Small-angle X-ray scattering study of the structure of powder fullerene C<Subscript>60</Subscript> and fullerene soot

Powder samples of fullerene C₆₀ and fullerene soot have been studied by the small-angle X-ray scattering method. The radii of gyration of scattering elements have been determined by constructing small-angle diffraction patterns in Guinier coordinates. The data obtained agree well with the results of wide-angle X-ray scattering study, the available data on the structure of the powder fullerene C₆₀ prepared by the Huffman-Krätschmer technique, and the structure of the C₆₀ molecules. Conglomerates of two C₆₀ molecules, along with crystallites ～20 nm in size that are distributed in an amorphous matrix, are present in fullerene powders. Fullerene soot contains C₆₀ crystallites 20–25 nm in size and graphite crystallites ～2–3 nm in size that are distributed in an amorphous matrix.     

Variations in the structure of aromatic solvents under the influence of microadditives of the C<Subscript>60</Subscript> fullerene

The structural ordering of aromatic solvents is investigated using wide-angle X-ray diffraction. It is shown that the degree of structural ordering of aromatic solvents at room temperature decreases in the following sequence: benzene, toluene, and n-xylene. The introduction of the C₆₀ fullerene (～0.001%) into these solvents leads to an increase in the degree of their ordering. Upon introduction of the fullerene, the degree of structural ordering increases significantly in n-xylene and only slightly in toluene and remains virtually unchanged in benzene. An analysis of the small-angle X-ray diffraction patterns of C₆₀ fullerene solutions in benzene likewise demonstrates that the introduction of the fullerene into benzene leads to an insignificant change in the degree of structural ordering of this solvent. The specific features of the structure and behavior of benzene upon interaction with C₆₀ fullerene additives are discussed.     

Mechanisms of the self-organization of star-shaped polymers with a varied structure of branching center based on fullerene C<Subscript>60</Subscript> in solutions

The self-organization of star-shaped polymers in toluene has been studied by small-angle neutron scattering. Polystyrene stars with a mono-C₆₀ branching center are ordered into globular clusters (∼1700 nm in diameter), whereas stars with a double (C₆₀-C₆₀) center are ordered into anisotropic structures (superchains), which are linked (depending on the concentration) into triads (chain clusters ∼2500 nm in diameter). On the contrary, heteroarm polystyrene and poly-2-vinylpyridine stars with a C₆₀ center are weakly associated into dimers. Moderately polar stars with arms composed of polystyrene and diblock copolymer (poly-2-vinylpyridine-poly-tret-butyl methacrylate) form short chains composed of four macromolecules, while stars of higher polarity based on polystyrene and poly-tret-butyl methacrylate form clusters containing ∼12 macromolecules ∼50 nm in diameter. Thus, by varying the structure of the center and the arm polarity, one can control the modes of star structuring.     

Molecular structure of [(C<Subscript>5</Subscript>H<Subscript>5</Subscript>)<Subscript>2</Subscript>(C<Subscript>5</Subscript>H<Subscript>4</Subscript>CH<Subscript>3</Subscript>)(C<Subscript>4</Subscript>H<Subscript>8</Subscript>O)Sm]

The mixed tris-cyclopentadienyl tetrahydrofuranato samarium complex bis-(cyclopentadienyl) methylcyclopentadienyl tetrahydrofuranato samarium (I) was synthesized by reaction of (C₅H₅)₂SmCl with methyl cyclopentadienyl sodium in THF. [(C₅H₅)₂(C₅H₄CH₃)(C₄H₈O)Sm] (I) was characterized by elemental analyses—IR spectra and MS spectra. The structure of [(C₅H₅)₂(C₅H₄CH₃)(C₄H₈O)Sm] (I), which has two slightly different independent molecules per asymmetric unit, has been elucidated through complete X-ray analysis. The crystals are monoclinic, with a = 12.791(3) Å, b = 10.467(2) Å, c = 26.108(5) Å, β = 98.22(2)°, and space group Cc, R = 0.0381 for 2103 observed-reflection with I ≥ 3σ(I).     

