The Crystal and Molecular Structure of Dianhydrogossypol

Dianhydrogossypol (4,4′-dihydroxy-5,5′-diisopropyl-7,7′-dimethyl-bis(3H-naphtho[1,8-bc]furan-3-one)) was made by refluxing gossypol in m-xylene. Proton NMR spectroscopy was used to confirm that complete conversion was achieved over a time period of several hours. Single crystals of the compound were obtained by slow evaporation from dichloromethane. Diffraction studies indicate that this crystal form is tetragonal with a I4₁/a space group and with cell dimensions of a = b = 33.8265(4) Å, c = 9.1497(2) Å, V = 10469.4(3) Å³ at 100 K. The structure was solved by direct methods and was refined to an R1 value of 0.0415 on 6,408 independent reflections. Dianhydrogossypol exists as a pair of enantiomers within this structure. The two fused planar ring systems are oriented at a 117° angle to each other (i.e., close to perpendicular), and the isopropyl groups are oriented with the ternary carbon hydrogen atoms pointed inward toward the center of the molecule. Repeating groups of four molecules (of the same chirality) pack to form a helical structure that is supported by intermolecular hydrogen bonds. Each helix is surrounded by four neighboring helices that are composed of molecules of the opposite chirality. The helices form the walls of empty channels that are 5–6 Å wide. As has been found for some gossypol crystal forms, the open-channel structure of dianhydrogossypol might be useful for scavenging or carrying small molecules. Additional NMR studies confirm that dianhydrogossypol can be converted directly to gossypol lactol ethers in the presence of anhydrous alcohols.     

Microwave Assisted Crystal Growth of a New Organic—Decavanadate Assembly: [V10O27(OH)] · 2(C6N2H14) · (C6N2H13) · (C6N2H12) · 2H2O

Microwave synthesis was used to grow single crystals of a new organic–inorganic supramolecular assembly, [V₁₀O₂₇(OH)] · 2(C₆N₂H₁₄) · (C₆N₂H₁₃) · (C₆N₂H₁₂) · 2H₂O, in a very short time compared to the conventional solution technique. In order to generate crystals suitable for single crystal experiments, an equimolar mixture of reactants and a few hours of microwave heating are required. Although non-merohedral twinning is an inherent problem, the crystal structure can be solved and refined in the orthorhombic space group Pna2 ₁ with a = 20.972(4) Å, b = 10.3380(14) Å, c = 20.432(3) Å, Z = 4, with an excellent result, R(F²) = 0.0431. The assembly is hydrogen bond-assisted and built up of the monoprotonated decavanadate and 1,4-diazabicyclo[2.2.2]octane of various degrees of protonation. The number and location of protons on both the inorganic and organic motifs govern the formation of the extensive hydrogen bonding network, which in turn regulates the assembly architecture.     

X-ray structure and spectroscopic properties of some lanthanides(III) complexes derived from 2,6-diacetylpyridine-bis(benzoylhydrazone)

A series of trivalent lanthanide complexes of type [Ln(L) NO₃)(S)_n](NO₃)_m(S^′)_n, have been synthesized by the reaction of 2,6-diacetylpyridine-bis-(benzoylhydrazone) (H₂L) with lanthanide(III) nitrates in ethanol. These complexes have been characterized by analysis, molar conductance, magnetic measurements, infrared spectral studies and X-ray diffraction. The analytical data revealed the formation of 1:1 (metal:ligand) stoichiometry. Molar conductance in dmf gives 2:1 electrolytes in all the complexes. Magnetic moment values are close proximity of the Van Vleck values. IR study suggests the coordination of the ligand through the azomethine and the oxygen of the hydrazonic moiety. The nitrate ion is also found to be bidentate in all the complexes. The crystal structures were determined. 6, C₂₇H₃₁N₆O₇S₂Gd: a=b=8.6821(4) Å, c=84.363(5) Å, tetragonal P4₁2₁2 and Z=8. bf 7, C₂₅H₂₅N₆O₆SDy: a=11.750(3) Å, b=13.250(3) Å, c=36.000(6) Å, β=98.50(2), monoclinic, C2/c, Z=8. 9, C₂₄H₂₅N₆O₇Yb: a=10.750(2) Å, b=17.750(3) Å, c=14.250(4) Å, β=99.00(2), monoclinic, P2₁/n, Z=4. In these complexes the lanthanide ion assumes a nine coordinated geometry for Gd and an eight coordinated geometry for Dy and Yb.     

