Rational design of two-dimensional covalent tilings using a C6-symmetric building block via on-surface Schiff base reaction

2019 ◽  
Vol 55 (9) ◽  
pp. 1326-1329 ◽  
Author(s):  
Cheng Lu ◽  
Yang Li ◽  
Li-Mei Wang ◽  
Hui-Juan Yan ◽  
Long Chen ◽  
...  

Two-dimensional covalent triangular, rhombille and semi-regular tilings are constructed successfully using C6-symmetric building blocks via on-surface Schiff base reaction.

2021 ◽  
Vol 7 (23) ◽  
pp. eabf9402
Author(s):  
Katherine C. Elbert ◽  
William Zygmunt ◽  
Thi Vo ◽  
Corbin M. Vara ◽  
Daniel J. Rosen ◽  
...  

The use of nanocrystal (NC) building blocks to create metamaterials is a powerful approach to access emergent materials. Given the immense library of materials choices, progress in this area for anisotropic NCs is limited by the lack of co-assembly design principles. Here, we use a rational design approach to guide the co-assembly of two such anisotropic systems. We modulate the removal of geometrical incompatibilities between NCs by tuning the ligand shell, taking advantage of the lock-and-key motifs between emergent shapes of the ligand coating to subvert phase separation. Using a combination of theory, simulation, and experiments, we use our strategy to achieve co-assembly of a binary system of cubes and triangular plates and a secondary system involving two two-dimensional (2D) nanoplates. This theory-guided approach to NC assembly has the potential to direct materials choices for targeted binary co-assembly.


Nanoscale ◽  
2021 ◽  
Author(s):  
Antonios Raptakis ◽  
Arezoo Dianat ◽  
Alexander Croy ◽  
Gianaurelio Cuniberti

This computational study establishes a correlation between the elastic properties of COFs and their building-blocks towards the rational design of new materials with tailored properties.


2012 ◽  
Vol 68 (11) ◽  
pp. m306-m308
Author(s):  
Jun-Wei Ye ◽  
Li-Mei Zhao ◽  
Wei Li ◽  
Gui-Ling Ning

In the title cadmium metal–organic framework complex, [Cd(C8H3NO6)(C24H16N2)]nor [Cd(NIPH)(dpphen)] (NIPH is nitroisophthalate and dpphen is 4,7-diphenyl-1,10-phenanthroline), the unique CdIIcation in a general position is coordinated by four carboxy O atoms from three symmetry-related NIPH anions and two N atoms from a dpphen ligand. The CdIIcations are bridged by pairs of NIPH anions to generate a dinuclear molecular building block, [Cd2N4(CO2R)4], with a Cd...Cd separation of 4.0936 (10) Å. Each such building block is connected to four adjacent dinuclear building blocks by NIPH anions, resulting in a two-dimensional layer framework in thebcplane. The dpphen ligands occupy the space between these layers and are linked by π–π interactions, with a separation of 3.4541 (6) Å between the central aromatic rings of inversion-related dpphen ligands. The thermogravimetric and photoluminescent properties of the complex have also been investigated.


2018 ◽  
Author(s):  
Enrico Berardo ◽  
Rebecca L. Greenaway ◽  
Lukas Turcani ◽  
Ben M. Alston ◽  
Michael J. Bennison ◽  
...  

<p>A completely unsymmetrical porous organic cage was synthesized from a C<i>2v </i>symmetrical building block that was identified by a computational screen. The cage was formed through a 12-fold imine condensation of a tritopic C<i>2v </i>symmetric trialdehyde with a di-topic C<i>2 </i>symmetric diamine in a [4+6] reaction. The cage was rigid and microporous, as predicted by the simulations, with an apparent Brunauer-Emmett-Teller surface area of 578 m2 g-1. The reduced symmetry of the tritopic building block relative to its topicity meant there were 36 possible structural isomers of the cage. Experimental characterization suggests a single isomer with 12 unique imine environments, but techniques such as NMR could not conclusively identify the isomer. Computational structural and electronic analysis of the possible isomers was used to identify the most likely candidates, and hence to construct a 3-dimensional model of the amorphous solid. The rational design of unsymmetrical cages using building blocks with reduced symmetry offers new possibilities in controlling the degree of crystallinity, porosity, and solubility, of self-assembled materials.</p>


2018 ◽  
Author(s):  
Enrico Berardo ◽  
Rebecca L. Greenaway ◽  
Lukas Turcani ◽  
Ben M. Alston ◽  
Michael J. Bennison ◽  
...  

