⁻²   2PL⁺¹) consisting of infinite stacks of phenanthroline separated for optimum π–π interactions and sandwiched between MA ribbons suggested a design of models with more significant π–π interactions to produce conducting materials. Phenazine (9,10-diazaanthracene) was considered as a promising choice. The X-ray structure of the complex (MA₁–PZ₄) from MA⁻² and neutral PZ was a major surprise since the complex was not only radically different from MA–PL but also the MA exhibited the rare direct interaction with the base PZ. In a novel arrangement, a continuous chain formed by the linking of the peri carboxylic groups of MA⁻² mediated with hydronium ions, H₃O⁺, supports a 4-fold arrangement of four phenazine molecules where four carboxylic groups are engaged in hydrogen bond formation with one of the nitrogens of each PZ. The running chain of MA⁻² supports the formation of stacks of phenazine molecules which are separated by ~3.39–3.60 ?, well suited for π–π overlap. The proximal placement of such threaded modules enables their transformation to layered stacks thus possibly enhancing their π–π interactions. Crystal structure parameters are: sp. gr. C2/c, a = 13.2819(23) ?, b = 11.3669(20) ?, c = 33.3757(57) ?, β = 96.515(3), R ₁ = 0.0521 for 4,198 data (I > 2σ(I)) and wR ₂ = 0.0828 for all 6,194 data. Graphical Abstract  Dark brown thick crystals from MA and phenazine form the sandwiched module (PZ₂–MA⁻²–PZ₂) that assembles vertically to produce infinite π–π stacks of PZ. Isabella L. Karle (Senior Scientist) is responsible for the structure analysis and discussion. Subramania Ranganathan (Professor) is responsible for design of molecule and synthesis.     

New representative in the sodalite structure type with extraframework anions [AlF<Subscript>6</Subscript>]<Superscript>3−</Superscript>

The crystal structure of new synthetic aluminosilicate |Na_7.38(AlF₆)_0.70(H₂O)_4.88|[(Si_6.74Al_5.26)O₂₄]-SOD, which was obtained by hydrothermal synthesis (T = 650° C, P = 2 Kbar) in the Si-Al-Na-F-H₂O system, has been found by X-ray diffraction (Xcalibur-S-CCD diffractometer, 2θ_max = 64.99°, R = 0.037 for 440 reflections): a = 9.0461(1) Å, sp. gr. P \(\bar 4\)3m, Z = 1, and ρ_calcd = 2.370 g/cm³. The disordered Si,Al-tetrahedral framework (the structural basis of the new compound) is topologically identical to the framework of mineral sodalite. Na⁺ cations, [AlF₆]^3? anions, and H₂O molecules occupy framework voids. The form of fluorine incorporation into the sodalite crystal structure (as octahedral aluminofluoride complexes) has been reliably established for the first time.     

One Novel Three-dimensional Network Constructed from [Mn(4,4′-bip)<Subscript>2</Subscript>(OH<Subscript>2</Subscript>)<Subscript>4</Subscript>]<Superscript>2+</Superscript> Cations and DBA<Superscript>2−</Superscript> Anions via Hydrogen-bonding and π–π Interactions

Abstract One new mononuclear manganese complex of [Mn(4,4′-bip)₂(OH₂)₄](DBA) · 4H₂O (1) (4,4′-bipyridine, 4,4′-bip; H₂DBA, benzene-1,3-dicarboxylic acid) has been obtained from the hydrothermal reaction of MnCl₂ · 4H₂O, 4,4′-bipyridine and H₂DBA in the solvent of H₂O at 140 °C for 3 days, characterized by X-ray analysis, spectroscopic methods, and thermal analysis. Packing diagram shows that the three-dimensional network was formed via hydrogen bonds and strong π–π interactions. Graphical abstract One Novel Three-dimensional Network Constructed from [Mn(4,4′-bip) ₂ (OH ₂ ) ₄ ] ²⁺ Cations and DBA ²⁻ Anions via Hydrogen-bonding and π–π Interactions Ying Liu, Bao Zhang, Jian-min Dou, Da-qi Wang, Da-cheng Li, Lei Zhou One new mononuclear manganese complex of [Mn(4,4’-bip)₂(OH₂)₄](DBA) · 4H₂O (1) (4,4’-bipyridine, 4,4’-bip; H₂DBA, benzene-1, 3-dicarboxylic acid) has been obtained and haracterized by X-ray analysis, spectroscopic methods, and thermal analysis. Packing diagram shows that the three-dimensional network was formed via hydrogen bonds and strong π-π interactions.      

