TEM studies on single crystal structure of syndiotactic poly(propene-co-butene-1)s

Themorphologies and structures of single crystals of syndiotactic poly(propene-co-1-butene) (PPBU) with 1-butene contents of 2.6, 4.2, 9.9, 16.2, and 47.9 mol % are studied by transmission electron microscopy and electron diffraction. The electron diffraction results show that the 1-butene units are included in the crystalline phase of the sPP homopolymer. A small amount of 1-butene (<4.2 mol %) has no significant influence on the antichiral chain packing of sPP. With increasing content of 1-butene units, an increasing packing disorder is observed in the PPBU copolymers. The antichiral packing model is, however, always the predominant chain packing structure of the copolymers with the analyzed composition. Bright-field electron microscopy observation shows that the PPBU single crystals exhibit always regular rectangular or lathlike shapes with preferred growth direction along their crystallographic b-axes owing to their packing features. The incorporated 1-butene units influence the crystallization behavior of sPP distinctly. With the increase of the 1-butene units, the aspect ratio of the single crystals increases. Furthermore, the typical transverse microcracks and ripples of the highly stereoregular sPP are no more so prominent for the copolymers. The microcracks are occasionally observed in the single crystals of copolymers with low 1-butene content (less than or equal to4.2 mol %), while transverse ripples are only seen in the crystals of the copolymer having a 1-butene content of 9.9 mol %. With a further increase in the content of 1-butene units, the copolymers behave like the low stereoregular sPP, where neither cracks nor ripples are observed any more.

Hydrothermal synthesis and crystal structure of an unusual compound: [Cu(en)(2)](4)[(SiMo8V4O40)-O-V((VO)-O-IV)(2)][MoO4](2)center dot 5H(2)O

A novel compound [Cu(en)(2)](4)[(SiMo8V4O40)-O-v(V-IV O)(2)] [MoO4](2) . 5H(2)O has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Black crystals crystallize in the tetragonal. system, space group 14/m, a = b = 14.019(2) Angstrom, c = 20.341(4) Angstrom, V = 3997.9(11) Angstrom(3), Z = 2, lambda(MoKalpha) = 0.71073 Angstrom (R(F) = 0.0443 for 1819 reflections). Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range of 1.76 < theta < 24.98degrees using the omega-scan technique. The structure was solved by the direct method and refined by the full-matrix least squares on F-2 method using the SHELXL-97 software. X-ray crystallographic study showed that the title compound contained a bicapped alpha-Keggin fragment [SiMo8 (V4O40)-O-v((VO)-O-IV)(2)](4-) polyoxoanion.

Hydrothermal synthesis and X-ray single crystal structure of bimetallic cluster complex [{Co(phen)(2)}(2)V4O12]center dot H2O

A new bimetallic cluster complex with the formula [{Co(phen)(2)}(2)V4O12](H2O)-H-. was synthesized from the hydrothermal reaction of V2O5, H2C2O4, Co(NO3)(2), 1,10-phenanthroline (phen), (C4H9)(4)NOH and water. The compound crystallizes in an orthorhombic system with space group Pbcn and unit cell parameters a = 19.106(3) Angstrom, b = 15.250(3) Angstrom, c = 16.321(2) Angstrom, V = 4755.4(13) Angstrom(3), Z = 4 and R = 0.0318. The bimetallic cluster complex [{Co(phen)(2)}(2)V4O12](H2O)-H-. is composed of a discrete V4O124- cluster eovalently attached to two [Co(phen)(2)](2+) fragments and the discrete hexanuclear bimetallic clusters of [{Co(phen)(2)}(V4O12)-V-2](H2O)-H-. are further extended into interesting three-dimensional supermolecular arrays via pi-pi stacking interactions of phen groups. Other characterizations by elemental analysis, IR, and thermal analysis are also described.

