Layer structure estimation of three-dimensional crystal and two-dimensional molecular film for fluorinated comb copolymers

2008 ◽  
Vol 46 (5) ◽  
pp. 534-546 ◽  
Author(s):  
Atsuhiro Fujimori ◽  
Hiroko Hoshizawa ◽  
Satoshi Kobayashi ◽  
Kaname Kanai ◽  
Yukio Ouchi ◽  
...  
Keyword(s):  
Layer Structure ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Structure Estimation ◽  
Molecular Film ◽  
Dimensional Crystal

scholarly journals Influence of two-dimensional roughness element on boundary layer structure in the favourable pressure gradient region of the swept wing

2019 ◽  
Vol 234 (1) ◽  
pp. 20-27
Author(s):  
Stepan Tolkachev ◽  
Victor Kozlov ◽  
Valeriya Kaprilevskaya
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Layer Structure ◽  
Roughness Element ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Frequency Range ◽  
Swept Wing ◽  
Boundary Layer Structure ◽  
Roughness Elements

In this article, the results of research about stationary and secondary disturbances development behind the localized and two-dimensional roughness elements are presented. It is shown that the two-dimensional roughness element has a destabilizing effect on the disturbances induced by the three-dimensional roughness element lying upstream. In this case, the two-dimensional roughness element causes the appearance of stationary structures, and then secondary perturbations, whose frequency range lies lower than in the case of the stationary vortices excited by a three-dimensional roughness element.

scholarly journals V2O2F4(H2O)2·H2O: a new V4+layer structure related to VOF3

2016 ◽  
Vol 72 (1) ◽  
pp. 80-83 ◽  
Author(s):  
Cameron Black ◽  
Philip Lightfoot
Keyword(s):  
Ionic Liquids ◽  
Title Compound ◽  
Solvothermal Synthesis ◽  
Layer Structure ◽  
Three Dimensional ◽  
Water Molecules ◽  
Frustrated Magnets ◽  
Two Dimensional ◽  
Triangular Lattices ◽  
Solvothermal Conditions

VIVoxyfluorides are of interest as frustrated magnets. The successful synthesis of two-dimensionally connected vanadium(IV) oxyfluoride structures generally requires the use of ionic liquids as solvents. During solvothermal synthesis experiments aimed at producing two- and three-dimensional vanadium(IV) selenites with triangular lattices, the title compound, diaquatetra-μ-fluorido-dioxidodivanadium(IV) monohydrate, V2O2F4(H2O)2·H2O, was discovered and features a new infinite V4+-containing two-dimensional layer comprised of fluorine-bridged corner- and edge-sharing VOF4(H2O) octahedral building units. The synthesis was carried out under solvothermal conditions. The V4+centre exhibits a typical off-centring, with a short V=O bond and an elongatedtrans-V—F bond. Hydrogen-bonded water molecules occur between the layers. The structure is related to previously reported vanadium oxyfluoride structures, in particular, the same layer topology is seen in VOF3.

Two new CdII MOFs of 1,4-bis(1H-benzimidazol-1-yl)butane and flexible dicarboxylate ligands: luminescence sensing towards Fe3+

2020 ◽  
Vol 76 (11) ◽  
pp. 1024-1033
Author(s):  
Fang-Hua Zhao ◽  
Shi-Yao Li ◽  
Wen-Yu Guo ◽  
Zi-Hao Zhao ◽  
Xiao-Wen Guo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Layer Structure ◽  
Three Dimensional ◽  
Supramolecular Network ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy

Two new CdII MOFs, namely, two-dimensional (2D) poly[[[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ2-heptanedioato)cadmium(II)] tetrahydrate], {[Cd(C7H10O4)(C18H18N4)]·4H2O} n or {[Cd(Pim)(bbimb)]·4H2O} n (1), and 2D poly[diaqua[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ4-decanedioato)(μ2-decanedioato)dicadmium(II)], [Cd2(C10H16O4)2(C18H18N4)(H2O)2] n or [Cd(Seb)(bbimb)0.5(H2O)] n (2), have been synthesized hydrothermally based on the 1,4-bis(1H-benzimidazol-1-yl)butane (bbimb) and pimelate (Pim2−, heptanedioate) or sebacate (Seb2−, decanedioate) ligands. Both MOFs were structurally characterized by single-crystal X-ray diffraction. In 1, the CdII centres are connected by bbimb and Pim2− ligands to generate a 2D sql layer structure with an octameric (H2O)8 water cluster. The 2D layers are further connected by O—H...O hydrogen bonds, resulting in a three-dimensional (3D) supramolecular structure. In 2, the CdII centres are coordinated by Seb2− ligands to form binuclear Cd2 units which are linked by bbimb and Seb2− ligands into a 2D hxl layer. The 2D layers are further connected by O—H...O hydrogen bonds, leading to an 8-connected 3D hex supramolecular network. IR and UV–Vis spectroscopy, thermogravimetric analysis and solid-state photoluminescence analysis were carried out on both MOFs. Luminescence sensing experiments reveal that both MOFs have good selective sensing towards Fe3+ in aqueous solution.

