Inclusion of cyclodextrins in a metallosupramolecular framework via structural transformations

CrystEngComm ◽  
2021 ◽  
Author(s):  
Supattra Somsri ◽  
Naoto Kuwamura ◽  
Tatsuhiro Kojima ◽  
Nobuto Yoshinari ◽  
Apinpus Rujiwatra ◽  
...  
Keyword(s):  
Structural Transformation ◽  
Structural Transformations ◽  
Porous Framework ◽  
Site Selective ◽  
Complex Anions

A 3D porous framework composed of D-penicillaminato AuI3CoIII2 complex anions and aqua sodium(I) cations underwent a solvent-mediated structural transformation to generate a multilayer framework, including α-CD as cyclic trimers. Site-selective...

A two-dimensional porous framework: solvent-induced structural transformation and selective adsorption towards malachite green

2017 ◽  
Vol 46 (26) ◽  
pp. 8350-8353 ◽  
Author(s):  
Huanzhi Li ◽  
Xueting Fang ◽  
Sha Ma ◽  
Yanfei Niu ◽  
Xiaoli Zhao ◽  
...  
Keyword(s):  
Malachite Green ◽  
Structural Transformation ◽  
Selective Adsorption ◽  
Structural Transformations ◽  
Two Dimensional ◽  
Porous Framework

A two-dimensional porous framework SHU-1 could undergo solvent-induced structural transformations to SHU-1a in methanol and SHU-1b in water. SHU-1, SHU-1a and SHU-1b showed selective adsorption towards malachite green.

Structural Transformation of a Germanium Σ=13 (510) [001] Tilt Grain Boundary under the Electron Beam

1990 ◽  
Vol 48 (1) ◽  
pp. 52-53 ◽  
Author(s):  
Jean-Luc Rouvière ◽  
Alain Bourret
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Structural Transformation ◽  
Mirror Symmetry ◽  
High Resolution Electron Microscopy ◽  
Structural Transformations ◽  
Covalent Bonds ◽  
Resolution Electron ◽  
Tilt Grain Boundary

The possible structural transformations during the sample preparations and the sample observations are important issues in electron microscopy. Several publications of High Resolution Electron Microscopy (HREM) have reported that structural transformations and evaporation of the thin parts of a specimen could happen in the microscope. Diffusion and preferential etchings could also occur during the sample preparation.Here we report a structural transformation of a germanium Σ=13 (510) [001] tilt grain boundary that occurred in a medium-voltage electron microscopy (JEOL 400KV).Among the different (001) tilt grain boundaries whose atomic structures were entirely determined by High Resolution Electron Microscopy (Σ = 5(310), Σ = 13 (320), Σ = 13 (510), Σ = 65 (1130), Σ = 25 (710) and Σ = 41 (910), the Σ = 13 (510) interface is the most interesting. It exhibits two kinds of structures. One of them, the M-structure, has tetracoordinated covalent bonds and is periodic (fig. 1). The other, the U-structure, is also tetracoordinated but is not strictly periodic (fig. 2). It is composed of a periodically repeated constant part that separates variable cores where some atoms can have several stable positions. The M-structure has a mirror glide symmetry. At Scherzer defocus, its HREM images have characteristic groups of three big white dots that are distributed on alternatively facing right and left arcs (fig. 1). The (001) projection of the U-structure has an apparent mirror symmetry, the portions of good coincidence zones (“perfect crystal structure”) regularly separate the variable cores regions (fig. 2).

The Eventfulness of Social Reproduction

2011 ◽  
Vol 29 (4) ◽  
pp. 294-314 ◽  
Author(s):  
Adam Moore
Keyword(s):  
Structural Transformation ◽  
Social Reproduction ◽  
Social Life ◽  
Structural Transformations ◽  
Social Structures ◽  
Stability And Change ◽  
Theoretical Assumptions

The work of William Sewell and Marshall Sahlins has led to a growing interest in recent years in events as a category of analysis and their role in the transformation of social structures. I argue that tying events solely to instances of significant structural transformation entails problematic theoretical assumptions about stability and change and produces a circumscribed field of events, undercutting the goal of developing an “eventful” account of social life. Social continuity is a state that is achieved just as much as are structural transformations, and events may be constitutive of processes of reproduction as well as change.