Synthesis and structure of fullerene halides C<Subscript>70</Subscript><Emphasis Type="Italic">X</Emphasis><Subscript>10</Subscript> (<Emphasis Type="Italic">X</Emphasis> = Br,Cl) and C<Subscript>78</Subscript>Cl<Subscript>18</Subscript>

The crystal and molecular structures of the fullerene halides C₇₀Br₁₀ · 3C₆H₂Cl₄, C₇₀Cl_8.4Br_1.6, and C₇₈Cl₁₈ have been determined and refined using single-crystal X-ray diffraction with synchrotron radiation. In the molecular structure of C₇₀ X ₁₀ (X = Br, Cl), ten X halogen atoms are located in the equatorial region of the molecule and form one 1,2 and nine 1,4 contacts in C₆ X ₂ hexagons. The structure of the higher fullerene chloride C₇₈Cl₁₈ contains two isomers with symmetry C _2v , which results in the hexagonal symmetry of the crystal due to disordering.     

Analysis of diffuse background on the X-ray diffraction pattern of fullerite C<Subscript>60</Subscript>

Diffuse scattering on the X-ray diffraction pattern of fullerite C₆₀ is analyzed. The characteristics of the short-range order of the amorphous component of fullerite are determined by the Finbak-Warren method. It is established that the short-range order of the amorphous component is similar to the short-range order of lonsdaleite.     

Structure and some properties of [UO<Subscript>2</Subscript>(C<Subscript>5</Subscript>H<Subscript>12</Subscript>N<Subscript>2</Subscript>O)<Subscript>5</Subscript>](ClO<Subscript>4</Subscript>)<Subscript>2</Subscript>

Compound [UO₂(C₅H₁₂N₂O)₅](ClO₄)₂ is synthesized and characterized by thermogravimetry, IR spectroscopy, and X-ray diffraction. The compound crystallizes in the monoclinic crystal system; a = 15.2985(9) Å, b = 26.9676(15) Å, c = 20.6962(11) Å, β = 100.697(1)°, space group P2₁/c, Z = 8, and R = 0.0445. Discrete [UO₂(C₅H₁₂N₂O)₅]²⁺ groups belonging to the AM ₅ ¹ crystal chemical group of uranyl complexes (A = UO ₂ ²⁺ and M ¹=C₅H₁₂N₂O) are uranium-containing structural units of the crystals.     

Synthesis and an X-ray diffraction study of Rb<Subscript>2</Subscript>[(UO<Subscript>2</Subscript>)<Subscript>2</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>3</Subscript>]

The synthesis and X-ray diffraction study of compound Rb₂[(UO₂)₂(C₂O₄)₃], which crystallizes in the monoclinic crystal system, are performed. The unit cell parameters are as follows: a = 7.9996(6) Å, b = 8.8259(8) Å, c = 11.3220(7) Å, β = 105.394(2)°, and V = 770.7(1) ų; space group P2₁/n, Z = 2, and R ₁ = 0.0271. [(UO₂)₂(C₂O₄)₃]^2? layers belonging to the AK _0.5 ⁰² T ¹¹ crystal chemical group of uranyl complexes (A = UO ₂ ²⁺ , K ⁰² = C₂O ₄ ^2? , and T ¹¹ = C₂O ₄ ^2? ) are uranium-containing structural units of the crystals. The layers are connected with outer-sphere rubidium cations by electrostatic interactions.     