Structures of the ZrZn22 family: suprapolyhedral nanoclusters, methods of self-assembly and superstructural ordering

2009 ◽  
Vol 65 (3) ◽  
pp. 300-307 ◽  
Author(s):  
G. D. Ilyushin ◽  
V. A. Blatov
Keyword(s):  
Crystal Structures ◽  
Self Assembly ◽  
Topological Analysis ◽  
Three Dimensional ◽  
Topological Type ◽  
Point Symmetry ◽  
Two Dimensional ◽  
The Matrix ◽  
Nanocluster Precursor ◽  
Dimensional Crystal

A combinatorial topological analysis is carried out by means of the program package TOPOS4.0 [Blatov (2006), IUCr Comput. Commun. Newsl. 7, 4–38] and the matrix self-assembly is modeled for crystal structures of the ZrZn22 family (space group Fd\bar 3m, Pearson code cF184), including the compounds with superstructural ordering. A number of strict rules are proposed to model the crystal structures of intermetallics as a network of cluster precursors. According to these rules the self-assembly of the ZrZn22-like structures was considered within the hierarchical scheme: primary polyhedral cluster → zero-dimensional nanocluster precursor → one-dimensional primary chain → two-dimensional microlayer → three-dimensional microframework (three-dimensional supraprecursor). The suprapolyhedral cluster precursor AB 2 X 37 of diameter ∼ 12 Å and volume ∼ 350 Å3 consists of three polyhedra (one AX 16 of the \bar 43m point symmetry and two regular icosahedra BX 12 of the \bar 3m point symmetry); the packing of the clusters determines the translations in the resulting crystal structure. A novel topological type of the two-dimensional crystal-forming 4,4-coordinated binodal net AB 2, with the Schläfli symbols 3636 and 3366 for nodes A and B, is discovered. It is shown that the ZrZn22 superstructures are formed by substituting some atoms in the cluster precursors. Computer analysis of the CRYSTMET and ICSD databases shows that the cluster AB 2 X 37 occurs in 111 intermetallics belonging to 28 structure types.

scholarly journals EXPOENTE DE AVRAMI PELA EQUAÇÃO DE JMAK PARA MÉTODO NÃO-ISOTÉRMICO DE ANÁLISE TÉRMICA

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Salmo Moreira Sidel ◽  
Elio Idalgo ◽  
Keizo Yukimitu ◽  
João Carlos Silos Moraes ◽  
Fabio Alencar Dos Santos
Keyword(s):  
Crystal Growth ◽  
General Theory ◽  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Nucleation Process ◽  
Vitreous System ◽  
Isothermal Measurements ◽  
Dimensional Crystal

This work reports a discussion about of the general theory for phase transformations of Melh-Johnson-Avrami-Kolmogorov in process involving non-isothermal crystallization. This model allows determine as occurs the mechanism of the nucleus formation and of growth of crystalline phases during the crystallization process. To demonstrate the validity this theory, the Avrami exponent (n) of the LiO2-TeO2-WO3 vitreous system was determined from DSC non-isothermal measurements. The obtained results indicate that the nucleation process is volumetric with two-dimensional or three-dimensional crystal growth. DOI: http://dx.doi.org/10.30609/JETI.2018-2.5566

scholarly journals Crystal structures of tetramethylammonium (2,2′-bipyridine)tetracyanidoferrate(III) trihydrate and poly[[(2,2′-bipyridine-κ2N,N′)di-μ2-cyanido-dicyanido(μ-ethylenediamine)(ethylenediamine-κ2N,N′)cadmium(II)iron(II)] monohydrate]

2016 ◽  
Vol 72 (5) ◽  
pp. 741-746
Author(s):  
Songwuit Chanthee ◽  
Wikorn Punyain ◽  
Supawadee Namuangrak ◽  
Kittipong Chainok
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Layer Structure ◽  
Three Dimensional ◽  
Building Blocks ◽  
Chain Structure ◽  
Water Molecules ◽  
Two Dimensional ◽  
Lattice Water ◽  
Π Stacking

