Self-assembled [2]catenane in trapezoidal metallacycles with [Cp*Ir]-corners

Abstract

A series of trapezoidal metallacycles were synthesized by the selective combination of a rigid with a flexible arm. [2]Catenane 3 was obtained by self-assembly when the cavity size of the trapezoidal rings was optimised.

Coordination-driven self-assembly of a molecular figure-eight knot and other topologically complex architectures

“…48), indicating that the Donor–Acceptor stacking interactions are strong enough to maintain the [2]catenane topology even in dilute solutions. This phenomenon contrasts with those observed in recent studies on [2]catenane structures 31,46,47 .…”

Selective Synthesis of Discrete Mono‐, Interlocked‐, and Borromean Ring Ensembles Based on a π‐Electron‐Deficient Ligand

“…According to the Le Chatelier's principle, changes in concentration may promote ar eversible conversion between catenane structures and their metallarectangles due to the dynamic behavior of the metal-ligand binding and the weak interactions between the subunits. 20 In general, coordination-driven self-assembly favors the formation of interlocked metallasupramolecules at high concentrations, whiled isfavoring interlocked structuresa t lower concentrations.A se xpected, the proportion of 2a in methanoli ncreases with the concentrationo ft he reactants, and the reaction carriedo ut at 8.0 mM (with respectt om onorectangle 3a)p rovided the maximum concentration (79 %) of 2a ( Figure S2). This indicates that the self-assembly of B2 and Scheme1.Self-assembly of mono-, interlocked-and Borromean rings.…”

Dynamic Interconversion between Solomon Link and Trapezoidal Metallacycle Ensembles Accompanying Conformational Change of the Linker

“…1 HNMR spectra were recorded on a Bruker Avance I4 00 spectrometer at room temperature and referenced to the signal of the residual protonated solvent (dH = 3.31 ppm (CD 3 OD), dH = 1.94 ppm (CD 3 CN)). Elemental analysis calcd (%) for C 116 H 100 F 12 1709,1671,1615,1575,1526,1453,1415,1374,1342,1274,1212,1146,1022,969,765, 632 cm À1 ;E SI-TOF-MS: m/z: 1261.625 (calcd for [MÀ2OTf -] 2 + :1 261.627). Elemental analyses were performed on an Elementar Vario EL III analyzer.I Rs pectra of the solid samples (KBr pellets) were recorded in the range 400-4000 cm À1 on aN icolet Avatar 360 IR spectrometer.E SI mass spectra were recorded on an Impact II UHR-TOF mass spectrometer.…”

“…[12] Results and Discussion Self-assemblyo fS olomon link Initially,l igand L was combined with B1 in methanolic solution for 24 hu nder ambient conditions, and then the mixture was concentrated under reduced pressure (Scheme 2). We envisaged that the self-assemblyofL Z and B1 may lead to the formation of aSolomon link, which would be stabilized by multiple p-p stacking interactions betweent he NDI groups and hydrogen-bonding interactions,w hile the length parity between L U and B1 may enable the self-assembly of ad inuclear trapezoidal metallacycle (Scheme 1).…”

“…Ligand L was selected as it can adopt two main conformations, a Z ‐form with one pyridyl ring on either side of the NDI spacer, or a U ‐form with two pyridyl rings on the same side of the NDI spacer, due to rotation of the pyridyl groups about the methylene groups (Scheme ). We envisaged that the self‐assembly of L Z and B1 may lead to the formation of a Solomon link, which would be stabilized by multiple π–π stacking interactions between the NDI groups and hydrogen‐bonding interactions, while the length parity between L U and B1 may enable the self‐assembly of a dinuclear trapezoidal metallacycle (Scheme ) …”