Supramolecular Pseudorotaxane Polymers from Biscryptands and Bisparaquats

Abstract

Five new bis(dibenzo-30-crown-10-based cryptand)s were synthesized, two of which (16 and 17) had long (12-atom), flexible spacers that led to cooperative complexation of dibenzyl paraquat TFSI ( K = 4.36 × 10 M for 17•2b). Self-assembly of 16 and 17 with bisparaquats with similar spacers (18, 21, and 23) led to high molecular weight supramolecular pseudorotaxane polymers in solution. Continuous, flexible fibers were drawn from concentrated solutions. 17 with C-linked bisparaquat 23 in dichloromethane (DCM) produced a log-log viscosity vs concentration plot with a limiting slope of 3.55, confirming high molecular weight; at 37 mM, the degree of polymerization was estimated to be 126 and M = 407 kDa. These are the first truly polymeric pseudorotaxane-type AA/BB supramolecular polymers.

Construction of Metallacage‐Cored Supramolecular Gel by Hierarchical Self‐Assembly of Metal Coordination and Pillar[5]arene‐Based Host−Guest Recognition

“…Pillar[ n ]arenes, as a new type of macrocyclic hosts after cyclodextrins, crown ethers, calixarenes, and cucurbiturils, have received increasing attention since they were first reported in 2008 . Their pillar‐shaped structures, ease of functionalization and extensive host−guest recognition capabilities especially for neutral guests make them widely applied in supramolecular polymers, drug delivery, sensors, etc .…”

Removal of Organic Micropollutants from Water by Macrocycle‐Containing Covalent Polymer Networks

“…Common macrocycles that have been incorporated into polymeric networks for water purification include cyclodextrins (CDs), [14–20] calixarenes, [21–26] pillararenes, [27–32] resorcinarenes, [33–37] and imidazolium macrocycles [38–41] . On the other hand, other typical macrocycles, including crown ethers, [42–44] cucurbiturils (CBs), [45–47] and calix[4]pyrroles (C4Ps,) [48–50] have not yet been widely used in this context. In this Review, we highlight recent advances (from 2016 to mid‐2020) in the removal of organic micropollutants from water by various macrocycle‐containing covalent polymer networks.…”

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

“…Recent advances in polyrotaxanes and polypseudorotaxanes have exposed their proposed applications toward the development of molecular machines, self‐healing polymers, responsive materials, and sensors . To date, a variety of polypseudorotaxanes and polyrotaxanes have been successfully fabricated based on molecular recognition by various macrocycles such as crown‐ethers, cryptands, cyclodextrins, and cucurbit[n]urils . Pillar[n]arenes have evolved as versatile macrocyclic hosts in supramolecular chemistry since their first synthesis by Ogoshi and coworkers .…”

“…20 To date, a variety of polypseudorotaxanes and polyrotaxanes have been successfully fabricated based on molecular recognition by various macrocycles such as crown-ethers, cryptands, cyclodextrins, and cucurbit[n] urils. [19][20][21][22][23] Pillar[n]arenes have evolved as versatile macrocyclic hosts in supramolecular chemistry since their first synthesis by Ogoshi and coworkers. 24 Due to their ease of preparation as well as functionalization, rigid architecture, and versatile properties, pillar[n]arenes have been explored over the past decade as promising macrocyclic hosts for the construction of supramolecular polymers upon self-assembly from small molecules.…”