Physical Analysis of Structural Transformation in Ge-Incorporated a-SbxSe100-x System

2011 ◽  
Vol 316-317 ◽  
pp. 45-53 ◽  
Author(s):  
Sunanda Sharda ◽  
Neha Sharma ◽  
Pankaj Sharma ◽  
Vineet Sharma
Keyword(s):  
Structural Transformation ◽  
Chalcogenide Glasses ◽  
Theoretical Study ◽  
Far Infrared ◽  
Structural Transformations ◽  
Physical Parameters ◽  
Physical Analysis ◽  
Melt Quenching ◽  
Structural Environment ◽  
Rigidity Percolation

Chalcogenide glasses are suitable for far-infrared and imaging applications. In the present study, Sb10Se90-xGex (x=0, 19, 21, 23, 25, 27) system has been chosen to study structural transformations via physical parameters. Bulk samples with x = 0, 19, 21, 23, 25 and 27 have been prepared using the melt-quenching technique. A theoretical study of the ternary glass system revealed that there was a significant change in the structural environment of the system due to rigidity percolation, which took place as Se was replaced by Ge, and hence resulted in changes in other physical parameters of the system.

Multiple structural transformations coupled with switchable magnetic and dielectric responses in an amphidynamic crystal of 4′-tert-butylbenzylpyridinium bis(maleonitriledithiolate)nickelate

2015 ◽  
Vol 3 (30) ◽  
pp. 7906-7915 ◽  
Author(s):  
Wei-Hua Ning ◽  
Lu Zhai ◽  
Jian-Lan Liu ◽  
Xiao-Ming Ren ◽  
Katsuya Ichihashi ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Structural Transformation ◽  
Magnetic Phase ◽  
Structural Transformations ◽  
Magnetic Phase Transitions

An amphidynamic crystal shows a two-step structural transformation; the steps are coupled to both hysteretic magnetic phase transitions and dielectric anomalies.

Clay Structural Transformations during Firing

2010 ◽  
Vol 68 ◽  
pp. 31-37 ◽  
Author(s):  
Philippe Blanchart ◽  
Sarah Deniel ◽  
Nicolas Tessier-Doyen
Keyword(s):  
High Temperature ◽  
Structural Transformation ◽  
Structural Characteristics ◽  
Structural Transformations ◽  
Complex Relationship ◽  
Minor Elements ◽  
Composite Microstructure ◽  
And Behavior ◽  
High Temperature Form ◽  
Mineral Type

Silicate ceramics with clays are some of the most complicated ceramic systems because of the very complex relationship between the behavior of mineral materials during the ceramic processing and the transformations during heating. A major challenge is to predict the phase transformations in silicate ceramics, since complex relationship occur between the microstructural and structural characteristics of fired product and the physical properties. Clay minerals undergo strong structural transformations during heating, simultaneously to a complex path of thermal transformations. Individual reactions cannot simply identify since they are closely related and overlapped. At temperature above 800°C, new phases are recrystallized and many of the reactions are strongly topotactic. Mullite is the most important phase, which recrystallizes with a range of morphology and stoichiometry. Variables affecting the mullite formation include the clay mineral type and behavior during heating, the possible occurrence of liquid and impurities as Fe. It results in large variations of the stoichiometry and shape of mullite crystals, which are embedded in a low ordered phase to form a micro-composite microstructure. This presentation will review recent research, looking at structural transformations in some typically used phyllosilicate systems : (i) structural transformation of kaolinite and mica phases were identified at temperature up to 1100°C. They evidence a residual structural order of high temperature phases which is favorable to the topotactic recrystallization of mullite; (ii) from the high temperature form of phyllosilicates, an organized network of mullite can be obtained; (iii) the composition of a local and transient liquid and the presence of minor elements as Fe has a significant influence on the mullite morphology; (iv) mechanical properties are closely related to size and organization degree of the mullite network; (v) the process itself influence the kinetic of structural transformation and particularly the powder compact density and the thermal cycle. These research in silicate ceramics evidence multiple and complex challenges, providing opportunities for future development.