The crystal structures of the building block tetramethylammonium (2,2′-bipyridine-κ2N,N′)tetracyanidoferrate(III) trihydrate, [N(CH3)4][Fe(CN)4(C10H8N2)]·3H2O, (I), and a new two-dimensional cyanide-bridged bimetallic coordination polymer, poly[[(2,2′-bipyridine-κ2N,N′)di-μ2-cyanido-dicyanido(μ-ethylenediamine-κ2N:N′)(ethylenediamine-κ2N,N′)cadmium(II)iron(II)] monohydrate], [CdFe(CN)4(C10H8N2)(C2H8N2)2]·H2O, (II), are reported. In the crystal of (I), pairs of [Fe(2,2′-bipy)(CN)4]−units (2,2′-bipy is 2,2′-bipyridine) are linked together through π–π stacking between the pyridyl rings of the 2,2′-bipy ligands to form a graphite-like structure parallel to theabplane. The three independent water molecules are hydrogen-bonded alternately with each other, forming a ladder chain structure withR44(8) andR66(12) graph-set ring motifs, while the disordered [N(CH3)4]+cations lie above and below the water chains, and the packing is stabilized by weak C—H...O hydrogen bonds. The water chains are further linked with adjacent sheets into a three-dimensional networkviaO—H...O hydrogen bonds involving the lattice water molecules and the N atoms of terminal cyanide groups of the [Fe(2,2′-bipy)(CN)4]−building blocks, forming anR44(12) ring motif. Compound (II) features a two-dimensional {[Fe(2,2′-bipy)(CN)4Cd(en)2]}nlayer structure (en is ethylenediamine) extending parallel to (010) and constructed from {[Fe(2,2′-bipy)(CN)4Cd(en)]}nchains interlinked by bridging en ligands at the Cd atoms. Classical O—H...N and N—H...O hydrogen bonds involving the lattice water molecule and N atoms of terminal cyanide groups and the N—H groups of the en ligands are observed within the layers. The layers are further connectedviaπ–π stacking interactions between adjacent pyridine rings of the 2,2′-bipy ligands, completing a three-dimensional supramolecular structure.

The generation of possible crystal structures of primary amides

1983 ◽  
Vol 388 (1794) ◽  
pp. 133-175 ◽  
Keyword(s):  
Crystal Structures ◽  
Van Der Waals ◽  
Three Dimensional ◽  
Close Packing ◽  
Two Dimensional ◽  
Coulomb Interactions ◽  
Primary Amide ◽  
Size And Shape ◽  
Dimensional Crystal ◽  
Hydrogen Bonded

Procedures are outlined for generation of crystal structures of primary amide molecules by constructing the possible ways in which the molecules may pack. For each given one- or two-dimensional hydrogen-bonded array, ensembles of three-dimensional crystal structures are generated by considering the possible ways in which the arrays may be juxtaposed. Observed and generated hypothetical molecular arrangements are analysed to highlight both favourable and unfavourable features, par­ticularly in terms of close packing principles, the size and shape of the molecule, van der Waals and Coulomb interactions and N-H ∙ ∙ ∙ O bonding geometry.

Cocrystals of 2,6-dichloroaniline and 2,6-dichlorophenol plus three new pseudopolymorphs of their coformers

2015 ◽  
Vol 71 (9) ◽  
pp. 804-813
Author(s):  
Valeska Gerhardt ◽  
Michael Bolte
Keyword(s):  
Crystal Packing ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Network ◽  
Solvent Molecules ◽  
Dimensional Crystal

The structures of cocrystals of 2,6-dichlorophenol with 2,4-diamino-6-methyl-1,3,5-triazine, C6H4Cl2O·C4H7N5, (III), and 2,6-dichloroaniline with 2,6-diaminopyrimidin-4(3H)-one andN,N-dimethylacetamide, C6H5Cl2N·C4H6N4O·C4H9NO, (V), plus three new pseudopolymorphs of their coformers, namely 2,4-diamino-6-methyl-1,3,5-triazine–N,N-dimethylacetamide (1/1), C4H7N5·C4H9NO, (I), 2,4-diamino-6-methyl-1,3,5-triazine–N-methylpyrrolidin-2-one (1/1), C4H7N5·C5H9NO, (II), and 6-aminoisocytosine–N-methylpyrrolidin-2-one (1/1), C4H6N4O·C5H9NO, (IV), are reported. Both 2,6-dichlorophenol and 2,6-dichloroaniline are capable of forming definite synthon motifs, which usually lead to either two- or three-dimensional crystal-packing arrangements. Thus, the two isomorphous pseudopolymorphs of 2,4-diamino-6-methyl-1,3,5-triazine,i.e.(I) and (II), form a three-dimensional network, while theN-methylpyrrolidin-2-one solvate of 6-aminoisocytosine,i.e.(IV), displays two-dimensional layers. On the basis of these results, attempts to cocrystallize 2,6-dichlorophenol with 2,4-diamino-6-methyl-1,3,5-triazine, (III), and 2,6-dichloroaniline with 6-aminoisocytosine, (V), yielded two-dimensional networks, whereby in cocrystal (III) the overall structure is a consequence of the interaction between the two compounds. By comparison, cocrystal–solvate (V) is mainly built by 6-aminoisocytosine forming layers, with 2,6-dichloroaniline and the solvent molecules arranged between the layers.

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