Synthesis of single azo disperse dye containing double ester and determination of crystal structure

The synthesis, crystal structure analysis and characterization of a monoazo dye, 4-((2,6-dichloro-4-nitro phenyl)azo)-N-(diacetyl oxygen ethyl)aniline, are reported. The dye crystallised in the triclinic system, space group P-1 with a=8.1663(3) Å, b= 9.4222(3) Å, c=15.4694(5) Å, α=78.9130(10)°, β=75.019(2)°, γ=70.787(2)°, V=1078.26(6) ų and Z=2. There is only one molecule in the asymmetric unit. The dihedral angle between the two phenyl rings is 53.4 Å. In the crystal structure, intermolecular C-H…O hydrogen bonds link the molecules into centrosymmetric dimers, forming R₂₂(30) ring motifs, in which they may be effective in the stabilization of the structure. Between the phenyl rings, the π…π stacking (interactions) may further stabilize the structure.     

A novel double-helical-chain coordination polymer constructed from 2,2′-biphenyldicarboxylate-linked binuclear-copper motif

The first 1-D double-helical-chain coordination polymer, [(H₂O)Cu(BPDC)] (2,2^′-biphenyldicarboxylate), based upon the binuclear square pyramidal copper(II)-pair motifs has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction technique. [(H₂O)Cu(BPDC)] crystallized in orthorhombic crystal system, space group Cmca with unit cell dimensions a=21.073(6) Å, b=7.118(2) Å and c=17.670(5) Å, Z=8.     

The first example of half-sandwich cobalt(III) complex with hydrotris(pyrazolyl)borate ligand

This paper presents the synthesis, crystal structure and spectroscopic properties of a novel half-sandwich mononuclear cobalt(III) complex with hydrotris(3,5-dimethylpyrazolyl)borate ligand and thiocyanate [Tp^*Co(Hpz^*)(NCS)₂]·H₂O·CH₃OH (Tp^*: hydrotris(3,5-dimethyl- pyrazolyl)borate, Hpz^*: 3,5-dimethylpyrazole). The structure was determined by X-ray diffraction. The complex crystallizes in the monoclinic system, space group C_c, a=18.591(6) Å, b=10.536(3) Å, c=17.568(5) Å, β=11.284(5)°, Z=4, R₁=0.0501, wR₂=0.1179. The cobalt(III) ion in the complex is six-coordinated with nitrogen atoms, three from Tp^*, two from pyrazole and two from two thiocyanates, to form octahedral environment. The hydrogen atoms of O(2) of water molecule are connected by hydrogen bonds with S atoms of two adjacent complex molecules to form 1-D chains. The hydrogen atom of N(8) of complex molecule is connected by hydrogen bond with methanol. The spectroscopic results are consistent with the crystallographic study.     

One-pot template synthesis and crystal structure of two new polyaza copper(II) complexes

A new 14-membered hexazamacrocyclic copper(II) complex [Cu(H₂L¹)](ClO₄)₄(L¹=1,8-bis(2-aminoethyl)-1,3,6,8,10,13-hexaazacyclotetradecane) has been prepared by the one-pot reaction of ethylenediamine and formaldehyde in the presence of the Cu(II) ion. The crystal structure of [Cu(H₂L¹)](ClO₄)₄ was determined by X-ray diffraction. It crystallizes in the triclinic space group P−1 with a=12.118(2) Å, b=12.438(2) Å, c=12.466(2) Å, α=102.26(1)°, β=112.82(1)°, γ=111.51(1)°, and Z=2. The coordination geometry around the copper(II) ions is axially elongated octahedral with four nitrogen atoms of the macrocycle [Cu–N 2.012(7) Å for Cu(1) and 2.013(6) Å for Cu(2), average value] and two oxygen atoms of two ClO₄⁻ anions [Cu–O=2.550 Å for Cu(1) and 2.601(6) Å for Cu(2)]. [CuL²](ClO₄)₂(L²=3,7-bis(2-aminoethyl)-1,3,5,7-tetraazabicyclo[3,3,2]decane) with a novel tetraazabicyclic ligand was obtained from the same reaction system as an additional product. Crystal structure of [CuL²](ClO₄)₂: monoclinic space group Cc, a=16.393(3) Å, b=8.8640(18) Å, c= 13.085(3) Å, β=105.01(3)°, and Z=4.     