X-Ray Crystal Structure of <Emphasis Type="Italic">trans</Emphasis>-PdCl<Subscript>2</Subscript>(PPh<Subscript>2</Subscript>C<Subscript>12</Subscript>H<Subscript>7</Subscript>S<Subscript>3</Subscript>)<Subscript>2</Subscript>, a New Morphology

Herein we report the crystal structure of trans-PdCl₂(PPh₂C₁₂H₇S₃)₂, 1, in a different morphology than has previously been reported [Stott et al. (Dalton Trans (4):652–653, 2005]. This structure crystallizes in a P-1 space group with a = 9.4249(19) Å, b = 11.540(2) Å, c = 12.559(3) Å, α = 79.07(3)°, β = 78.04(3)°, γ = 69.44(3)°, Z = 1. The earlier structure possessed a P2₁/n space group. Additionally the terthienyl moieties of 1 demonstrate the anti orientation exclusively while the P2₁/n space group structure has some syn and even syn/anti mixed geometries included.     

Polyamorphous transition in amorphous fullerites C<Subscript>70</Subscript>

Samples of amorphous fullerites C₇₀ have been obtained by mechanical activation (grinding in a ball mill). The structure of the samples has been investigated by neutron and X-ray diffraction. The high-temperature (up to 1200°C) annealing of amorphous fullerites revealed a polyamorphous transition from molecular to atomic glass, which is accompanied by the disappearance of fullerene halos at small scattering angles. Possible structural versions of the high-temperature amorphous phase are discussed.     

Stimulated Raman scattering by C<Subscript>12</Subscript>H<Subscript>22</Subscript>O<Subscript>11</Subscript> sugar (sucrose)

The efficient Stokes and anti-Stokes laser emissions with Raman frequency shift at about 2960 cm^?1 are excited in a food C₁₂H₂₂O₁₁ sugar (sucrose) single crystal under pulsed pumping. Other (χ⁽²⁾ + χ⁽³⁾) effects of the parametric Raman generation are also detected.     

Crystal Structure and IR Study of (C<Subscript>6</Subscript>H<Subscript>5</Subscript>NH<Subscript>3</Subscript>)[ZnCl(HPO<Subscript>3</Subscript>)]

Abstract  

A new hybrid phosphate, (C₆H₅NH₃)[ZnCl(HPO₃)], has been synthesized and its structure characterized from single-crystal X-ray diffraction. The title compound crystallizes in the orthorhombic space group Pbca (n. 61) with the unit-cell parameters: a = 9.8635(2) ?, b = 9.4516(10) ?, c = 22.2430(4) ?, Z = 8 and V = 2,073.62(6) ?³. The final R factors were R/ωR = 0.0361/0.0924. Its framework might be described as a layered structure with two (010)-parallel cationic and anionic layers. The IR spectrum of this phase shows characteristic bands of phosphite and anilinium groups.     

Synthesis and crystal structure of the [Co<Subscript>2</Subscript>(Nicotinamide)<Subscript>4</Subscript>(C<Subscript>4</Subscript>H<Subscript>9</Subscript>COO)<Subscript>4</Subscript>(H<Subscript>2</Subscript>O)] complex

The [Co₂ L ₄(C₄H₉COO)₄(H₂O)] coordination compound of cobalt(II) valerate with nicotinamide (L) is synthesized and studied by IR spectroscopy. The crystal structure of the synthesized compound is determined. The crystals are triclinic, and the unit cell parameters are as follows: a = 10.2759(10) Å, b = 16.3858(10) Å, c = 16.4262(10) Å, α = 100.538(10)°, β = 101.199(10)°, γ = 90.813 (10)°, Z = 2, and space group P \(\bar 1\). The structural units of the crystal are dimeric molecular complexes in which pairs of cobalt atoms are linked by triple bridges formed by oxygen atoms of two bidentately coordinated valerate anions and a water molecule. The octahedral coordination of each cobalt atom is complemented by the pyridine nitrogen atoms of two nicotinamide ligands and the oxygen atom of the monodentate valerate group. The hydrocarbon chains of the valerate anions are disordered over two or three positions each.     

