Liqing Shangguan

A supramolecular polymer network gel with stimuli-responsiveness constructed by orthogonal metal ion coordination and pillar[5]arene-based host–guest recognition

A novel external stimuli-responsive supramolecular metallogel was fabricated by orthogonal Ag-coordination and pillar[5]arene-based host–guest molecular recognition.

Dual-responsive self-assembly of a bola-type supra-amphiphile constructed from a new pillar[6]arene-based recognition motif in water and its application in controlled release

Dual-responsive self-assembly of a bola-type supra-amphiphile was constructed from a new recognition motif based on a water-soluble pillar[6]arene and an azobenzene-containing guest in water and its application in controlled release was studied.

A pillar[5]arene-based 3D network polymer for rapid removal of organic micropollutants from water

Organic micropollutants are posing great challenges to global water resources, especially for non-biodegradable synthetic chemicals. In this study, a carboxyl-derived pillar[5]arene (P5) and p-phenylenediamine (PPD) were crosslinked to produce a 3D network polymer, P5-P, for the adsorption and removal of organic micropollutants from water. This 3D network polymer sequesters a variety of organic micropollutants in water with rapid adsorption rates and large uptake amounts, much greater than those of conventional activated carbon. Especially, this polymer demonstrates superior adsorption performance for fluorescein sodium and methyl orange and it can be fully regenerated multiple times by a mild washing procedure. The structure of this 3D network polymer and its adsorption mechanisms have been confirmed by solid-state nuclear magnetic resonance (SSNMR). The excellent pollutant removal ability demonstrates the promise of the pillar[5]arene-based 3D network polymer for rapid waste-water treatment.

Pillar[5]arene-based chiral 3D polymer network for heterogeneous asymmetric catalysis

A novel chiral 3D polymer network with evenly dispersed catalytic sites, good heterogeneous asymmetric catalytic ability and recyclability was easily constructed by pillar[5]arene and (R,R)-tetraaryl-1,3-dioxolane-4,5-dimethanol derivatives.

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

In this work, a Pd2 L4 metallacage 2•([BF4 ]- )4 with four pillar[5]arene units is first prepared and characterized by 1D multinuclear NMR (1 H, 11 B, and 19 F NMR), 2D 1 H-1 H correlation spectra, 1 H-13 C heteronuclear single quantum coherence, and diffusion-ordered NMR spectroscopy, and electrospray ionization time-of-flight mass spectrometry. By the introduction of a ditopic guest molecule 3 into a chloroform solution of 2•([BF4 ]- )4 , a supramolecular polymer network gel is successfully constructed based on the metal coordination interactions and host-guest recognition between the pillar[5]arene units of 2•([BF4 ]- )4 and neutral ditopic guest molecule 3. The temperature and pH responsivenesses of the supramolecular gel are studied, which are further employed for the controlled release of different cargos. As a demonstration, emodin and methylene blue are trapped in the cavities of the metallacage and in the pores of the supramolecular gel, respectively. Methylene blue is first released along with the gel-sol transition while emodin is then released by the further addition of acid to destroy the metallacage. This study explores the use of metallacage-cored supramolecular network gels for sequential controlled release and contributes to the development of smart and adaptive materials.