The synthesis and crystal structure of [M{H2B(tz*)2}2(H2O)] (M=Cu,Zn and tz*=3,5-dimethyl-1,2,4-triazole)

New ligand [KH₂B(tz^*)₂] (tz*=3,5-dimethyl-1,2,4-triazolyl) has been synthesized and the reactions of two different metal salts (copper and zinc) with the new ligand in agar gave two similar crystalline polymorphic forms: [Cu{H₂B(tz^*)₂}₂(H₂O)] (1) and [Zn{H₂B(tz^*)₂}₂(H₂O)] (2). A single crystal X-ray study revealed that the compound 1 was the monoclinic system with space group C2/c and a=8.462(3) Å, b=14.039(6) Å, c=19.991(8) Å, β=94.622(7)°, Z=4, R₁=0.0451, wR₂=0.1110. And the compound 2 was the monoclinic system with space group C2/c and a=8.4214(4) Å, b=13.8765(7) Å, c=20.2969(6) Å, β=95.615(2)°, Z=4, R₁=0.0667, wR₂=0.1375. The metal(II) ion in the complex is five-coordinated with four nitrogen atoms which come from triazolyl and one oxygen atom which come from water molecular. In both compounds, the hydrogen atoms of water molecule are connected by hydrogen bonding with N atoms of two adjacent complex molecules to form 2-D planes. The spectroscopic results are consistent with the crystallographic study.     

Reversible ferroelectric phase transition of 1,4-diazabicyclo [2,2,2]octane N,N′-dioxide di(perchlorate)

1,4-Diazabicyclo [2,2,2]octane N,N′-dioxide di(perchlorate), C₆H₁₄N₂O₂^2 +·2ClO₄⁻, was synthesized and separated as colorless block crystals. Differential scanning calorimetry detected that this compound underwent a reversible phase transition at ca. 216 K with a hysteresis of 5.5 K width, which was also confirmed by dielectric measurements. Single crystal X-ray diffraction data suggested that there was a transition from a room temperature phase with the space group of P2₁/c (a = 6.815(7) Å, b = 12.644(13) Å, c = 8.676(9) Å, β = 101.466(15)°, V = 732.7(13) ų, Z = 4) to a low temperature one with a space group of P2₁ (a = 9.892(8) Å, b = 12.559(10) Å, c = 17.401(13) Å, β = 92.065(8)°, V = 2160(3) ų, Z = 2). Crystallographic analysis showed that it belonged to chiral space group P2₁ with ferroelectric behaviors, and a typical ferroelectric feature of electric hysteresis loop was obtained in the low temperature phase. The disorder-order transformation of H₂-Dabcodo^2 + cation and ClO₄⁻ anion as well as the change of hydrogen bonds may drive the phase transition.     

A novel two-dimensional chiral coordination polymer: bis(S-(-)-lactate)zinc(II)

The synthesis and X-ray characterization of a novel chiral two-dimensional condensed metal–organic coordination polymer, bis(S-(-)-lactate)zinc(II) (1), are reported. Its crystal structure determination shows that a chiral cavity with approximate dimensions of 5.4×5.4 Ų is present. Crystallographic data for 1, C₆H₁₀O₆Zn, monoclinic P2₁, a=7.4440(15), b=7.4550(15), c=7.4550(15) Å, β=95.73(3)°, V=429.48(15) ų, R₁=0.0272, wR₂=0.0751.     

