Controlling the shape and chirality of an eight-crossing molecular knot

Knots are ubiquitous in the macroscopic world, with uses ranging from tying shoelaces to fishing, and they transform properties of thing that is tied. similarly found at nanoscale: for example, proteins DNA, also man-made polymers. These molecular entanglements, likewise, control molecules which tied—chain breakage polymers occurs most readily knotted point, knotting biomolecules can enhance stability. Herein, we describe formation a knot eight crossing points via one-pot self-assembly pair simple starting materials single metal salt. Further, as 819 form intrinsically topologically chiral, show diastereoselectively by using an enantiopure building block, allowing us use point chirality topological this complex architecture. •Subcomponent generates architecture crossings•Peripheral centers enforce additional nugatory crossings•The metal-organic be demetallated, forming organic loop 240 atoms•We chirality, enabling diastereoselective synthesis The impacts their function enables them carry out new tasks. Likewise, topologies underpin operation many synthetic machines. ability generate more architectures essential endow these machines advanced functions. Here, report points, consisting woven about six templating centers, dialdehyde diamine subcomponents structure topology were established NMR spectroscopy, mass spectrometry, X-ray crystallography. Upon demetallation, purely strand relaxes into symmetric conformation, while retaining original knot. 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Slow diffusion diisopropyl ether solution provided yellow crystals suitable analysis single-crystal diffraction. solid-state unambiguously confirmed 2 corresponds ligand atoms itself times. linkers two environments (for further details, see Section S3), highlighted pink orange 1. approximately coplanar. four cations pyridyl-imine groups, coordinated units, well anions, satisfy environment. Both enantiomers observed crystal, center inversion. similar result obtained iron(II) acetonitrile, yielding Fe-2 S5). possess crystallography S13). As congener, spheres completed anions. low field stabilizes high-spin state reflected longer Fe-N bond lengths 2.15 ± 0.04 Å. character caused exhibit paramagnetism, seen 1H spectrum contrast, inner adopted low-spin due groups each, shorter 1.98 0.03 Å.45Wood group equivalent eight-crossing possesses D4 symmetry.12Danon Scholar,46Zhang Acocella Calvaresi Zerbetto Effects tightness level.Proc. 116: 2452-2457Crossref metallated D2 symmetry appears, inspection, 16 total 2B). Eight nugatory: loops moved past other so effect removal without breaking re-joining 2B; Video S1). manipulations referred Reidemeister moves S6), representation altering topology.11Fielden Every deformed configuration exhibits minimal number possible points. 2B shows simplest representation: S6). https://www.cell.com/cms/asset/b9435513-0819-4d74-afb6-38525ec89b3c/mmc2.mp4Loading ... Download .mp4 (0.65 MB) Help files S1. Transformation Such conformation part conformational space accessible fully organic, non-labile 3 S14; S2), demetallation 3). Reduction BH3?THF acetonitrile:methanol (5:1, v:v) mixture transformation labile imine linkages holding parent fixed secondary amines,47Lavendomme Metal templates size macrocycles cages.J. 12147-12158Crossref 3, spectrometry S8). contrast 24 aromatic resonances 3B), only five 3C). constitutionally sections reside magnetically environments.12Danon Variable temperature experiments showed equivalence persist range 25°C ?50°C https://www.cell.com/cms/asset/cb94e1e2-3905-4f9a-9222-72b3f51af760/mmc3.mp4Loading (8.04 S2. Dynamics simulation inherently property resulting spatial connectivity. When achiral incorporated, expected racemic obtained. could distinguished adding tetrabutylammonium salt Lacour’s ?-TRISPHAT Zn-2,48Favarger Goujon-Ginglinger Monchaud Lacour Large-scale resolution TRISPHAT [Tris(tetrachlorobenzenediolato) phosphate(V)] anion.J. 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