A series of covalent organic frameworks substituted with azo groups (AzoCOFs) have been synthesized via imine condensation. The obtained frameworks show crystallinity and high stability. More importantly, the AzoCOFs exhibit exceptionally high ideal adsorption solution theory (IAST) selectivity in adsorption of CH (35-2891) over CH at 273 K and 1 bar, owing to the favorable interactions between azo groups and acetylene molecules. The dependence of the gas adsorption property on pore size and polarity of the frameworks was also studied. The triethylene glycol substituted shows the highest CH/CH selectivity (IAST selectivity of 2891), which represents the highest reported for all porous materials. The AzoCOFs also exhibit high IAST adsorption selectivity of CH/CH (11-20), CH/CH (15-22), and CO/CH (12-37), which is comparable with most porous materials, thus showing their great potential in gas separation applications.
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http://dx.doi.org/10.1021/acsami.0c15328 | DOI Listing |
Chemistry
January 2025
Hokkaido University: Hokkaido Daigaku, Research Institute for Electronic Science, JAPAN.
We serendipitously discovered a novel series of azoheteroarene dyes capable of detecting pH variations in near-neutral solutions. These dyes feature thiazole, thiadiazole, triazole, pyrazole, or benzothiazole heteroaryls linked to hydroxyphenyl azo groups. They exhibit distinctive light absorption properties in aqueous solutions and show notable color changes in a narrow pH range, visible to the naked eye.
View Article and Find Full Text PDFJ Appl Toxicol
January 2025
Laboratory of Genetic Toxicology, Lutheran University of Brazil (ULBRA), Canoas, Rio Grande do Sul, Brazil.
The widespread use of electronic devices has led to increased blue light exposure, highlighting the need for effective radiation blockers with blue light protection. Two synthetic 2-(2'-hydroxyphenyl)benzoxazole derivatives named azo-4'-benzoxazole and azo-5'-benzoxazole have shown an unprecedented blue light absorption capacity but had not been subjected to a safety evaluation. This study aimed to evaluate the cytotoxic, genotoxic, and mutagenic activities of these compounds.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh.
This work represents a systematic computational study of structural and optoelectronic properties of 24 phenylazo-2-naphthol derivatives using the DFT-B3LYP/6-31 + G(d,p) method. The positional isomers of azo compounds have been designed by introducing an azophenyl unit (with and without substituents) at three different (1-, 3-, and 4-) positions of 2-naphthols. This result shows that depending on the linking position of the azophenyl unit and substituents (NO and maleimide), the -azo, -azo, and hydrazo forms of our substituted azo derivatives possess distinguished UV-vis absorption and charge-transfer properties compared to unsubstituted Sudan I derivatives.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
pH-responsive polyamidoamine (PAMAM) dendrimers are used as well-defined building blocks to design light-switchable nano-assemblies in solution. The complex interplay between the photoresponsive di-anionic azo dye Acid Yellow 38 (AY38) and the cationic PAMAM dendrimers of different generations is presented in this study. Electrostatic self-assembly involving secondary dipole-dipole interactions provides well-defined assemblies within a broad size range (10 nm-1 μm) with various shapes.
View Article and Find Full Text PDFFungal Biol
February 2025
Wageningen Plant Breeding Research, Mushroom Research Group, the Netherlands. Electronic address:
To visualize the nonself recognition reaction in the cultivated mushroom Agaricus bisporus, we developed a method using the azo dye Evans blue. The use of Evans blue highlights dead mycelial sections, which are produced following nonself recognition in the interaction zone between two individuals. This method can differentiate between distinct heterokaryons, as well as between closely related heterokaryons constructed from siblings.
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