Synthesis,Crystal Structure of Tetra-Nuclear Macrocyclic Cu(II) Complex Material and Its Application as Catalysts for A3 Coupling Reaction

A novel tetra-nuclear macrocyclic Cu(II) complex has been synthesized by the reaction of cupric acetate monohydrate with N-acetyl-l-phenylalanine and 4,4-bipyridine in water/ethanol (v:v = 1:1) solution, and characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. The results show that the Cu(II) complex belongs to monoclinic, space group P ₂₁ with a = 14.993(3) Å, b = 14.831(3) Å, c = 22.262(4) Å, β = 99.37(3)°, V = 4884.2(16) Å³, Z = 2, D _c  = 1.420 μg m^?3, μ = 0.942 mm^?1, F(000) = 2,160, and final R ₁ = 0.0701, ωR ₂ = 0.1905. The molecules form three dimensional tubular structures by the interaction of hydrogen bonds and π–π interaction. The A³ coupling reaction of phenylacetylene, aldehyde and amine (piperidine) in the presence of Cu(II) complex as an efficient heterogeneous catalyst has been studied. The catalyst displayed high activity and afforded the corresponding propargylamines with excellent yields. The Cu(II) complex catalyst was reused three times without significant loss of its catalytic activity.     

Phonon dispersion curves and elastic properties of polyoxymethylene single crystals

By growing large single crystals of fully deuterated polyoxymethylene (CD₂O)_n, it has been possible to observe phonons for a number of different branches of the phonon dispersion curves using coherent neutron inelastic scattering. Using a hexagonal approximation for this crystal, four of the five independent stiffness constants at 300K have been determined as C₁₁ = 1.30 × 10¹¹; C₁₂ = 6.32 × 10¹⁰; C₃₃ = 1.64 × 10¹²; C₄₄ = 2.64 × 10¹⁰ dyne cm^?2 from the acoustic slopes. The hexagonal approximation is valid to within 10% and this is discussed. The inherent disorder and large size of the unit cell along the c axis (17.35 Å) have restricted modelling of the lattice dynamics by methods such as the atom-atom potential method, and made phonon measurements impracticable in some regions of the momentum transfer-energy transfer space.     

Synthesis,Structure and Fluorescence Spectra Study of a Supramolecular Zinc(II) Complex

A new structural supramolecular zinc(II) complex (1), [Zn(H₂O)₆]²⁺[Zn(4,4′-bipy)(SO₄)₂(H₂O)₂]^2?[Zn(4,4′-bipy)(SO₄)(H₂O)₃] is synthesized in mixed solvent system at room temperature. The complex was characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. Structural analyses reveal that the complex is crystallized in the triclinic system with P1 space group. Cell parameters: a = 7.3145 (15) Å, b = 11.194 (2) Å, c = 11.442 (2) Å, α = 72.48 (3)°, β = 73.78 (3)°, γ = 83.39 (3)°, V = 857.3 (3) ų. Zn atoms (Zn1, Zn2 and Zn3) are all six-coordinated, however, the coordination environments of them are different. Owning to the abundant intro- and inter- hydrogen bonding interactions, the adjacent molecular units were connected to form a 2D supramolecular chain, and the two adjacent chains were furthermore linked to form a 3D supermolecular network structure via the hydrogen bonds. In addition, it is found that the complex has potential applications as fluorescent-emitting materials due to the strong fluorescence.     

Synthesis and single-crystal structures of fully dehydrated fully Sr2+-exchanged zeolite Y (FAU) and its benzene sorption complex, |Sr37.5|[Si117Al75O384]-FAU and |Sr37.5(C6H6)33(H2O)15|[Si117Al75O384]-FAU

