Two Cd-MOFs with different types of channels based on phenylimidazole dicarboxylic acids: Synthesis, crystal structure and solid fluorescence properties

2021 ◽  
pp. 131874
Author(s):  
Yuxuan Jiang ◽  
Jianping Dong ◽  
Fugang Sun ◽  
Ruixue Li ◽  
Huilu Wu
Keyword(s):  
Crystal Structure ◽  
Dicarboxylic Acids ◽  
Fluorescence Properties ◽  
Different Types ◽  
Solid Fluorescence

Crystal structure images of large gold clusters and growing crystals by HRTEM

1984 ◽  
Vol 42 ◽  
pp. 428-429
Author(s):  
L.R. Wallenberg ◽  
J.-O. Bovin ◽  
G. Schmid
Keyword(s):  
Crystal Structure ◽  
Nucleation And Growth ◽  
Close Packing ◽  
Gold Clusters ◽  
Molecular Weight Determination ◽  
Growth Mechanisms ◽  
Starting Point ◽  
Different Types ◽  
Nucleation And Growth Mechanisms ◽  
Points Of View

Metallic clusters are interesting from various points of view, e.g. as a mean of spreading expensive catalysts on a support, or following heterogeneous and homogeneous catalytic events. It is also possible to study nucleation and growth mechanisms for crystals with the cluster as known starting point.Gold-clusters containing 55 atoms were manufactured by reducing (C6H5)3PAuCl with B2H6 in benzene. The chemical composition was found to be Au9.2[P(C6H5)3]2Cl. Molecular-weight determination by means of an ultracentrifuge gave the formula Au55[P(C6H5)3]Cl6 A model was proposed from Mössbauer spectra by Schmid et al. with cubic close-packing of the 55 gold atoms in a cubeoctahedron as shown in Fig 1. The cluster is almost completely isolated from the surroundings by the twelve triphenylphosphane groups situated in each corner, and the chlorine atoms on the centre of the 3x3 square surfaces. This gives four groups of gold atoms, depending on the different types of surrounding.

Crystal structure and fluorescence properties of the supramolecule complex [Dy(H2L)(HL)(H2O)3]·0.5dipy·2H2O

2006 ◽  
Vol 59 (16) ◽  
pp. 1785-1791 ◽  
Author(s):  
Wang-Ting Wu ◽  
Shui-Yang He ◽  
Huai-Ming Hu ◽  
Meng-Lin Yang ◽  
Yao-Yu Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fluorescence Properties

2. Symmetry

2016 ◽  
pp. 24-38
Author(s):  
A. M. Glazer
Keyword(s):  
Crystal Structure ◽  
Reflection Point ◽  
Notation System ◽  
Space Group ◽  
Space Groups ◽  
Different Types ◽  
Point Groups

In order to explain what crystals are and how their structures are described, we need to understand the role of symmetry, for this lies at the heart of crystallography. ‘Symmetry’ explains the different types of symmetry: rotational, mirror or reflection, point, chiral, and translation. There are thirty-two point groups and seven crystal systems, according to which symmetries are present. These are triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic. Miller indices, lattices, crystal structure, and space groups are described in more detail. Any normal crystal belongs to one of the 230 space group types. Crystallographers generally use the International Notation system to denote these space groups.

The Transition Metal-rich Orthophosphate Arrojadite with Special Structural Features

2010 ◽  
Vol 65 (12) ◽  
pp. 1427-1433 ◽  
Author(s):  
Christoph Kallfaß ◽  
Constantin Hoch ◽  
Hermann Schier ◽  
Arndt Simon ◽  
Helmut Schuber
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Single Crystal ◽  
Structural Features ◽  
Nickel Plate ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Different Types ◽  
New Feature

The crystal structure of the transition metal-rich orthophosphate mineral arrojadite was reexamined, and the disorder phenomena were analyzed applying modern X-ray single-crystal diffraction and refinement methods on samples from Nickel Plate (USA) and Hagendorf (Germany). As a new feature of the arrojadite structure, two different types of channels oriented along [010] are described. The occupancy of the atomic positions inside these channels have been elucidated.

