We used molecular dynamics simulations to investigate the self-entanglements of the collapsed linear catenanes. We found two different types of topologically complex states. First, we observed numerous long-lived knotting events of the catenane backbone. However, comparison with conventional polymers reveals that knots are suppressed in catenanes. Next, we observed topologically complex states with no analogue in polymers, where a concatenated ring was threaded by other near or distal rings sliding through it. Differently from knots, these threaded states can disentangle by becoming fully tightened. A detailed thermodynamic and microscopic analysis is employed to rationalize the persistence of threaded states, which can survive significant internal reorganizations of the entire catenane. We finally discuss the broader implications of these previously unreported types of entanglements for other systems, such as noncollapsed and interacting catenanes.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10515615 | PMC |
http://dx.doi.org/10.1021/acsmacrolett.3c00315 | DOI Listing |
Chem Rev
January 2025
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
Template-directed synthesis has become a powerful methodology to access complex molecules. Noncovalent templating has been widely used in the last few decades, but less attention has been paid to covalent template-directed synthesis, despite the fact that this methodology was used for the first reported synthesis of a catenane. This review highlights the evolution of covalent templating over the last 60 years, thereby providing a toolbox for the design of efficient covalent templating processes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Straße 6, 44227, Dortmund, Germany.
Precise control over the catenation process in interlocked supramolecular systems remains a significant challenge. Here, we report a system in which a lantern-shaped PdL cage can dimerize to form two distinct PdL catenanes with different interlocking degree: a previously described quadruply interlocked double cage motif of D symmetry and an unprecedented triply interlocked structure of C symmetry. While the former structure features a linear arrangement of four Pd(II) centers, separated by three mechanically linked pockets, the new motif has a staggered shape.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
Macrocycles represent one important class of functional molecules, and dynamic macrocycles with the potential of cleavability, adaptability, and topological conversion are challenging. Herein we report photoswitchable allosteric and topological control of dynamic covalent macrocycles and further the use in guest binding and mechanically interlocked molecules. The manipulation of competing ring-chain equilibria and bond formation/scission within reaction systems enabled light-induced structural regulation over dithioacetal and thioacetal dynamic bonds, accordingly realizing bidirectional switching between crown ether-like covalent macrocycles and their linear counterparts.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
College of Chemistry and Chemical Engineering, Luoyang Normal University, Henan Province Function-Oriented Porous Materials Key Laboratory, Luoyang, 471934, P. R. China.
The synthesis of high-ordered mechanically interlocked supramolecular structures is an extremely challenging topic. Only two linear [4]catenanes have been reported so far and there is no defined strategy to obtain cyclic [4]catenane. Herein, two unprecedented cyclic [4]catenanes, 1 and 2, were prepared in high yields.
View Article and Find Full Text PDFChemistry
December 2024
School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
Cage-catenanes are chemical constructs where two or more cage-like molecules or assemblies are mechanically interlocked together. We report a new class of cage-catenanes where dimeric metal-organic cage-catenanes are linked into larger assemblies through additional bridging metal chloride links. These crystalline materials are obtained from the reaction of tris(nicotinoyl)cyclotriguaiacylene (L1) with Cu(II) salts, and all feature a tetramer of cages where two {Cu(L1)(X)} cages (X=anion) are mechanically interlocked, and link to each other and to another {Cu(L1)(X)} cage-catenane through a planar, linear tetranuclear {Cu(μ-Cl)Cl} cluster.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!