The synthesis of a set of bipyridine-containing macrocycles by oxidative acetylene-acetylene dimerization is described. The cycles are separated by preparative GPC, and the smallest homologue is analyzed by single-crystal X-ray diffraction, which shows a layered structure with channels that are partially filled with parts of the flexible chains of adjacent macrocycles. The cyclic trimer has a D3h symmetry and is a possible candidate for the formation of metal organic supramolecular assemblies on surfaces.
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http://dx.doi.org/10.1021/ol800316b | DOI Listing |
Anticancer Agents Med Chem
January 2025
Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle (Saale), Germany.
Objective: In this study, 25 synthetic cyclic lipopeptides (CLPs) were investigated for their anticancer potential against mouse melanoma (B16F10) cells, human prostate cancer (PC-3), human colorectal adenocarcinoma (HT-29) and mouse embryonic fibroblast (NIH3T3) cells.
Methods: The cytotoxic activity of investigated compounds was evaluated using MTT and CV assays. In order to examine the mechanism of action of the most potent compound cell cycle analysis, apoptosis assay, caspase activity, CFSE and DHR staining, DAF-FM, autophagy and immunocytochemistry caspase-3 assays were performed.
J Am Chem Soc
January 2025
Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.
A series of Ni complexes bearing a redox and acid-base noninnocent tetraamido macrocyclic ligand, H-(TAML-4) {H-(TAML-4) = 15,15-dimethyl-5,8,13,17-tetrahydro-5,8,13,17-tetraaza-dibenzo[]cyclotridecene-6,7,14,16-tetraone}, with formal oxidation states of Ni, Ni, and Ni were synthesized and characterized structurally and spectroscopically. The X-ray crystallographic analysis of the Ni complexes revealed a square planar geometry, and the [Ni(TAML-4)] complex with the formal oxidation state of Ni was characterized to be [Ni(TAML-4)] with the oxidation state of the Ni ion and the one-electron oxidized TAML-4 ligand, TAML-4. The Ni oxidation state and the TAML-4 radical cation ligand, TAML-4, were supported by X-ray absorption spectroscopy and density functional theory calculations.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
National University of Singapore - Kent Ridge Campus: National University of Singapore, Department of Chemistry, Faculty of Science, 3 Science Drive 3, 117543, Singapore, SINGAPORE.
Figure-eight macrocycles represent a fascinating class of π-conjugated units characterized by unique aesthetics and non-contact molecular crossing at the center. Despite progress in synthesis over the past century, research into inorganic, organic, and polymeric figure-eight materials remains in its infancy. Here we report the first examples of figure-eight covalent organic frameworks by condensing figure-eight knots to create extended porous figure-eight π architectures.
View Article and Find Full Text PDFACS Macro Lett
January 2025
Faculty of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China.
Efficient synthesis of cyclic polymers remains a frontier challenge. We report here that macromolecular transesterification during a pseudoblock copolymerization process can be utilized for such a purpose. Organobase-catalyzed ring-opening alternating copolymerization of 3,4-dihydrocoumarin and epoxide is conducted with four-armed poly(ethylene oxide) (PEO) as a macroinitiator.
View Article and Find Full Text PDFNatl Sci Rev
January 2025
Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, Department of Chemistry and Chemical Engineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Constructing 3D functional covalent organic frameworks (COFs) with both robust linkage and planar macrocycle building blocks still remains a challenge due to the difficulty in adjusting both the crystallinity and the dominant 2D structures. In addition, it is also challenging to selectively convert inert C(sp)-H bonds into value-added chemicals. Herein, robust 3D COFs, USTB-28-M (M=Co, Ni, Cu), have been polymerized from the nucleophilic aromatic substitution reaction of -symmetric 2,3,6,7,14,15-hexahydroxyltriptycene with -symmetric hexadecafluorophthalocyanine (MPcF) under solvothermal conditions.
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