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.     

2D d<Superscript>10</Superscript> Metal Assembly Frameworks: Construction of Metal–organic Architecture with Metal Thiocyanate and Dipyridyl Spacer

Abstract  

A new coordination polymer based on Group IB metal thiocyanates, [Ag₂^I (NCS)₂(dpds)₂]_n (1) (dpds = 2,2′-dipyridyldisulfide), has been synthesized by the pre-assembly method and characterized by X-ray crystallography. In 1, the Ag^I center adopts tetrahedral coordination geometry and the 2-D undulated layers of (4, 4) topology network is formed by dpds ligand with zigzag NCS⁻Ag chains.     

Synthesis and Structure of the Cyclic Borenium Cation 1,1,3,3-tetramethyl-1,3λ<Superscript>4</Superscript>,2-diazaborolidin-1-ium chloride

The solid state structure of an N-heterocyclic borane 1,1,3,3-tetramethyl-1,3λ⁴,2-diazaborolidin-1-ium chloride is reported. This molecule features numerous Cl?H hydrogen bonds.

Graphical Abstract

The crystal structure of 1,1,3,3-tetramethyl-1,3λ⁴,2-diazaborolidin-1-ium chloride shows multiple C–H?Cl interactions in the solid state.

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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.     

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 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.     

Synthesis and Structural Characterization of [Ag(H-dpa) (η<Superscript>2</Superscript>-styrene)]BF<Subscript>4</Subscript>: Comparing Silver and Copper for Olefin Binding

Abstract  

The molecular structure of the complex bis-(2-pyridyl)amine(η²-styrene)silver(I) tetrafluoroborate has been determined. The geometry about the Ag⁺ ion is pseudo-trigonal planar, with coordination sites occupied by the two pyridyl nitrogen atoms and the midpoint of the alkene double bond. Crystal packing of the molecule is influenced by hydrogen bonding of the amine with the tetrafluoroborate anion, in addition to intermolecular Ag⁺···aromatic contacts. ¹H NMR confirms crystallographic data that suggest weak metal to olefin π-backbonding. Crystal data: space group P2₁/n, a = 12.764(3), b = 10.590(2), c = 13.624(3) Å, β = 91.17(3)°, V = 1841.3(7) Å³, Z = 4, R = 0.0453, wR ₂ = 0.1098.     

CdWO<Subscript>4</Subscript> crystal growth and production of a spectrometric detection unit with a large-volume (<Emphasis Type="Italic">V</Emphasis> ≅ 350 cm<Superscript>3</Superscript>) crystal

Large-volume (V ≅ 350 cm³) CdWO₄ single crystals of high optical quality have been grown by the Czochralski method. A scintillation detection unit based on a large CdWO₄ crystal has been produced and its characteristics have been studied.     

Crystal and molecular structure of an ion-pair complex based on [Ni(mnt)<Subscript>2</Subscript>]<Superscript>2−</Superscript> anion and imidazolium derivative cations

A new ion-pair complex, 1-methyl-3-benzylimidazolium bis(maleonitrile-dithiolato) nickelate(II), has been synthesized and characterized by IR spectroscopy, UV-visible spectroscopy and X-ray crystallography. The crystallographic data for the complex: triclinic , a = 8.415(1) Å, b = 9.924(1) Å, c = 11.333(2) Å, = 114.11(1), = 102.46(1), = 100.88(1), V = 801.8(2) ų, Z = 1. The molecular packing pattern showed a completely separated column stacking for cations and anions of the complex along with the b-axis. The anion is not completely planar. The five-membered nickel-containing rings are slightly puckered. The cation, [BzIm]⁺, adopts a conformation where the benzene ring and imidazole ring twisted with the reference plane C10–C11–N3.     