Intermolecular interactions involved in the crystal structure of 2-amino-5-methylpyridinium hexabromostannate (IV), (C<Subscript>6</Subscript>H<Subscript>9</Subscript>N<Subscript>2</Subscript>)<Subscript>2</Subscript>[SnBr<Subscript>6</Subscript>]

The salt bis(2-amino-5-methylpyridinium) hexabromostannate(IV) (C₆H₉N₂)₂[SnBr₆] is monoclinic, P2 ₁ /c, with the following cell parameters: a=9.1636(18) ?, b=28.767(7) ?, c=16.956(17) ?, β=101.008(5)°, V=4387.5(17) ?³, Z=8, formula units. X-ray crystallography revealed that the structure can be regarded as a semi-regular three-dimensional array of anions, with pairs of cations forming layers perpendicular to b axis in the cavities between the anions. The cohesion forces that connects molecules in the organic layers are hydrophilic N⋯HCH₂ and HN⋯HN hydrogen bonding as well as hydrophobic π-π stacking and CH₃⋯π interactions. Cations and anions are connected via strong Br⋯H hydrogen bonding. Supplementary material CCDC 276493 contains the supplementary crystallographic data. These data can be obtained free of charge via www.ccdc. cam.ac.uk/data_request/cif, by e-mailing data_ request@ccdc.cam.ac.uk, or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44(0)1223-336033.     

Crystal structure of the new radical cation salt (<Emphasis Type="Italic">DOET</Emphasis>)<Subscript>4</Subscript>[Fe(CN)<Subscript>5</Subscript>NO]<Subscript>1.25</Subscript>(C<Subscript>6</Subscript>H<Subscript>5</Subscript>Cl)<Subscript>0.75</Subscript>

A new radical cation salt based on 4,5-(1,4-dioxanediyl-2,3-dithio)-4′,5′-ethylenedithiotetrathiafulvalene (DOET) with the photochromic anion [Fe(CN)₅NO]^2?, namely, (DOET)₄[Fe(CN)₅ NO]_1.25(C₆H₅Cl)_0.75, is synthesized. Single crystals of this salt are studied using X-ray diffraction [a = 10.398(2) Å, b = 11.168(2) Å, c = 18.499(4) Å, α = 103.14(3)°, β = 92.80(3)°, γ = 106.02(3)°, V = 1996.3(7) ų, space group \(P\bar 1\), and Z = 1]. In the structure, radical cation layers alternate with anion layers along the c axis. The centrosymmetric dimers are formed by DOET radical cations in the donor layer with packing of the β type. Like the vast majority of DOET-based salts, the new salt possesses semiconductor properties.     

Synthesis and Structure of Bis(3-dimethylammonium-1-propyne)pentachlorobismuthate(III) (C<Subscript>5</Subscript>H<Subscript>10</Subscript>N)<Subscript>2</Subscript>BiCl<Subscript>5</Subscript>

Abstract  

The synthesis and crystal structure are given for the bis(3-dimethylammonium-1-propyne)pentachlorobismuthate(III) salt. An X-ray investigation has shown that the title compound crystallizes at 298 K in a centrosymmetric monoclinic system, space group C2/c with the following lattice parameters a = 12.6215(4) ?, b = 18.9228(5) ?, c = 8.3134(2) ?, β = 104.100(2)°, V = 1925.70(9) ?³. The structure was solved from 7,716 independent reflections with R ₁ = 0.0457 and wR ₂ = 0.0906, and refined with 85 parameters. The structure consists of disordered 3-dimethylammonium-1-propyne, C₅H₉NH⁺ cations and polynuclear anions in which slightly distorted (BiCl₅)²⁻ anions, sharing an apex are interconnected in chains. These chains are themselves interconnected by means of N–H···Cl originating from the C₅H₉NH⁺ entities, forming a three-dimensional network.     

