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The use of aminals in dynamic covalent chemistry is slightly underexplored, probably due to their inherent instability. Here we report the spontaneous [2+2] macrocyclization of tetrakis(aminals). Their unexpected stability and structural modularity, the dynamic nature of the connections and their water tolerance make them appealing systems for future applications as stimulus-responsive materials.
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http://dx.doi.org/10.1039/d0cc07184f | DOI Listing |
Angew Chem Int Ed Engl
August 2025
Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou, 310058, P.R. China.
The precise synthesis of stereochemically controlled multicavity macrocyclic hosts based on pillar[n]arenes presents a significant challenge in supramolecular chemistry. This difficulty primarily stems from the spontaneous generation of planar chirality-induced stereoisomer mixtures during synthetic procedures, which considerably complicates the isolation process. In this study, we introduce a social chiral self-sorting strategy utilizing a triangular gold complex, enabling the stereochemically controlled synthesis of [9]cycloparaphenylene-pillar[5]arene trimers ([9]CPP-3P[5]A).
View Article and Find Full Text PDFInorg Chem
August 2025
Univ Brest, UMR-CNRS 6521 CEMCA, 6 avenue Victor le Gorgeu, Brest 29238, France.
Two derivatives of tacn (1,4,7-triazacyclononane) are investigated for their complexation with Cu(II), Zn(II), and Mn(II). The different denticities of macrocyclic ligands and offer the possibility to modulate the coordination environment and stability of the complexes. [Cu()]ClO(HO) exhibits a square-pyramidal penta-coordinated geometry in the solid state, while UV-visible and EPR spectroscopies and DFT are consistent with a hexa-coordinated species in solutions.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2025
Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Univ, CNRS UMR 7325, Campus de Luminy, case 913, Marseille cedex 09, 13288, France.
An electron-deficient tetranitroazacalixarene is shown to undergo reversible cyanide capture via nucleophilic aromatic substitution, yielding an unprecedented class of metastable dianionic macrocycle incorporating two Meisenheimer units, fully characterized by single-crystal X-ray diffraction, NMR, and electronic absorption spectroscopies. Acting as a chemical fuel, cyanide transiently drives the formation of this adduct, which can spontaneously regenerate the parent macrocycle under mild conditions, representing a rare demonstration of metastability in a Meisenheimer complex. The dynamic behavior of this system, reminiscent of out-of-equilibrium assemblies, is finely tunable through macrocycle concentration, counterion nature, solvent, and temperature.
View Article and Find Full Text PDFChemistry
August 2025
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8502, Japan.
Backbone thiazole (Thz) moieties prevail in bioactive peptidic natural products and play important roles in their biological functions. However, the de novo discovery of artificial Thz-containing peptide ligands remains challenging. Here, we report an mRNA display-based selection platform for Thz-containing macrocyclic peptides (teMP), established through a dedicated posttranslational chemoenzymatic transformation.
View Article and Find Full Text PDFInorg Chem
April 2025
Department of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic.
As Mn(II) complexes attract continuous interest as alternatives to Gd-based contrast agents (CAs) in clinical magnetic resonance imaging (MRI), we synthesized two monosubstituted derivatives of the 15-membered pyridine-based macrocycle 15-pyNO bearing either a 2-pyridylmethyl () or a 2-benzimidazolylmethyl pendant arm () and characterized their Mn(II) complexes and in the context of MRI contrast agent development. Their X-ray molecular structures confirmed a coordination number of seven and a pentagonal bipyramidal geometry with one coordination site available for inner-sphere water. Protonation constants of and , and stability constants with selected divalent metal ions were determined using potentiometry.
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