Single crystals of zeolite Y, |Na₇₅|[Si₁₁₇Al₇₅O₃₈₄]-FAU, were Sr²⁺ ion exchanged and fully dehydrated to generate |Sr_37.5|[Si₁₁₇Al₇₅O₃₈₄]-FAU (crystal 1) and next, benzene adsorbed to generate |Sr_37.5(C₆H₆)₃₃(H₂O)₁₅|[Si₁₁₇Al₇₅O₃₈₄]-FAU (crystal 2, partially dehydrated). Crystal 1 was prepared by ion exchange in a flowing stream of aqueous 0.05 M Sr(ClO₄)₂ for 3 days followed by dehydration at 673 K and 1 × 10^?6 Torr for 2 days. To prepare the benzene sorption complex (crystal 2), another dehydrated |Sr_37.5|[Si₁₁₇Al₇₅O₃₈₄]-FAU crystal was exposed to 50 Torr of benzene for 3 days at 294 K followed by evacuation for 30 min. at this temperature and 5 × 10^?5 Torr. Their structures were determined crystallographically at 100(1) K using synchrotron X-radiation in the cubic space group Fd $ \bar{3} $ m. They were refined to the final error indices R ₁/wR ₂ = 0.051/0.125 and 0.057/0.154 using 598 and 590 reflections with F _o > 4??(F _o) for crystals 1 and 2, respectively. In crystal 1, about 37.5 Sr²⁺ ions per unit cell are found at an unusually large number of crystallographically distinct positions, six. Eight Sr²⁺ ions per unit cell are at the centers of the double 6-rings (D6Rs, site I). Five additional Sr²⁺ ions are near site I. The site-I?? positions (in the sodalite cavities opposite D6Rs) are occupied by 2.5 Sr²⁺ ions per unit cell. Two Sr²⁺ ions are located at site II?? in the sodalite cavity. The remaining twenty Sr²⁺ ions are found at two nonequivalent sites II (in the supercages) with occupancies of 9 and 11 ions per unit cell, respectively. Each of these Sr²⁺ ions coordinates to three framework oxygens. In this crystal, all sites are only sparsely occupied. In crystal 2, all Sr²⁺ ions are located at four crystallographic sites and 33 benzene molecules are found at two distinct sites within the supercages. One Sr²⁺ ion is at the center of the D6R. Fifteen Sr²⁺ ions are located at site I??. The remaining 21.5 Sr²⁺ ions are found at two nonequivalent sites II with occupancies of 19 and 2.5 ions per unit cell. Nineteen benzenes lie on threefold axes in the supercages, where they interact facially with the latter 19 site-II Sr²⁺ ions; occupancy = 19 molecules/32 sites. The remaining fourteen benzene molecules are found in 12-ring planes; occupancy = 14 molecules/16 sites. Each hydrogen of these 14 benzenes is ca. 2.9 Å from six 12-ring oxygens.     

1D Coordination Polymer from Tetraaza Macrocyclic Nickel(II) Complex and 1,2,3,4-Cyclobutanetetracarboxylic Acid

The self assembly of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) and 1,2,3,4-cyclobutanetetracarboxylic acid (H₄cbtc) acid generates a 1D coordination and 2D hydrogen-bonded polymer [Ni(L)(H₂cbtc)₂·3H₂O] _n (1). Complex 1 is characterized by X-ray crystallography, spectroscopy and magnetic susceptibility. Each nickel(II) ion has a distorted octahedral coordination environment with the four secondary amines of the macrocycle in which two carboxylate anions of the H₂cbtc^2? ligand have assembled around each nickel center. The compound crystallizes in the triclinic system P-1 with a = 9.715(3) Å, b = 12.891(5) Å, c = 13.903(6) Å, α = 72.64(2)°, β = 75.70(3)°, γ = 73.27(3)°, V = 1566.6(10) ų, Z = 2. The electronic spectrum of 1 indicates a high-spin octahedral environment. The magnetic behavior of 1 reveals a weak intramolecular antiferromagnetic interaction with J = ?1.23(1) cm^?1.     

Preparation and structural study of fully dehydrated,highly Mg2+-exchanged zeolite Y (FAU,Si/Al = 1.56) from undried methanol solution

Single-crystal of fully dehydrated, Mg²⁺-exchanged zeolite Y, |Mg_34.5Na₆|[Si₁₁₇Al₇₅O₃₈₄]-FAU (Si/Al = 1.56), was successfully prepared from undried methanol solution (water concentration 0.02 M). A crystal of Na-Y was treated with 0.05 M MgCl₂ ·6H₂O in the solvent at 333 K, followed by vacuum dehydration at 723 K and 1 × 10^?6 Torr for 2 days. Its structure was determined by single-crystal synchrotron X-ray diffraction techniques, in the cubic space group \(Fd\overline{3} m\) at 100 K. It was refined to the final error indices R ₁/wR ₂ = 0.0587/0.2210 with 1,294 reflections for which F _o > 4σ(F _o). In the structure of |Mg_34.5Na₆|[Si₁₁₇Al₇₅O₃₈₄]-FAU, 34.5 Mg²⁺ ions per unit cell are found at four different crystallographic sites: 15 per unit cell are located at site I at the center of the hexagonal prism [Mg–O = 2.216(2) Å], two are at site I’ in the sodalite cavity near the hexagonal prism [Mg–O = 2.20(3) Å], only one is located at site II’ in the sodalite cavity [Mg–O = 2.197(23) Å], and the remaining 16.5 are at site II near single 6-oxygen rings in the supercage [Mg–O = 2.103(3) Å]. The residual 6 Na⁺ ions per unit cell are found at site II [Na–O = 2.218(7) Å]. No water molecules are found in this structure.     

