Elucidation of the two-dimensional structure of an α-amino acid surfactant monolayer on water using synchrotron X-ray diffraction

Nature ◽  
1987 ◽  
Vol 328 (6125) ◽  
pp. 63-66 ◽  
Author(s):  
Sharon Grayer Wolf ◽  
Leslie Leiserowitz ◽  
Meir Lahav ◽  
Moshe Deutsch ◽  
Kristian Kjaer ◽  
...  
1965 ◽  
Vol 9 ◽  
pp. 142-151 ◽  
Author(s):  
R. L. Prickett ◽  
R. L. Hough

AbstractSilicon carbide vvas generated by pyrolysis of gas mixtures consisting of silicon tetrachloride, hydrogen, and organic vapors, such as acetone, on fine tungsten wires resistance-heated at 1500°C. Prominent two-dimensional structure was demonstrated for the 220 reflection. All other lines were of the normal threedimensional lattice type.Elevation of less than 100° in the pyrolysis temperature eliminated the twodimensional reflection, and simultaneously changed the visible crystallite size.Specialized techniques were used td generate the silicon carbide deposits and also to examine the structure of these deposits by X-ray diffraction to obtain lines from only the silicon carbide while ignoring the tungsten wire core. Diffraction techniques include offset collimation and vertical integration.


1991 ◽  
Vol 237 ◽  
Author(s):  
P. Fenter ◽  
Jun Li ◽  
p. Eisenberger ◽  
T. A. Ramanarayanan ◽  
K. S. Liang

ABSTRACTWe describe the two dimensional structure of n-Alkyl Thiols, CH3(CH217SH(C18, self-assembled on the surfaces of Au(111) and Ag(111). By using Grazing Incidence X-ray Diffraction (GIXD), we show that C18 forms ordered and dense monolayers. Although the properties of Au and Ag are very similar (for instance, the lattice constants of Au an Ag are nearly identical), the structure of C18on these two substrates is very different.


2018 ◽  
Vol 74 (12) ◽  
pp. 1576-1580 ◽  
Author(s):  
Ning-Ning Chen ◽  
Jian-Ning Ni ◽  
Jun Wang

A novel two-dimensional CdII coordination framework, poly[[[μ-1,3-bis(2-methyl-1H-imidazol-1-yl)benzene-κ2 N:N′](μ-1,3-phenylenediacetato-κ4 O,O′:O′′,O′′′)cadmium(II)] dihydrate], {[Cd(C10H8O4)(C14H14N4)]·2H2O} n or {[Cd(PDA)(1,3-BMIB)]·2H2O} n [1,3-BMIB is 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene and H2PDA is 1,3-phenylenediacetic acid], has been prepared and characterized using IR, elemental analysis, thermal analysis and single-crystal X-ray diffraction, the latter revealing that the compound is a (4,4) grid coordination polymer with layers oriented parallel to the bc crystal planes. In the crystal, adjacent layers are further connected by O—H...O and C—H...O hydrogen bonds, forming a three-dimensional structure in the solid state. In addition, the compound exhibits strong fluorescence emissions and shows photocatalytic activity for the degradation of methylene blue in the solid state at room temperature.


2019 ◽  
Vol 75 (2) ◽  
pp. 196-199 ◽  
Author(s):  
Ning-Ning Chen ◽  
Jian-Ning Ni ◽  
Jun Wang ◽  
Jian-Qing Tao

A novel two-dimensional (2D) ZnII coordination framework, poly[[μ-1,3-bis(2-methyl-1H-imidazol-1-yl)benzene](μ-5-nitrobenzene-1,3-dicarboxylato)zinc(II)], [Zn(C8H3NO6)(C14H14N4)] n or [Zn(NO2-BDC)(1,3-BMIB)] n [1,3-BMIB is 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene and NO2-H2BDC is 5-nitrobenzene-1,3-dicarboxylic acid], has been prepared and characterized by IR, elemental analysis, thermal analysis and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis revealed that the compound is a new 2D polymer with a 63 topology parallel to the (10\overline{2}) crystal planes based on left-handed helices, right-handed helical NO2-BDC–Zn chains and [Zn2(1,3-BMIB)2] n clusters. In the crystal, adjacent layers are further connected by C—H...O hydrogen bonds, C—H...π interactions, C—O...π interactions and N—O...π interactions to form a three-dimensional structure in the solid state. In addition, the compound exhibits strong fluorescence emissions in the solid state at room temperature.


Author(s):  
K. H. Downing ◽  
S. G. Wolf ◽  
E. Nogales

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.


1998 ◽  
Vol 63 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Miloš Tichý ◽  
Luděk Ridvan ◽  
Miloš Buděšínský ◽  
Jiří Závada ◽  
Jaroslav Podlaha ◽  
...  

The axially chiral bis(α-amino acid)s cis-2 and trans-2 as possible building blocks for polymeric structures of novel type of helicity were prepared. Their configuration has been determined by NMR spectroscopy and, in the case of the trans-isomer, confirmed by single-crystal X-ray diffraction. Analogous pair of stereoisomeric diacids cis-3 and trans-3, devoid of the amino groups, was also prepared and their configuration assigned. The observed differences in the NMR spectra of cis- and trans-isomers of 2 and 3 are discussed from the viewpoint of their different symmetry properties.


2008 ◽  
Vol 73 (1) ◽  
pp. 24-31
Author(s):  
Dayu Wu ◽  
Genhua Wu ◽  
Wei Huang ◽  
Zhuqing Wang

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Runmei Ding ◽  
Zixin He ◽  
Meilin Wang ◽  
Danian Tian ◽  
Peipei Cen

AbstractBased on 2-(4-pyridyl)-terephthalate (H2pta) and oxalate ligands, two new lanthanide-containing coordination polymers (CPs), [Tb(pta)(C2O4)0.5(H2O)2)]·2H2O (1) and [Sm(pta)(C2O4)0.5(H2O)2)]·2H2O (2), have been synthesized under solvothermal conditions. The structures of both 1 and 2 have been determined by single-crystal X-ray diffraction. Infrared, elemental analysis, powder X-ray diffraction and thermogravimetric analysis data are also presented. The crystals of 1 and 2 exhibit isostructural layer-like networks, crystallizing in the triclinic space group P$‾{1}$. The layers are further stabilized and associated into 3D architectures through hydrogen bonding. Remarkably, the CPs 1 and 2 exhibit excellent water stability and remarkable thermostability with thermal decomposition temperatures of more than 420 °C.


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