A Dual-Responsive Supra-Amphiphilic Polypseudorotaxane Constructed from a Water-Soluble Pillar[7]arene and an Azobenzene-Containing Random Copolymer

Macromolecular supra-amphiphiles refer to a kind of macromolecular amphiphiles whose hydrophlic and hydrophobic parts are connected by noncovalent forces. They have applications in various fields, such as drug delivery, sensor systems, and biomedical materials. Here we report a novel molecular recognition motif between a new thermoresponsive water-soluble pillar[7]­arene (<b>WP7</b>) and an azobenzene derivative. Furthermore, we utilized this recognition motif to construct the first pillararene-based supra-amphiphilic polypseudorotaxane which can self-assemble to form vesicles in water. Due to the dual-responsiveness of the molecular recognition motif (the thermoresponsiveness of <b>WP7</b> and photoresponsiveness of azobenzene), the reversible transformations between solid nanospheres based on the self-assembly of the polymer backbone and vesicles based on the self-assembly of the supra-amphiphilic polypseudorotaxane were achieved by adjusting the solution temperature or UV–visible light irradiation. These dual-responsive aggregation behaviors were further used in the controlled release of water-soluble dye calcein molecules

Dual-Responsive [2]Pseudorotaxane On the basis of a pH-Sensitive Pillar[5]arene and Its Application in the Fabrication of Metallosupramolecular Polypseudorotaxane

Metallosupramolecular polymer, an appealing polymeric material, plays important roles in many fields including catalysis, electrochemical devices, conducting materials and so on. As a class of metallosupramolecular polymers, metallosupramolecular polypseudorotaxane has attracted great attention not only because of its wide applications but also due to its facile synthesis which is by metal coordination between metal and macrocycle-based pseudorotaxane. The introducing of stimuli-responsive property into the metallosupramolecular polypseudorotaxane system will enrich their functionality. Herein, a triple stimuli-responsive metallosupramolecular polypseudorotaxane constructed by pillararene-based host–guest interaction and copper coordination. First, a new pH-sensitive pillar[5]­arene host (<b>H</b>) was synthesized. An azastilbenzene derivative, <i>trans</i>- 4,4′-vinylenedipyridine (<i><b>trans</b></i>-<b>G</b>) was chosen as the guest molecule to construct a [2]­pseudorotaxane based on <b>H</b> and <i><b>trans</b></i>-<b>G</b>. The [2]­pseudorotaxane displayed pH- and photo- dual stimuli-responsiveness. Then the [2]­pseudorotaxane was used to construct a pH-, photo- and cyanide-triple stimuli-responsive metallosupramolecular polypseudorotaxane based on Cu­(II) ion coordination

Dual-Responsive [2]Pseudorotaxane On the basis of a pH-Sensitive Pillar[5]arene and Its Application in the Fabrication of Metallosupramolecular Polypseudorotaxane

Metallosupramolecular polymer, an appealing polymeric material, plays important roles in many fields including catalysis, electrochemical devices, conducting materials and so on. As a class of metallosupramolecular polymers, metallosupramolecular polypseudorotaxane has attracted great attention not only because of its wide applications but also due to its facile synthesis which is by metal coordination between metal and macrocycle-based pseudorotaxane. The introducing of stimuli-responsive property into the metallosupramolecular polypseudorotaxane system will enrich their functionality. Herein, a triple stimuli-responsive metallosupramolecular polypseudorotaxane constructed by pillararene-based host–guest interaction and copper coordination. First, a new pH-sensitive pillar[5]­arene host (<b>H</b>) was synthesized. An azastilbenzene derivative, <i>trans</i>- 4,4′-vinylenedipyridine (<i><b>trans</b></i>-<b>G</b>) was chosen as the guest molecule to construct a [2]­pseudorotaxane based on <b>H</b> and <i><b>trans</b></i>-<b>G</b>. The [2]­pseudorotaxane displayed pH- and photo- dual stimuli-responsiveness. Then the [2]­pseudorotaxane was used to construct a pH-, photo- and cyanide-triple stimuli-responsive metallosupramolecular polypseudorotaxane based on Cu­(II) ion coordination

Dual-Responsive [2]Pseudorotaxane On the basis of a pH-Sensitive Pillar[5]arene and Its Application in the Fabrication of Metallosupramolecular Polypseudorotaxane

Metallosupramolecular polymer, an appealing polymeric material, plays important roles in many fields including catalysis, electrochemical devices, conducting materials and so on. As a class of metallosupramolecular polymers, metallosupramolecular polypseudorotaxane has attracted great attention not only because of its wide applications but also due to its facile synthesis which is by metal coordination between metal and macrocycle-based pseudorotaxane. The introducing of stimuli-responsive property into the metallosupramolecular polypseudorotaxane system will enrich their functionality. Herein, a triple stimuli-responsive metallosupramolecular polypseudorotaxane constructed by pillararene-based host–guest interaction and copper coordination. First, a new pH-sensitive pillar[5]­arene host (<b>H</b>) was synthesized. An azastilbenzene derivative, <i>trans</i>- 4,4′-vinylenedipyridine (<i><b>trans</b></i>-<b>G</b>) was chosen as the guest molecule to construct a [2]­pseudorotaxane based on <b>H</b> and <i><b>trans</b></i>-<b>G</b>. The [2]­pseudorotaxane displayed pH- and photo- dual stimuli-responsiveness. Then the [2]­pseudorotaxane was used to construct a pH-, photo- and cyanide-triple stimuli-responsive metallosupramolecular polypseudorotaxane based on Cu­(II) ion coordination

Cyclo[4]carbazole, an Iodide Anion Macrocyclic Receptor

A novel preorganized and rigid iodide anion macrocyclic receptor, cyclo[4]­carbazole (<b>Cy­[4]­C</b>), is reported here. The structure of <b>Cy­[4]­C</b> was confirmed by single-crystal X-ray analysis. The binding affinity of <b>Cy­[4]­C</b> for iodide anion was investigated by UV–vis and ¹H NMR spectroscopic techniques. The crystal structure of the complex between <b>Cy­[4]­C</b> and chloroform also provided evidence for the recognition ability of <b>Cy­[4]­C</b> toward iodide anion. Furthermore, the 1:1 complexation stoichiometry between <b>Cy­[4]­C</b> and iodide anion was confirmed by high-resolution mass spectrometry and molecular modeling

Cyclo[4]carbazole, an Iodide Anion Macrocyclic Receptor

A novel preorganized and rigid iodide anion macrocyclic receptor, cyclo[4]­carbazole (<b>Cy­[4]­C</b>), is reported here. The structure of <b>Cy­[4]­C</b> was confirmed by single-crystal X-ray analysis. The binding affinity of <b>Cy­[4]­C</b> for iodide anion was investigated by UV–vis and ¹H NMR spectroscopic techniques. The crystal structure of the complex between <b>Cy­[4]­C</b> and chloroform also provided evidence for the recognition ability of <b>Cy­[4]­C</b> toward iodide anion. Furthermore, the 1:1 complexation stoichiometry between <b>Cy­[4]­C</b> and iodide anion was confirmed by high-resolution mass spectrometry and molecular modeling