[C–H⋯anion] interactions mediate the templation and anion binding properties of topologically non-trivial metal–organic structures in aqueous solutions

Abstract

We report the anion-recognition properties and anion-mediated templation of Metal-Organic knots and links in aqueous solutions.

Discovering privileged topologies of molecular knots with self-assembling models

“…In the past two decades there have been major breakthroughs in understanding the principles of directed self-assembly 1 – 10 , as well as for the synthesis of molecules with complex topologies 11 – 14 . Besides being appealing from a fundamental research perspective, molecular knots and links have versatile applications 11 , 14 – 16 , from anion sensing and assisted catalysis 17 – 19 , to seeding weaving structures 20 to their potential as molecular nano-cages 21 , functionalizable nanoscale scaffolds 22 – 24 , and the synthesis of polymers with special properties 25 – 31 . The challenges encountered in designing and then obtaining knotted molecular architectures lie in the numerous concurrent physico-chemical mechanisms that need to be balanced and steered.…”

Securing a Supramolecular Architecture by Tying a Stopper Knot

“…Accordingly, extrapolating knot properties between such disparate length scales, as with machine mechanisms,1 will not always be valid 2. Although a number of small‐molecule knots have been synthesized,3, 4 to date the knotting of a strand has only been exploited in functions that have no macroscopic counterpart (anion binding5a,5b and allosterically regulated5c and asymmetric5d catalysis) 1, 5, 6. In our everyday world, “stopper knots”7 are tied to prevent unreeving (that is, to prevent a strand from passing through a narrow aperture or slipping through another knot8).…”

Molekulare Knoten

“…[88] Die Struktur von 30 im Festkçrper zeigt zwei Br À -Ionen in der Knotenkavität, eins über dem anderen (Schema 10). [90] Wenn Cd II -Ionen als Te mplat verwendet wurden, ließen sich die Imingruppen des Knotens mit NaBH 4 reduzieren. [91] 3.…”

“…[88] Während des Kristallisationsprozesses werden zwei Bromidionen in der Kavitäteingelagert, eins über dem anderen. [90] Versuche, das System in der Abwesenheitvon Br À zu kristallisieren,schlugen fehl.…”

“…[117] Tr abolsis Kleeblattknoten (Schema 10) kçnnen transmetalliert werden, und es ist mçglich, das Anion in der zentralen Kavitäta uszutauschen (über Bindung von I À ,N 3 À , SCN À und NO 3 À wurde berichtet). [90,91] [120] Simulationen haben auch gezeigt, dass einige Knoten die bevorzugten Selbstassemblierungsprodukte von Lçsungen helicaler Bausteine mit "klebrigen" Enden sind. [121] Ebenso wurde die Position von Knoten in nicht-einheitlichen Polymeren untersucht.…”