[structure: see text] We present a novel type of molecular capsule formed by self-organization of calix[4]arenes with several oppositely charged functional groups located at their upper rims. In highly polar solvents, the complementary half-spheres form stable 1:1 complexes with association constants of up to 7 x 10(5) M(-)(1) in methanol. The cavity inside the capsules is large enough for the inclusion of small aliphatic or (hetero)aromatic guest molecules.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ol0257631 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany.
Free ions in organic solvents of low polarity would be valuable tools for the activation of low-reactivity substrates. However, the formation of unreactive ion pairs at concentrations relevant for synthesis has prevented the success of this concept so far. On the example of highly nucleophilic pyridinamide phosphonium salts in dichloromethane, we show that asymmetric aggregation offers a solution to this general problem.
View Article and Find Full Text PDFChem Asian J
January 2025
Birla Institute of Technology & Science Pilani - Hyderabad Campus, Chemistry, Jawaharnagar, Shamirpet Mandal, 500078, Hyderabad, INDIA.
Despite significant advancements in the structural flexibility and functional diversity of fluorescent molecular sensors, the chromophores often require complex synthetic processes and are typically designed to perform only a specific function. Herein, we have demonstrated the unique features of fluorophores based on a fused coumarin-indole scaffold, which are synthetically available via a one-step reaction. Four fluorophores (ICH, ICEst, ICOMe, and ICNMe2) with varying substituents were synthesized and characterized.
View Article and Find Full Text PDFMetabolites
January 2025
Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, Ex-Hacienda San Juan Molino Carretera Estatal Tecuexcomac-Tepetitla Km 1.5, Tlaxcala C.P. 90700, Mexico.
: Jacq. (HP) is widely recognized in traditional medicine for its antimicrobial properties, which are attributed to secondary metabolites such as phenolic compounds, alkaloids, and terpenes. f.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States.
Conventional methods for extracting rare earth metals (REMs) from mined mineral ores are inefficient, expensive, and environmentally damaging. Recent discovery of lanmodulin (LanM), a protein that coordinates REMs with high-affinity and selectivity over competing ions, provides inspiration for new REM refinement methods. Here, we used quantum mechanical (QM) methods to investigate trivalent lanthanide cation (Ln) interactions with coordination systems representing bulk solvent water and protein binding sites.
View Article and Find Full Text PDFPhotochem Photobiol Sci
January 2025
CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535, Coimbra, Portugal.
Solvatochromism exhibited by azobenzene-4-sulfonyl chloride (here abbreviated as Azo-SCl) has been investigated in a series of non-polar, polar-aprotic and polar-protic solvents. The UV-vis spectra of Azo-SCl exhibit two long-wavelength bands, observed at 321-330 nm (band-I) and 435-461 nm (band-II), which are ascribed to the π*-π (S ← S) and π*-n (S ← S) transitions, respectively. The shorter wavelength band indicates a reversal in solvatochromism, from negative to positive solvatochromism, for a solvent with a dielectric constant of 32.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!