<p>A completely unsymmetrical porous organic cage was synthesized from a C<i>2v </i>symmetrical building block that was identified by a computational screen. The cage was formed through a 12-fold imine condensation of a tritopic C<i>2v </i>symmetric trialdehyde with a di-topic C<i>2 </i>symmetric diamine in a [4+6] reaction. The cage was rigid and microporous, as predicted by the simulations, with an apparent Brunauer-Emmett-Teller surface area of 578 m2 g-1. The reduced symmetry of the tritopic building block relative to its topicity meant there were 36 possible structural isomers of the cage. Experimental characterization suggests a single isomer with 12 unique imine environments, but techniques such as NMR could not conclusively identify the isomer. Computational structural and electronic analysis of the possible isomers was used to identify the most likely candidates, and hence to construct a 3-dimensional model of the amorphous solid. The rational design of unsymmetrical cages using building blocks with reduced symmetry offers new possibilities in controlling the degree of crystallinity, porosity, and solubility, of self-assembled materials.</p>


Author(s):  
Dorian Bader ◽  
Johannes Fröhlich ◽  
Paul Kautny

The facile preparation of three regioisomeric thienopyrrolocarbazoles applying a convenient C-H activation approach is presented. Derived from indolo[3,2,1-<i>jk</i>]carbazole, the incorporation of thiophene into the triarylamine framework significantly impacted the molecular properties of the parent scaffold. The developed thienopyrrolocarbazoles enrich the family of triarylamine donors and constitute a novel building block for functional organic materials.


2019 ◽  
Author(s):  
Dorian Bader ◽  
Johannes Fröhlich ◽  
Paul Kautny

The facile preparation of three regioisomeric thienopyrrolocarbazoles applying a convenient C-H activation approach is presented. Derived from indolo[3,2,1-<i>jk</i>]carbazole, the incorporation of thiophene into the triarylamine framework significantly impacted the molecular properties of the parent scaffold. The developed thienopyrrolocarbazoles enrich the family of triarylamine donors and constitute a novel building block for functional organic materials.


Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 118
Author(s):  
Jean-Laurent Pouchairet ◽  
Carole Rossi

For the past two decades, many research groups have investigated new methods for reducing the size and cost of safe and arm-fire systems, while also improving their safety and reliability, through batch processing. Simultaneously, micro- and nanotechnology advancements regarding nanothermite materials have enabled the production of a key technological building block: pyrotechnical microsystems (pyroMEMS). This building block simply consists of microscale electric initiators with a thin thermite layer as the ignition charge. This microscale to millimeter-scale addressable pyroMEMS enables the integration of intelligence into centimeter-scale pyrotechnical systems. To illustrate this technological evolution, we hereby present the development of a smart infrared (IR) electronically controllable flare consisting of three distinct components: (1) a controllable pyrotechnical ejection block comprising three independently addressable small-scale propellers, all integrated into a one-piece molded and interconnected device, (2) a terminal function block comprising a structured IR pyrotechnical loaf coupled with a microinitiation stage integrating low-energy addressable pyroMEMS, and (3) a connected, autonomous, STANAG 4187 compliant, electronic sensor arming and firing block.


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 503
Author(s):  
Morten Gundersen ◽  
Guro Austli ◽  
Sigrid Løvland ◽  
Mari Hansen ◽  
Mari Rødseth ◽  
...  

Sustainable methods for producing enantiopure drugs have been developed. Chlorohydrins as building blocks for several β-blockers have been synthesized in high enantiomeric purity by chemo-enzymatic methods. The yield of the chlorohydrins increased by the use of catalytic amount of base. The reason for this was found to be the reduced formation of the dimeric by-products compared to the use of higher concentration of the base. An overall reduction of reagents and reaction time was also obtained compared to our previously reported data of similar compounds. The enantiomers of the chlorohydrin building blocks were obtained by kinetic resolution of the racemate in transesterification reactions catalyzed by Candida antarctica Lipase B (CALB). Optical rotations confirmed the absolute configuration of the enantiopure drugs. The β-blocker (S)-practolol ((S)-N-(4-(2-hydroxy-3-(isopropylamino)propoxy)phenyl)acetamide) was synthesized with 96% enantiomeric excess (ee) from the chlorohydrin (R)-N-(4-(3-chloro-2 hydroxypropoxy)phenyl)acetamide, which was produced in 97% ee and with 27% yield. Racemic building block 1-((1H-indol-4-yl)oxy)-3-chloropropan-2-ol for the β-blocker pindolol was produced in 53% yield and (R)-1-((1H-indol-4-yl)oxy)-3-chloropropan-2-ol was produced in 92% ee. The chlorohydrin 7-(3-chloro-2-hydroxypropoxy)-3,4-dihydroquinolin-2(1H)-one, a building block for a derivative of carteolol was produced in 77% yield. (R)-7-(3-Chloro-2-hydroxypropoxy)-3,4-dihydroquinolin-2(1H)-one was obtained in 96% ee. The S-enantiomer of this carteolol derivative was produced in 97% ee in 87% yield. Racemic building block 5-(3-chloro-2-hydroxypropoxy)-3,4-dihydroquinolin-2(1H)-one, building block for the drug carteolol, was also produced in 53% yield, with 96% ee of the R-chlorohydrin (R)-5-(3-chloro-2-hydroxypropoxy)-3,4-dihydroquinolin-2(1H)-one. (S)-Carteolol was produced in 96% ee with low yield, which easily can be improved.


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