Taco complex templation based on the bis(m-phenylene)-32-crown-10/paraquat recognition motif is used to develop a general method for preparing mechanically interlocked molecules. A [2]rotaxane and a [2]catenane were synthesized in high yields by a ring-closing metathesis reaction, which was owed to the impactful template effect. Due to the high symmetry of (5,5')-difunctional bis(m-phenylene)-32-crown-10 derivatives, this taco complex templated synthesis has potential to be a tempting method to solve a symmetry-based problem in the fabrication of complicated mechanically interlocked structures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Rotaxanes have demonstrated great potential in the development of smart materials owing to their attractive dynamic and movable properties. However, it remains a significant challenge to construct polymers with outstanding mechanical performance by the introduction of rotaxane units. Here, we synthesized several pillar[5]arene-based [2]rotaxanes by condensation reaction of 1-naphthyl isocyanate and alkyl diamines and introduced them into covalent polymers through ring-opening metathesis polymerization. The rigid and bulky pillar[5]arene units, sliding motions of rotaxane moieties, and intra- and intermolecular hydrogen bonds between urea groups endow the polymers with excellent mechanical properties (PR4: Young's modulus = 360.1 ± 32.1 MPa, yield stress = 14.2 ± 0.1 MPa, stress at break = 14.8 ± 0.6 MPa, and toughness = 67.8 ± 2.0 MJ/m3). Moreover, the mechanical properties of PR4 could be weakened and strengthened by the introduction of Ac– and Cl–, respectively, showing their abundant regulable features. These findings provide novel insights into the preparation of advanced supramolecular materials with enhanced mechanical properties.
Bildet eine Kette: Ein Copillararen-Monomer bildet in Lösung ein lineares supramolekulares Polymer (siehe Bild). Einkristall-Röntgenstrukturanalysen und NMR-Spektren belegen die enthalpisch angetriebene Aggregation über vierfache CH⋅⋅⋅π-Wechselwirkungen zwischen dem Octylrest (blau) und dem mit aromatischen Gruppen ausgekleideten Hohlraum (rot).
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The dynamic duo: Different topologies of dynamic supramolecular polymers, such as linear (see picture, left) and cross-linked species (right), can be reversibly interconverted by external stimuli that utilize host–guest and metal–ligand non-covalent recognition motifs. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Driven by orthogonal pillar[5]arene-based and crown ether-based molecular recognitions, a dynamic [1]catenane with pH-responsiveness was constructed via threading-followed-by-complexation.
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