Photochemical synthesis, properties and X-ray crystal structure of tetrabutylammonium dodecamolybdophosphate heteropoly blue

The title heteropoly blue, (Bu4N)(6)H-10 [(PMo11MoO40)-Mo-VI-O-V](4) . H2O has been photochemically synthesized and characterized with elemental analysis, solid diffusion reflectance electronic spectra, CV, ESR, XPS, IR spectra, conductivity measurement and X-ray single crystal analysis. The crystallographic data for C96H218Mo48N6O169P4 are as follows: M-r = 8889.76, triclinic, P (1) over bar, a = 1.4142 (3) nm, b = 2.6027 (5) nm, c = 2.6403(5) nm, alpha = 113.96(3)degrees, beta = 90.05(3)degrees, gamma = 105.71(3)degrees, V = 8.481 (3) nm(3), Z = 1, D-c = 1.741 g/cm(3), F (000) = 4264, mu = 1.798 mm(-1). The X-ray crystal structure analysis reveals that there Is one independent molecule in the unit cell of the title heteropoly blue which contains four mixed-valence heteropoly anions, six tetrabutylammonium cations and one water molecule. Its molecular structure possesses a centrosymmetrical arrangement in the unit cell. The phosphorus atom is In the crystallographic inversion center of the heteropoly anion and the eight oxygen atoms surrounding central phosphorus atom comprise of a distorted hexahedron. Heteropolyanion has two equal sets of PO4 tetrahedron. The PO4 tetrahedron and the MoO6 octahedron in the polyanion are greatly distorted.

Synthesis and crystal structure of cyclopentylindene rare earth complex (C5H9C9H6)(3)SMCl-Li+ (THF)(4)

Rare earth complex (C5H9C9H6)(3)SmCl-Li+ (THF)(4)( I ) was synthesized by reacting anhydrous SmCl3 with two equivalents of C5H9C9H6Li. From mix-solvent of THF and hexane, red color single crystals were obtained. The crystal belongs to a cubic system, space group P2(1)3 with unit cell parameters a= b=c= 1. 754 0(2) nm, alpha=beta=gamma=90degrees, V=5. 396 4(11) nm(3), Z = 4. The ten-coordinated samarium atom is bonded to three cyclopentylindenyl rings and a chlorine atom to form the anionic part of the title complex, ring centroids and the chlorine atom form a tortured tetrahedron around samarium. In the cationic part, lithium atom coordinates to four oxygen atoms of THF molecules to form a normal tetrahedron. The Sm-C(within the same ring) distance varies from 0. 268 to 0. 299 nm.

Synthesis and crystal structure of 3-methoxycarbonylethyltin tetrachlorides anion

The anion of MeO2CCH2CH2SnCl4 - was obtained by decomposing the yellow solution of MeO2CCH2CH2SnCl3.(2-OHC6H4CH=NC6H5) by standing for 15 days, which is the product of 3-methoxy-carbonylethyltin trichlorides with Schiff base (2-OHC6H4CH=NC6H5). The title compound was characterized by elemental analysis, IR. H-1 NMR,C-13 NMR and X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P2cn, a=7.852(2), b=12.236(1),c=16.952(4)Adegrees, V=1628.7 Angstrom(3), Z=4, D-c=1.79g/cm(3) F(000)=860, mu=22.2cm(-1), R=0.0449, Rw=0.0382. The title compound exists as a discrete molecule, and the tin atom attains a distorted octahedral geometry via the coordination of intramolecular carbonyl oxygen and chloride ion. The coordination number of tin atom is 6.

Single-crystal X-ray structure and properties of K-10[Ni-4(H2O)(2)(AsW9O34)(2)]center dot 4H(2)O

The rational synthesis and the structural and magnetic characterization of a nickel cluster are presented. The compound comprises a rhomblike Ni4O16 group encapsulated between two-heptadentate tungstoarsenate ligands [AsW9O34](9-). The crystal structure of K-10[Ni-4(H2O)(2)(AsW9O34)(2)](.)4H(2)O was solved in monoclinic, P2(1)/n symmetry, with a = 12.258(3) Angstrom, b = 21.232(4) Angstrom, c = 15.837(3) Angstrom, beta = 92.05(3)degrees, V = 4119.1(14) Angstrom(3), Z = 2, and R = 0.0862. The crystal structure of the Ni(II) derivative was compared with that of the Cu(II), Zn(II), Co(II) and Mn(II) derivatives. The Ni4O14(H2O)(2) unit in the compound shows no Jahn-Teller distortion. On the other hand, the Ni(II) derivative shows ferromagnetic exchange interactions within the Ni4O16 group (J = 7.8 cm(-1), J' = 13.7 cm(-1)) and an S = 4 ground state, the highest spin state reported in a heteropoly complex. Its redox electrochemistry has been studied in acid buffer solutions using cyclic voltammetry. It exhibited two steps of one-electron redox waves attributed to redox processes of the tungsten-oxo framework. The new catalyst showed an electrocatalytic effect on the reduction of NO2-.