Model bulk Mo–V–Te–O catalysts for selective oxidation of propane to acrylic acid

The crystal structures and chemical compositions of the M1 and M2 phases proposed as active and selective in propane oxidation to acrylic acid over the bulk mixed Mo–V–Te–O catalysts were investigated by the transmission electron microscopy, coupled with energy dispersive analysis of X-rays. The results revealed that the crystal structure of the M1 phase is orthorhombic with space group Pbca, lattice parameters a=21.25 Å, b=27.14 Å, c=4.03 Å and composition Mo_0.64V_0.32Te_0.1O_3.05 (Mo/V ∼2), whereas M2 is hexagonal with space group P6mm, lattice parameters a=7.10 Å, c=4.05 Å and composition Mo_1.79V_1.85Te_0.1O_11.36 (Mo/V ∼1). The M1 phase was dominant in the Mo–V–Te–O catalyst. The results obtained indicated that the bulk Mo–V–Te oxides represent a well-defined model catalytic system for the studies of the surface molecular structure-activity/selectivity relationships in propane oxidation to acrylic acid.     

A novel cobalt(II) acylpyrazolonate complex with intermolecular hydrogen bond: Synthesis,structure and properties

A new cobalt complex, [Co(L)₂·(H₂O)₂](HL = 4-hexanoyl-3-methyl-1-phenyl-1H -pyrazol-5(4H)-one), was synthesized by us. The complex was characterized by single crystal X-ray diffraction, IR, UV, fluorescence spectra and thermogravimetric analysis. The results of characterization showed that the crystal is monoclinic system with crystal parameters: a = 15.2439(12) Å, b = 7.4101(6) Å, c = 15.7381(18) Å, and Z = 2, S = 1.074. It was found that the Co²⁺ is located in the inversion center of the complex. The Co(II) had an ideal octahedral coordination environment with four oxygen atoms of HL ligands in the equatorial plane and two water molecules in axial positions. The complex exhibits yellow emission as the result of the fluorescence from the intraligand emission excited state.     

Preparation,Infra-red,MAS-NMR and Structural Characterization of a New Copper Based Inorganic–Organic Hybrid Compound: [C<Subscript>5</Subscript>H<Subscript>6</Subscript>N<Subscript>2</Subscript>Cl]<Subscript>2</Subscript>CuCl<Subscript>4</Subscript>

The ionic salt [2(C₅H₆N₂Cl)⁺], [CuCl₄]^2? complex of copper(II) has been synthesized and characterized. The X-ray diffraction analysis with a single crystal of this compound showed that the title compound (4-amino-2-chloropyridinium)₂CuCl₄ [(CAP)₂CuCl₄], crystallized at room temperature in the monoclinic system, space group C_2/c (N°.15) and the following : a = 16.0064 (2) Å; b = 7.7964 (10) Å; c = 14.7240 (2) Å; β = 102.497 (10)°; V = 1793.91 (4) ų and Z = 4. The structure was solved by using 1,589 independent reflections down to R value of 0.021. The unit cell is made up of tetrachlorocuprate(II) anions and 4-amino-2-chloropyridinium cations linked together by an extensive hydrogen bond network of types N–H···Cl (N: pyridinium) and N–H···Cl (N: amine), and cation-lone pair of nitrogen element interactions. Solid state NMR spectra showed one and five isotropic resonances, ⁶³Cu and ¹³C, respectively, confirming the solid state structure determined by X-ray diffraction. Impedance spectroscopy study, reported for single crystal, revealed that the conduction in the material was due to a hopping process. This work aims to reveal the thermal properties of a new copper(II) based organic–inorganic hybrid and the conductivity properties that these compounds exhibit.