Construction of anion‐responsive crosslinked polypseudorotaxane based on molecular recognition of pillar[5]arene

Abstract

On page 1373, scientists from The Dow Chemical Company discuss their finding that surfactant-free acrylic emulsion polymerization in the presence of a self-assembled polyurea macromer (PUM) nanodispersion resulted in hybrid acrylic-polyurea particles. This hybrid emulsion formed films resembling a composite closed cell foam structure. The cover art shows the TEM of a representative film at two different magnifications. The interfacial volume between particles is illustrated to show the hypothesized polymer interaction between the acrylic phase and polyurea phase. Some intermixing at this phase boundary is expected to enable film formation, given that the PUM is not capable of forming a film on its own.

Functional Supramolecular Polymeric Networks: The Marriage of Covalent Polymers and Macrocycle-Based Host–Guest Interactions

“…Arunachalam and co-workers reported an anion-responsive SPN based on the pillar[5]­arene/pyridinium salt host–guest recognition motif . In this case, the pillar[5]­arene pendent polymer 189 was first synthesized from a pillar[5]­arene-based oxanorbornene unit by means of a ring-opening metathesis polymerization using Grubbs’ first generation catalyst (Figure ).…”

“…Also shown in cartoon representation is the SPN 191 obtained as the result of host–guest driven self-assembly and its response to anions. Reproduced with permission from ref . Copyright 2019 John Wiley and Sons.…”

Pillararene-Containing Polymers with Tunable Conductivity Based on Host–Guest Complexations

“…15 Nevertheless, wellstructured homopolymers and block copolymers containing pillararenes have been rarely reported because they may require a complicated synthesis. 16 For example, Wang prepared a pillar [5]arene-containing polymer by a Cu-catalyzed homocoupling reaction of a pillar [5]arene-based monomer after stirring for 7 days, and the degree of polymerization was only 8. 17 Subsequently, they tried to synthesize pillar [6]arenecontaining homopolymer by free radical polymerization, but failed due to the bulky steric hindrance side group.…”

“…In order to develop the potential of polymers containing pillararenes, our group reported copolymers with pendant pillararenes, which formed a multiresponsive supramolecular gel . Nevertheless, well-structured homopolymers and block copolymers containing pillararenes have been rarely reported because they may require a complicated synthesis . For example, Wang prepared a pillar[5]­arene-containing polymer by a Cu-catalyzed homocoupling reaction of a pillar[5]­arene-based monomer after stirring for 7 days, and the degree of polymerization was only 8 .…”

Anion-Responsive Pseudo[3]rotaxane from a Difunctionalized Pillar[4]arene[1]quinone and a Bis-Imidazolium Cation

“…In recent years, pillar­[ n ]­arenes have attracted much attention and proved themselves as versatile receptors in host–guest chemistry. − Structural studies on complex molecular assemblies would give insight into the development of functional materials. Pseudo[3]­rotaxane assemblies are more important as a cross-linking unit in the fabrication of supramolecular polymer networks and gels . Though numerous works have been reported in the literature demonstrating the synthesis of pillar­[ n ]­arene based pseudo[2]­rotaxanes, − high order assemblies including pseudo[3]­rotaxanes − are still rare.…”