Synthesis, characterization and crystal structure of a charge transfer salt based on 1.3-cyclopentadiene tetrabutylammoniumdodecamolybdosilicoate

A charge transfer salt, (Bu4N)(4) (C5H6)[(HSiMo11MoO40)-Mo-VI-O-V] has been photochemically synthesized from (Bu4N)(4)SiMo12O40 and 1.3-cyclopentadiene and Characterized, by elemental analysis, IR spectra, solid diffusion reflectance electronic spectra, CV and ESR. The X-ray crystal structure revealed that the title complex crystal data are as follows: triclinic, space group P (1) over bar, a = 14.347(3), b = 14.423(3), c = 27.158(5) Angstrom, alpha = 96.90(3), beta = 104.18(3), gamma = 98.20(3)degrees, V = 5322(2) Angstrom (3), Z = 2, M-r = 2855. 30, D-c = 1.782g.cm(-3), F(000) = 2860, R = 0.0719, wR = 0.198. The title compound is composed of 1.3-cyclopentadiene, four tetrabutylammonium and [(SiMo11MoO40)-Mo-VI-O-V](4-) anion.

Synthesis and crystal structure of a new supermolecular compound: [C12H24O6][H3PMo12O40]center dot 22H(2)O (C12H24O6=18-crown-6)

The title compound, [C12H24O6][H3PMo12O40]. 22H(2)O, was synthesized by the self-assembly of 18-crown-6 (abbreviated as C12H24O6 or 18C6) and H3PMo12O40 in the mixed solvent of CH3OH and CH3CN, and was characterized by IR, H-1 NMR and Xray diffraction for the first time. Crystal data: Triclinic, P (1) over bar, a = 13.428(3) Angstrom, b = 13.557(3)A, c = 14.642(3) Angstrom, a = 105.39(3)degrees, beta = 90.06(3)degrees, gamma = 119.56(5)degrees, V = 2207.5(8) Angstrom(3), Z = 1, R1 = 0.0719, wR2 = 0.1990. It has a disordered alpha-Keggin PMo12O403- anion, which contains the strong alternating short (mean 1.844 Angstrom) and long (mean 1.958 Angstrom) Mo-O-Mo bonds. In the unit cell, crown ethers and molybdophosphates are alternatively arranged in good order along c-axis. An oxonium ion is located at the center of a crown ether molecule., Oxonium ion interacts with 18C6 by the means of hydrogen bonds (mean 2.7771 Angstrom), which are electrostatic or resonant. The observations show the existence of [H3O(C12H24O6)](+) (C) 2000 Elsevier Science B.V. All rights reserved.

Simultaneous determination of both the calibration constant in an electrochemical quartz crystal microbalance and the active surface area of a polycrystalline gold electrode

A novel method is employed for the simultaneous determination of both the calibration constant of an electrochemical quartz crystal microbalance (EQCM) and the active surface area of a polycrystalline gold electrode. A gold electrode: is immersed into a 1 mM KI/1 M H2SO4 solution and on which forms a neutral monolayer. The adsorbed iodine can then be completely oxidized into IO3-. The active surface area of a gold electrode can be obtained from the net electrolytic charge of the oxidation process, and the calibration constant in the EQCM can be calculated from the corresponding frequency shift. The result shows that this method is simple, convenient and valid. (C) 2000 Elsevier Science S.A. All rights reserved.

Synthesis and crystal structure of triphenyltin-2-(1,2-ethylenedithio) methylene-3-oxo-5-aryl-4-pentenicate

Nine triphenyltin - 2 - (1,2 - ethylenedithio) methylene - 3 - oxo - 5 - aryl - 4 - pentenicates were synthesized. The crystal structure of the title compound 3b (C33H28O3S2Sn) was determined by X - ray diffraction analysis. The crystal belongs to triclinic system, space group P(1)overbar with a = 0.9074 (2) nm, b = 1.6809(3)nm, c = 2.1834(4)nm, alpha =77.57(3)degrees, beta = 88.04(3)degrees, gamma = 89.47(3)degrees, V = 3.2503nm(3), Z = 2, R = 0.0592. In crystal of 3b, there exist intramolecular 0-Sn coordination bonds, with carboxylate group acting as a bidentate ligand: Sn(1)-0(1) = 0.2086(5) and Sn(1)-0(2) = 0.2594nm, having a deformed trigonal bipyramidal geometry.

