Different types of multinuclear half-sandwich rhodium macrocycles and cages were designed and synthesized by using two similar multifunctional hydroxamate ligands (pyrazine-2-hydroxamic acid (NaHL ) and 4,4'-bipyridine-2-hydroxamic acid (KHL )) featuring one monodentate site and two pairs of chelating sites. The Rh -Pd heterometallic macrocycles were constructed by using the semi-open palladium(II) source [Pd(en)Cl ] with two free acceptor sites. However, only one kind of macrocycle was found when the shorter ligand L was used, while in for the larger ligand, various spectroscopic techniques demonstrated the coexistence of hexanuclear and octanuclear macrocycles in solution and the proportions of both components depended on concentration and temperature. The palladium salt Pd(NO ) , as a source of "naked" Pd , was introduced to assemble the cuboid-shaped cage composed of two types of metal ions and three types of organic ligands. In addition, two silver(I)-containing mixed-metal complexes bridged by pyrazine were obtained, in which two forms of decanuclear complex with C and C point symmetry cocrystallized-one is a polymeric structure and the other is a discrete cage. However, the third form, with D point symmetry, was found in the larger cage.
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Angew Chem Int Ed Engl
January 2025
Department of Chemistry, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, P. R. China.
Integrating two or more materials to construct membranes with heterogeneous pore structures is an effective strategy for enhancing separation performance. Regularly arranging these heterogeneous pores can significantly optimize the combined effect of the introduced components. Porous Organic Cages (POCs), an emerging subclass of porous materials composed of discrete molecules, assemble to form interconnected pores and exhibit permanent porosity in the solid state.
View Article and Find Full Text PDFChemistry
January 2025
School of Chemistry and Chemical Engineering, Nanchang University, 999 Xuefu avenue, Nanchang, 330031, China.
Macrocycles and cages are very attractive for the development of functional materials due to their unique inner cavities. Building blocks with interesting functions and synthetic conveniences are especially attractive. Tetraphenylethylene (TPE) is such an entity with C symmetry and tetrakis-functional groups easily modifiable.
View Article and Find Full Text PDFNat Rev Chem
January 2025
School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai, China.
A captivating challenge in chemistry lies in achieving robust and precise binding of uncharged, hydrophilic carbohydrate entities. Although past decades have provided a variety of excellent molecular architectures tailored for carbohydrate recognition, including acyclic receptors, macrocycles and foldamers, recent advances have highlighted the potential of synthetic molecular cages. These structures are equipped with intricately designed cavities that contain bespoke noncovalent binding sites for carbohydrate interactions.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Metal-organic cages and capsules exhibit space-specific functions based on their discrete hollow structures. To acquire enzyme-like asymmetric or intricate structures, they have been modified by desymmetrization with two or more different ligands. There is a need to establish new strategies that can desymmetrize structures in a simple way using only one type of ligand, which is different from the mixed-ligand approach.
View Article and Find Full Text PDFBeilstein J Org Chem
November 2024
Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Straße 6, 44227 Dortmund, Germany.
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