[Cd<Subscript>5</Subscript>(OH)(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>][CH<Subscript>3</Subscript>CO<Subscript>2</Subscript>]<Subscript>9</Subscript>, a cadmium hydroxy-acetate compound with a layered network

[Cd₅(OH)(H₂O)₃][CH₃CO₂]₉ crystallizes in the triclinic system, with the space group P , a = 10.897(3) Å, b = 11.035(5) Å, c = 16.061(12) Å, = 96.83(7), = 95.31(8), = 118.22(6) and z = 2. Its structure has been determined using 9497 unique single crystal data. The final refinements let the agreement factors R₁ and wR₂(F²) converge to reach the respective values of 0.0548 and 0.0986. R₁ = 0.0338 for the 7264 unique data with I > 2(I). [Cd₅(OH)(H₂O)₃][CH₃CO₂]₉ is a cadmium hydroxide acetate compound with a bi-dimensional structure in which hydrogen bonds insure cohesion between layers stacked along the [1 10] direction. The inorganic network is built up of layers constituted of CdO₆ octahedra and CdO₇ pentagonal bi-pyramids sharing edge or corner.     

Refinement of the crystal structure of rhombohedral KU<Subscript>2</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript> as a representative of orthophosphates with the NaZr<Subscript>2</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript> structure

The crystal structure of the high-temperature β modification of synthetic orthophosphate KU₂(PO₄)₃ was refined from powder X-ray diffraction data by the Rietveld method: sp. gr. \(R\bar 3c\), the unit-cell parameters a= 9.113(1) Å and c= 24.997(1) Å. The isotropic refinement converged to R _wp = 6.15, R _B = 2.14, R _F = 3.52, and S = 0.42. It was confirmed that β-KU₂(PO₄)₃ belongs to the structure type of sodium zirconium phosphate containing an actinide atom in a sixfold (octahedral) coordination formed by oxygen atoms, which is unusual for orthophosphates. The principal interatomic distances and bond angles in the structure are reported.     

Synthesis and crystal structure of bis(malonato)tetra (aqua)barium(II)cobalt(II): [BaCo(C<Subscript>3</Subscript>H<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>4</Subscript>]

The title compound [BaCo(C₃H₂O₄)₂(H₂O)₄] was synthesized and its crystal structure was determined. The compound is orthorhombic, space group Pccn with a = 18.974(3) Å, b = 6.783(2) Å, c = 9.394(4) Å. The structure is polymeric and consists of edge-sharing BaO₈ polyhedra and CoO₆ octahedra linked together by the malonate groups. The geometry around the Ba(II) centres is a slightly distorted square-antiprism with Ba–O distances ranging from 2.789(4) to 2.843(4) Å. Around the Co(II) centres, the coordination forms a distorted octahedron with Co–O bonds between 2.040(3) and 2.238(4) Å.     

Synthesis and Structure of Ba<Subscript>5</Subscript>(V<Subscript>2</Subscript>O<Subscript>7</Subscript>)<Subscript>2</Subscript>Cl<Subscript>2</Subscript>

Abstract  A new barium chlorovanadate, Ba₅(V₂O₇)₂Cl₂, was isolated by a high-temperature (850 °C) reaction employing a CsCl/RbCl flux. The structure was determined by single crystal X-ray diffraction methods. This compound crystallizes in an orthorhombic crystal system, Pmmn (No. 59), with a = 11.558(2) ?, b = 15.164(3) ?, c = 10.023(2) ?, Z = 4 and V = 1756.7(6) ?³. The structure of Ba₅(V₂O₇)₂Cl₂ was determined by full-matrix, least-squares methods with R ₁ = 0.0398, wR ₂ = 0.1069 and GOF = 1.048 for all data. This new structure can be described as a composite lattice made up of mixed covalent and ionic moities. The extended framework is orchestrated by stacked [Ba(V₂O₇)Cl]³⁻ slabs that are interconnected by Ba²⁺ cations through Ba–O bonds to the [V₂O₇] units. The Ba²⁺ and Cl^- ions form BN-type “[BaCl]” sheets with pseudo-hexagonal windows that are centered by [V₂O₇]⁴⁻ pyrovanadate units. Graphical Abstract  The structure of a new chlorovanadate, Ba₅(V₂O₇)₂Cl₂, exhibits an interesting BN-type salt lattice that consists of an extended [BaCl] sheet containing pseudo-hexagonal windows that are centered by [V₂O₇] pyrovanadate units.