Hydrothermal synthesis and crystal structure of [{Cu(2,2 '-bpy)(2)}(2)Mo8O26]: a beta-octamolybdate cluster covalently bonded to two {Cu(2,2 '-bpy)(2)}(2+) coordination complexes via bridging oxo groups

An organic-inorganic hybrid solid, (Cu(2,2'-bpy)(2))(2)Mo8O26, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Dark green crystals crystallize in the orthorhombic system, space group Pna21, a = 24.164(5), b = 18.281(4), c = 11.877(2) Angstrom, alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees, V= 5247(2) Angstrom (3), Z = 4, lambda (MoK alpha) = 0.71073 Angstrom (R(F) = 0.0331 for 5353 reflections). Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.69 degrees < theta < 25.04 degrees using the omega -scan technique. The structure was solved by the direct method and refined by full-matrix least squares on F-2 using SHELXL-93. The structure of this compound consists of discrete (Cu(2,2'-bpy)(2))(2)Mo8O26 clusters, constructed from beta -octamolybdate subunits ((Mo8O26)(4-)) covalently bonded to two (Cu(2,2'-bpy)(2))(2+) coordination complexes via bridging oxo groups that connect two adjacent molybdenum sites. (C) 2001 Academic Press.

Synthesis and crystal structure of a novel compound: [H3PMo12O40][CO(NH2)(2)](3)center dot-5H(2)O

The title compound, [H3PMo12O40][CO(NH2)(2)](3). 5H(2)O, was synthesized and characterized by IR, C-13 NMR and X-ray diffraction. This is the first example of a urea-heteropoly acid species. Crystal data: monoclinic, C2/c, a = 17.790(4) Angstrom, b = 17.158(3) Angstrom, e = 25.512(5) Angstrom, beta = 100.65(3)degrees, V = 8514(3) Angstrom (3), Z = 6, R-1 = 0.0437, wR2 = 0. 1092. In the unit cell, the urea molecules occupy cavities in the polyoxometalate lattice ordered along b-axis. Water molecules occupy the space left by polyoxometalates, and urea. Polyoxometalate O atoms, the N atoms of urea and O atoms of water molecules are involved in hydrogen bonding. (C) 2001 Elsevier Science B.V. All rights reserved.

Hydrothermal synthesis and crystal structure of a novel layered compound [Ni(C10H8N2)(2)V3O8.5]

A novel layered compound, [Ni(C10H8N2)(2)V3O8.5], was hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. The compound crystallizes in monoclinic system, space group P21/c with a = 1.551 8(3) nm, b = 1.476 1(3) nm, c = 1.048 3(2) nm, beta = 92.02(3), V = 2.399 8(8) nm(3), Z = 4, R = 0. 046 7, wR(2) = 0. 085 9.

Synthesis and crystal structure of a novel compound constructed from tris-(2, 2 '-bipy)ruthenium(II) and decatungstate

Self-assembly of tris-[2,2 ' -bipyridine]ruthenium(II) chloride with decatunstate produced a novel cation radical salt, [Ru(bpy)(3)](2)[W10O32] . 3DMSO. This is the first product of 2,2 ' -bipyridineruthenium(II)-polyoxometalates species. Crystal data: Monoclinic, P2(1)/c, a = 12.902(3) Angstrom, b = 21.487(3) Angstrom, c = 15.854(5) Angstrom, beta = 93.46(2)degrees, V = 4387(2) Angstrom (3), Z = 2, R-1 = 0.0599, wR2 = 0.1183. X-ray crystallographic study showed that the crystal structure was constructed by electyrostatic attraction and C-H . . .O hydrogen bonds between tris-[2,2 ' -bipyridine]ruthenium(II) and decatungstate polyanion. The tris-[2,2 ' -bipyridine]ruthenium molecules occupy cavities in the polyoxometalate lattice ordered along b-axis. (C) 2001 Elsevier Science B.V. All rights reserved.