Hydrogen Bonding Deduced α and β Polymorphs of Bis(tetrabutylammonium) Bis(cyclohexylammoinum) β-Octamolybdate, [β-Mo<Subscript>8</Subscript>O<Subscript>26</Subscript>]<Superscript>4−</Superscript>

Abstract  

The title compound, (C₆H₁₄N)₂(C₁₆H₃₆N)₂[β-Mo₈O₂₆] crystallizes in two polymorphs due to different hydrogen bonding self-assembly structures in the solid state. The two polymorphs are of same symmetry and similar cell parameters and inside them the octamolybdate anions are linked to form chains through pairs of N–H···O hydrogen bonds. Minor differences of the conformation of octomolybdate anions and the hydrogen bonding attach positions in the two crystals result in the two polymorphs.     

Synthesis and Crystal Structure of a New Ion-Pair Complex Based on [Ni(tdas)<Subscript>2</Subscript>]<Superscript>2−</Superscript> Anion and Triphenylphosphinium Cation

Abstract  A new ion-pair complex, bis(1-benzyltriphenylphosphinium) bis(1,2,5-thiadiazole-3,4-dithiolato)nickelate(II), [BzTPP]₂[Ni(tdas)₂](1), has been prepared and characterized by elemental analyses, UV, IR, MS spectrum, molar conductivity and single crystal X-ray diffraction. The title complex crystallizes in the triclinic space group P-1, a = 9.098(1) Å, b = 9.666(1) Å, c = 29.573(3) Å, α = 83.81(1)°, β = 81.97(1)°, γ = 78.83(1)°, V = 2,517.5(4) ų, Z = 2. The unit cell contains two [BzTPP]⁺ and two halves of [Ni(tdas)₂]²⁻ anions in which the anion exhibits a quasi-planar structure. The [BzTPP]⁺ cation adopts a conformation where four phenyl rings are twisted to the C–C–P reference plane. The weak cation–cation C–H···π, π···π interactions and anion–cation C–H···N hydrogen bonds between the anion and cation play an important role in the stacking and stabilizing of the title complex. Graphical Abstract  The title new ion-pair complex, bis(1-benzyltriphenylphosphinium) bis(1,2,5-thiadiazole-3,4-dithiolato)nickelate(II), [BzTPP]₂[Ni(tdas)₂](1), contains two [BzTPP]⁺ and two halves of [Ni(tdas)₂]²⁻ anions in which the weak cation–cation C–H···π, π···π interactions and anion−cation C–H···N hydrogen bonds between the anion and cation play an important role in the stacking and stabilizing of the title complex.      

Self-Assembly of a New 1D Coordination Polymer Built of [Nb<Subscript>6</Subscript>Cl<Subscript>12</Subscript>(CN)<Subscript>6</Subscript>]<Superscript>4−</Superscript> and Mn(III) Complexes

Abstract  

A new 1D coordination polymer [Me₄N]₃{[Mn(L)][Nb₆Cl₁₂(CN)₆]}·3MeCN·H₂O (1) (L = acacen ²⁻ = N,N′-bis(acetylacetone)-1,2-ethylenediimine) was synthesized from reaction between [Me₄N]₄[Nb₆Cl₁₂(CN)₆] and [Mn(L)]Cl in acetonitrile. The crystal structure of 1 was determined from single-crystal X-ray diffraction analysis. Compound 1 crystallizes in the tetragonal system, space group I4₁/a (No. 88), a = 30.585(4), c = 27.348(6) ?, V = 25582(7) ?³, Z = 16. Its 1D framework consists of chains formed of metal clusters and Mn(L) complexes linked to each other by Nb–C≡N–Mn–N≡C–Nb linkages. The chains extend along the a and b crystallographic axes and are related to each other by 4₁ screw axis. The chains are held together by [Me₄N]⁺ cations and solvent molecules located in channels running between the chains. 1 and the previously reported 1D coordination polymer [Me₄N]₃{[Mn(5-MeO-salen)][Nb₆Cl₁₂(CN)₆]} (3) differ from each other in terms of their synthesis and their structural characteristics.