Pillararenes Trimer for Self-Assembly

Abstract

Pillararenes trimer with particularly designed structural geometry and excellent capacity of recognizing guest molecules is a very efficient and attractive building block for the fabrication of advanced self-assembled materials. Pillararenes trimers could be prepared via both covalent and noncovalent bonds. The classic organic synthesis reactions such as click reaction, palladium-catalyzed coupling reaction, amidation, esterification, and aminolysis are employed to build covalent bonds and integrate three pieces of pillararenes subunits together into the “star-shaped” trimers and linear foldamers. Alternatively, pillararenes trimers could also be assembled in the form of host-guest inclusions and mechanically interlocked molecules via noncovalent interactions, and during those procedures, pillararenes units contribute the cavity for recognizing guest molecules and act as a “wheel” subunit, respectively. By fully utilizing the driving forces such as host-guest interactions, charge transfer, hydrophobic, hydrogen bonding, and C–H…π and π–π stacking interactions, pillararenes trimers-based supramolecular self-assemblies provide a possibility in the construction of multi-dimensional materials such as vesicular and tubular aggregates, layered networks, as well as frameworks. Interestingly, those assembled materials exhibit interesting external stimuli responsiveness to e.g., variable concentrations, changed pH values, different temperature, as well as the addition/removal of competition guests and ions. Thus, they could further be used for diverse applications such as detection, sorption, and separation of significant multi-analytes including metal cations, anions, and amino acids.

Towards nanomaterials with tubular pores: synthesis and self-assembly of bis-pillar[5]arene

“…The presence of cross-peaks of the nuclear Overhauser effect between the protons of the piperazide and aryl fragments, between the protons of the piperazide and oxymethylene fragments, as well as between the protons of the aryl fragments of macrocyclic units clearly indicates a spatially close arrangement of macrocyclic fragments relative to each other. This fact confirms the expected tubular shape of bis-pillar [5] The presence of amide fragments in the structure of the macrocycle, as a rule, promotes the emergence of self-association processes [18]. It should be noted that in the case of the formation of associates by bis-pillar [5]arene 3, the tubular shape of the formed pores is obviously retained.…”

Novel magnetic silk fibroin scaffolds with delayed degradation for potential long-distance vascular repair

“…The weakly acidic liquid environment weakened the hydrogen bonding between MNPs and SFC, replacing a part of the hydrogen ions, resulting in more MNPs being released. The release of MNPs in DMEM was more than that in PBS, which might be because the chemical groups exposed by glucose, glutamine, and sodium pyruvate in DMEM would slightly replace a part of the hydrogen ions, resulting in more release than PBS [ 62 , 63 ]. The released MNPs were also easily phagocytized by macrophages.…”

Pillararene-functionalised graphene nanomaterials

“…(4) Concerning the expansion of the application elds, more functional groups could be introduced into the hybrid composites via either the modication of pillararene derivatives or the decoration of the outer surface of graphene materials. The introduction of various functional moieties 40,41 could allow pillararene-functionalised graphene materials to, for example, have better water dispersity and solubility, which promote the materials to have better biocompatibility and lower cytotoxicity, leading to the expansion of application to more aspects of biomedicines such as diagnosis and combined therapy. 42…”