π-π stacking interactions: Non-negligible forces for stabilizing porous supramolecular frameworks

Abstract

Revealing the contribution of - stacking interactions in supramolecular assembly is important for understanding the intrinsic nature of molecular assembly fundamentally. However, because they are much weaker than covalent bonds, - stacking interactions are usually ignored in the construction of porous materials. Obtaining stable porous materials that are only dependent on - stacking interactions, despite being very challenging, could address this concern. Here, we present a porous supramolecular framework (-1) stabilized only by intermolecular - stacking interactions. -1 shows good thermal and chemical stability not only in various organic solvents but also in aqueous solution in a broad pH range. Furthermore, featuring one-dimensional channels with dangling thiolate groups, -1 exhibits excellent Hg 2+ removal performance, with adsorption capacity as high as 786.67 mg g −1 and an adsorption ratio as high as 99.998%. In addition, -1 also shows high adsorption selectivity to Hg 2+ in the presence of a series of interfering ions.

Noncovalent π-stacked robust topological organic framework

“…However, controlled large-scale assembly is one of the more crucial aspects for effective charge transport in organic semiconductors and is difficult to achieve. The emergence of organic frameworks (OFs) has opened an avenue for predicting and controlling the molecular assembly, especially in covalent OFs (COFs) (14)(15)(16)(17). The final COF topology can now be determined based on the relative geometries of raw materials.…”

An Ultrastable Crystalline Acylhydrazone‐Linked Covalent Organic Framework for Efficient Removal of Organic Micropollutants from Water

“…Previous studies have shown that π-π stacking interactions predominate for the structural stability in porous materials such as metal organic frameworks (MOFs) and hydrogen-bonded organic framework (HOFs). [32][33][34] In comparison with COF-HNU7, two types of π-π stacking modes were observed in the large πconjugated system of COF-HNU6 (Figure 5b), including the π-π interactions between building blocks along the c-axis (interlayer distance 3.479 Å) and the strong π-π interactions between azobenzene rings along the c-axis (interlayer distance 3.479 Å). It was found that the interlayer interaction energy dramatically increased from 60.88 kcal mol À 1 for COF-HNU7 to 91.4 kcal mol À 1 for COF-HNU6 due to the incorporating azobenzene groups (Table S1).…”

Molecular Docking Study of the Binding Interaction of Hydroxychloroquine, Dexamethasone and Other Anti-Inflammatory Drugs with SARS-CoV-2 Protease and SARS-CoV-2 Spikes Glycoprotein

“…The interactions in Table 2 consisted of two hydrophilic hydrogen bonding with two ASN-343 and one strong hydrophobic π-π stacking interaction with TRP-436 amino acid. The π-π stacking interaction can significantly increase ligand-protein stability [60] which would mean the structural and functional properties of meloxicam would remain unaltered during drug delivery thus increasing therapeutic efficacy [61]. The interactions of meloxicam were weaker with the 6LU7 protein which consisted of one hydrogen hydrophilic interaction with ASP-153 and one hydrophobic pi-H interaction with TYR-154 amino acid.…”