Coordination-Driven Poly[2]Pseudorotaxanes in Highly Polar Organic Solvent

Abstract

Self-assembly of polypseudorotaxanes in high-polar organic solvents is difficult due to remarkably weak interactions between macrocycles and axles. Reported here is a novel metal-coordinated poly[2]pseudorotaxane constructed by pillar[5]arene, 1,4-bis(4-pyridyl pyridinium)butane, and [PdCl 2 (PhCN) 2 ] in highly polar organic solvent of dimethyl sulfoxide (DMSO). Utilizing a combination of 1 H NMR, NOESY, DOSY, DLS, SEM, and viscosity measurements, the formation of polypseudorotaxane was shown to be dependent on the concentration of [2]pseudorotaxanes/[PdCl 2 (PhCN) 2 ] and temperature. Furthermore, a temperature-responsive supramolecular gel with reversibly gel-sol transformation was obtained via spontaneous assembly of the polypseudorotaxanes at high concentrations.

Acyl hydrazone‐based supramolecular polymer for ultrasensitive detection of Fe3+, Pd2+, H2PO4− and its application for Suzuki coupling reactions

“…[5][6][7] The specific process of supramolecular gel formation is through various weak interactions such as hydrogen bonding, π-π stacking, and van der Waals forces, which cause the stimulus molecules to form a kind of intermolecularly connected three-dimensional aggregates and trap the solvent molecules in it. [8][9][10] Based on the dynamic and reversible noncovalent interactions, supramolecular gels are valuable in a wide range of applications, including light trapping systems, drug delivery, cell culture, optoelectronic devices, self-healing materials, catalysis, and photosensing. [11][12][13][14][15] It is well known that many anions and cations are essential micronutrients in living organisms, and that ion levels are stable, excessive, or lack could seriously affect the health of organisms.…”

“…Supramolecular gels are semi‐solid viscoelastic materials formed by self‐aggregation of low molecular weight gelling agents (LMWGs) with immobilized solvents 5–7 . The specific process of supramolecular gel formation is through various weak interactions such as hydrogen bonding, π – π stacking, and van der Waals forces, which cause the stimulus molecules to form a kind of intermolecularly connected three‐dimensional aggregates and trap the solvent molecules in it 8–10 . Based on the dynamic and reversible non‐covalent interactions, supramolecular gels are valuable in a wide range of applications, including light trapping systems, drug delivery, cell culture, optoelectronic devices, self‐healing materials, catalysis, and photosensing 11–15 …”