Crystal Structure Control of ZnxCd1−xS Alloyed Nanocrystals and Structural Dependent Fluorescence Properties

NANO ◽  
2019 ◽  
Vol 14 (08) ◽  
pp. 1950098
Author(s):  
Kaili Qin ◽  
Jingling Li ◽  
Yanqing Zhu ◽  
Xueqing Xu ◽  
Xiudi Xiao ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Phase ◽  
Fluorescence Properties ◽  
Pure Zinc ◽  
Structure Control ◽  
Zinc Blende ◽  
Coating Method ◽  
Ratio Condition ◽  
One Step ◽  
Zinc Blende Structure

Crystal structure control is so important to the fluorescence properties that each element should be considered carefully. In conventional synthesis of ZnxCd[Formula: see text]S alloyed nanocrystals (NCs), most of studies focus on ligand–surface interaction on the formation of either zinc blende or wurtzite ZnxCd[Formula: see text]S nanocrystals, instead of the reactant source. In this work, mixed crystal phase was found easily in ZnxCd[Formula: see text]S alloyed NCs when reaction proceeded at high Zn/Cd source ratio condition. Therefore, we regulate the Zn/Cd ratio to obtain relative pure zinc-blende structure, and study the influence of structure change on the fluorescence properties. Further, we have proposed a two-step ZnS coating method to acquire ZnxCd[Formula: see text]S/ZnS NCs with separated crystal-phase between core and shell. Compared with maximum QY of 81% for ZnxCd[Formula: see text]S/ZnS NCs synthesized by conventional one-step coating method, the performance of the optimized NCs has significantly improved with maximum QY of 93%.

scholarly journals Polycystic kidney disease-like domains of clostridial collagenases and their role in collagen recruitment

2011 ◽  
Vol 392 (11) ◽  
Author(s):  
Ulrich Eckhard ◽  
Hans Brandstetter
Keyword(s):  
Crystal Structure ◽  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Polycystic Kidney ◽  
Domain Organization ◽  
Clostridium Histolyticum ◽  
Different Types ◽  
Catalytic Zinc

AbstractBacterial collagenases exhibit a multimodular domain organization. While the N-terminal collagenase unit harbors the catalytic zinc and suffices to degrade peptidic substrates, collagen substrates come in different types, explaining the requirement for accessory domains such as polycystic kidney disease (PKD)-like domains for efficient catalysis. How the recognition and unfolding of (micro-)fibrillar or triple-helical collagen is accomplished are only poorly understood. Here, we present the crystal structure of the PKD-like domain of collagenase G fromClostridium histolyticum.The β-barrel structure reveals a two-tier architecture, connected by kinked hinge segments. Together with sheet extension as a generic oligomerization mechanism, this explains the cooperativity among accessory domains as well as their adaptivity to varying substrates.

Methyl 5-phenyl-1H-pyrazole-3-carboxylate

2007 ◽  
Vol 63 (11) ◽  
pp. o4474-o4474 ◽  
Author(s):  
Guanghua Zhou ◽  
Yue An ◽  
Jing Han ◽  
Maofa Ge ◽  
Yongheng Xing
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Title Compound ◽  
Phenyl Ring ◽  
Pyrazole Ring ◽  
Compound C ◽  
Centroid Distance ◽  
Different Types ◽  
Neighboring Molecule

The title compound, C11H10N2O2, was prepared by the esterfication of 5-phenyl-1H-pyrazole-3-carboxylic acid with methanol. The phenyl ring is rotated out of the pyrazole plane, forming a dihedral angle of 6.4 (1)°. The crystal structure is stabilized by intermolecular aromatic π–π interactions [with a centroid–centroid distance of 3.862 (3) Å between the pyrazole ring and the benzene ring of a neighboring molecule], and by three different types of hydrogen bond (N—H...N, N—H...O and C—H...O).

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