New hybrid organic-zincophosphate frameworks: single-crystal-to-single-crystal structural transformation and remarkable thermal and chemical stabilities

2016 ◽  
Vol 45 (17) ◽  
pp. 7231-7234 ◽  
Author(s):  
Tsung-Yuan Chang ◽  
Zhao-Nan Yan ◽  
Chun-Chi Wang ◽  
Hsing-Chun Li ◽  
Hsiu-Mei Lin ◽  
...  
Keyword(s):  
Single Crystal ◽  
Structural Transformation ◽  
Structural Transformations ◽  
Metal Phosphates ◽  
Crystal Structural

This research is the first example of hybrid metal phosphates that undergo SCSC structural transformations and exhibit remarkable thermal and chemical stabilities.

scholarly journals Hydrogen-Bonding Assembly of Coordination Polymers Showing Reversible Dynamic Solid-State Structural Transformations

Inorganics ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 115
Author(s):  
Hitoshi Kumagai ◽  
Sadahiro Yagishita ◽  
Ken Kanazashi ◽  
Mariko Ishii ◽  
Shinya Hayami ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Structural Transformation ◽  
Coordination Polymers ◽  
Chain Structure ◽  
Structural Transformations ◽  
The Other ◽  
Ambient Conditions ◽  
Thermally Induced ◽  
Dehydration Processes

We herein report the synthesis, single-crystal structures of coordination polymers, and structural transformations of complexes employing 1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile (tdpd2−) and pyrazine (pyz) as bridging ligands. {[M(H2O)4(pyz)][M(tdpd)2(pyz)]·6(H2O)}n, [1·10H2O and 2·10H2O where M = Co (1) and Zn (2)], consists of two types of crystallographically independent one-dimensional (1D) structures packed together. One motif, [M(tdpd)2(pyz)]2− (A), is an anionic infinite pyz bridged 1D array with chelating tdpd2− ligands, and the other motif is a cationic chain, [M(H2O)4(pyz)]2+ (B), which is decorated with four terminal water molecules. The 1D arrays (A) and (B) are arranged in parallel by multi-point hydrogen-bonding interactions in an alternate (A)(B)(A)(B) sequence extending along the c-axis. Both compounds exhibit structural transformations driven by thermal dehydration processes around 350 K to give partially dehydrated forms, 1·2H2O and 2·2H2O. The structural determination of the partially dehydrated form, 2·2H2O, reveals a solid-state structural transformation from a 1D chain structure to a two-dimensional (2D) coordination sheet structure, [Zn2(tdpd)2(H2O)2(pyz)]n (2·2H2O). Further heating to 500 K yields the anhydrous form 2. While the virgin samples of 1·10H2O and 2·10H2O crystallize in different crystal systems, powder X-ray diffraction (PXRD) measurements of the dehydrated forms, 1·2H2O and 2·2H2O, are indicative of the same structure. The structural transformation is irreversible for 1·10H2O at ambient conditions. On the other hand, compound 2·10H2O shows a reversible structural change. The solid-state structural transformation for 1·10H2O was also confirmed by monitoring in-situ magnetic susceptibility, which is consistent with other thermally-induced measurements.

scholarly journals Selective synthesis and structural transformation between a molecular ring-in-ring architecture and an abnormal trefoil knot

2020 ◽  
Vol 11 (30) ◽  
pp. 8013-8019 ◽  
Author(s):  
Li-Long Dang ◽  
Xiang Gao ◽  
Yue-Jian Lin ◽  
Guo-Xin Jin
Keyword(s):  
Structural Transformation ◽  
Solvent Effects ◽  
Chemical Reactivity ◽  
Structural Transformations ◽  
Selective Synthesis ◽  
Trefoil Knot ◽  
Ring Architecture

The chemical reactivity of Ag+ ions and solvent effects induce reversible structural transformations between an abnormal trefoil knot, a tetranuclear macrocycle and a ring-in-ring architecture.

scholarly journals Self-assembly of cyclic hexamers of γ-cyclodextrin in a metallosupramolecular framework with d-penicillamine

2020 ◽  
Vol 11 (34) ◽  
pp. 9246-9253
Author(s):  
Supattra Somsri ◽  
Naoto Kuwamura ◽  
Tatsuhiro Kojima ◽  
Nobuto Yoshinari ◽  
Takumi Konno
Keyword(s):  
Self Assembly ◽  
Porous Framework ◽  
Complex Anions

The complex anions with d-penicillamine are organized into a 3D porous framework that allows the inclusion of γ-CD. The inclusion is accompanied by the 3D-to-2D transformation of porous frameworks so as to accept cyclic hexamers of γ-CD.

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