scholarly journals Superphanes: Old Yet New Binding–Agents for Highly Selective Recognition of Fluoride by Size–Sieving Effect

2020 ◽  
Author(s):  
Qing He ◽  
Aimin Li ◽  
Shenglun Xiong ◽  
Wei Zhou ◽  
Huijuan Zhai ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Three Dimensions ◽  
High Symmetry ◽  
X Ray Crystallography ◽  
Design And Synthesis ◽  
Binding Agents ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Sieving Effect ◽  
Guest Chemistry

<p>Superphanes, namely percyclophanes, have been widely investigated for the sake of their aesthetically pleasing structures with high symmetry, intriguing physical and chemical properties and synthetic challenges. Nonetheless, the host–guest chemistry of superphanes remains to be an unmet challenge. Herein, we delineate the design, preparation, characterization, and host–guest chemistry of an unprecedented superphane <b>15</b>, which was evidenced by mass spectroscopy, NMR spectroscopy, X–ray crystallography, and DFT calculations. <b>15</b> features six bridges between two benzene planes, up to 18 C<sub>sp</sub>–<b>H</b> hydrogen–bonding donors well–distributed around the near–closed inner cavity in three dimensions. These allow <b>15</b> to exhibit exclusive selectivity towards F<sup>–</sup> against Cl<sup>–</sup>, Br<sup>–</sup>, I<sup>–</sup>, N<sub>3</sub><sup>–</sup>, SCN<sup>–</sup>, NO<sub>3</sub><sup>–</sup>, ClO<sub>4</sub><sup>–</sup>, SO<sub>4</sub><sup>2–</sup> and HP<sub>2</sub>O<sub>7</sub><sup>3–</sup> due to the size–sieving effect. This contribution opens up new opportunities for design and synthesis of new supramolecular hosts for anions of interest with high selectivity.<br></p>

Superphanes: Old Yet New Binding–Agents for Highly Selective Recognition of Fluoride by Size–Sieving Effect

2020 ◽  
Author(s):  
Qing He ◽  
Aimin Li ◽  
Shenglun Xiong ◽  
Wei Zhou ◽  
Huijuan Zhai ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Three Dimensions ◽  
High Symmetry ◽  
X Ray Crystallography ◽  
Design And Synthesis ◽  
Binding Agents ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Sieving Effect ◽  
Guest Chemistry

<p>Superphanes, namely percyclophanes, have been widely investigated for the sake of their aesthetically pleasing structures with high symmetry, intriguing physical and chemical properties and synthetic challenges. Nonetheless, the host–guest chemistry of superphanes remains to be an unmet challenge. Herein, we delineate the design, preparation, characterization, and host–guest chemistry of an unprecedented superphane <b>15</b>, which was evidenced by mass spectroscopy, NMR spectroscopy, X–ray crystallography, and DFT calculations. <b>15</b> features six bridges between two benzene planes, up to 18 C<sub>sp</sub>–<b>H</b> hydrogen–bonding donors well–distributed around the near–closed inner cavity in three dimensions. These allow <b>15</b> to exhibit exclusive selectivity towards F<sup>–</sup> against Cl<sup>–</sup>, Br<sup>–</sup>, I<sup>–</sup>, N<sub>3</sub><sup>–</sup>, SCN<sup>–</sup>, NO<sub>3</sub><sup>–</sup>, ClO<sub>4</sub><sup>–</sup>, SO<sub>4</sub><sup>2–</sup> and HP<sub>2</sub>O<sub>7</sub><sup>3–</sup> due to the size–sieving effect. This contribution opens up new opportunities for design and synthesis of new supramolecular hosts for anions of interest with high selectivity.<br></p>

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

scholarly journals Design and Synthesis of Fluoro Analogues of Vitamin D

2021 ◽  
Vol 22 (15) ◽  
pp. 8191
Author(s):  
Fumihiro Kawagoe ◽  
Sayuri Mototani ◽  
Atsushi Kittaka
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Fluorine Atom ◽  
Chemical Properties ◽  
Molecular Structures ◽  
Physical And Chemical Properties ◽  
Design And Synthesis ◽  
Synthetic Methodologies ◽  
Physical And Chemical ◽  
And Chemical Properties

The discovery of a large variety of functions of vitamin D3 and its metabolites has led to the design and synthesis of a vast amount of vitamin D3 analogues in order to increase the potency and reduce toxicity. The introduction of highly electronegative fluorine atom(s) into vitamin D3 skeletons alters their physical and chemical properties. To date, many fluorinated vitamin D3 analogues have been designed and synthesized. This review summarizes the molecular structures of fluoro-containing vitamin D3 analogues and their synthetic methodologies.

Defects in Intermetallic Compounds: How Do They Differ From Those in Ordinary Metals?

MRS Bulletin ◽  
1995 ◽  
Vol 20 (7) ◽  
pp. 29-36 ◽  
Author(s):  
Y.Q. Sun
Keyword(s):  
Intermetallic Compounds ◽  
Elastic Stress ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Three Dimensions ◽  
Superlattice Structure ◽  
Unit Cells ◽  
Line Defects ◽  
Physical And Chemical ◽  
And Chemical Properties

Just as in ordinary metals, defects in intermetallic compounds fall into three basic categories: point defects (vacancies, substitutional and interstitial atoms), line defects (dislocations), and planar defects (stacking faults, interfaces, grain boundaries). Also like ordinary metals, many important physical and chemical properties of intermetallic compounds are governed by the presence of these defects and the effects on them from temperature, composition, chemical environment, elastic stress state, and so on.What ultimately distinguishes an intermetallic compound from ordinary metals is its superlattice crystal structure. A two-dimensional analogue of the actual three-dimensional superlattice structure is shown in Figure 1a where the superlattice (unit cell marked by full lines) is made up of two identical sublat-tices (unit cells marked by dotted lines). A property of the sublattice is that it is exclusively occupied by one atom species, and accordingly sublattices are named after the atoms that occupy them, for example, the A and B sublattices in Figure 1a. In three dimensions, a super-lattice may consist of several sublattices. For example, the L12 superlattice of Ni3Al consists of four interpenetrating cubic sublattices, one occupied by Al atoms (Al sublattice), the other three by Ni atoms (Ni sublattices). When the sub-lattices are occupied exclusively by their designated atoms, the crystal is said to be fully ordered. The crystal will be partially ordered if a certain fraction of the sublattice sites is taken up by atoms that would otherwise sit at other sublattices; this fraction is used to describe the degree of long-range order.

scholarly journals Atomistic dynamics of sulfur-deficient high-symmetry grain boundaries in molybdenum disulfide

Nanoscale ◽  
2017 ◽  
Vol 9 (29) ◽  
pp. 10312-10320 ◽  
Author(s):  
Jinhua Hong ◽  
Yanlei Wang ◽  
Anle Wang ◽  
Danhui Lv ◽  
Chuanhong Jin ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Molybdenum Disulfide ◽  
Structural Defect ◽  
Chemical Properties ◽  
Common Type ◽  
High Symmetry ◽  
Physical And Chemical Properties ◽  
Bulk Crystals ◽  
Physical And Chemical ◽  
And Chemical Properties

As a common type of structural defect, grain boundaries play an important role in tailoring the physical and chemical properties of bulk crystals and their 2D counterparts such as graphene and MoS2.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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