Arene-based Host Research Articles

Selective wetting and transport of systemic pesticides on bionic stomatal surface regulated by host–guest interaction

Pesticide residues in the environment pose serious threats to ecosystem and human health, and how to achieve the selective transport and enrichment of specific pesticide residues through hydrophobic surface are still an important challenge. Herein, inspired by the “stomatal gating effect” of plant leaves, amino pillar[5]arene-based host–guest gating systems are introduced into artificial porous surfaces with hydrophobicity to fabricate bionic stomatal surfaces (AP5A porous surface), which is expected to modulate the interaction between pesticide and bionic surface through host–guest interaction to selective promote the wetting and transport of specific pesticide on the surface. Experimental and simulation results indicated the AP5A porous surface would selectively capture and adsorb the triclopyr pesticide by strong host–guest interaction to enhance pesticide wettability, and realized the host–guest interaction induced fast transport and enrichment of triclopyr (246.4 μM cm−2h−1) on the bionic stomatal surface. This work provides a new perspective that host–guest interaction between pesticides and solid surface as a gating switch to selective induce the systemic pesticides wetting and transport on bionic porous surface, which is believed to be useful in applications such as the enrichment and removal of pesticide residues from environment in the future.

A supramolecular oligo[2]rotaxane constructed by orthogonal platinum(II) metallacycle and pillar[5]arene-based host–guest interactions

Oligo[n]rotaxanes are one of the most extensively studied categories of mechanically bonded macromolecules. In this study, a supramolecular oligo[2]rotaxane is successfully constructed driven by platinum(II) metallacycle and pillar[5]arene-based host–guest interactions in an orthogonal way. The supramolecular oligo[2]rotaxane is further applied in fabricating a light harvesting system.

L-ribose specific recognition surface constructed by pillar[5]arene-based host–guest interaction

In living organisms, chiral molecules have specific chiral conformations that produce different physiological effects. Ribose is one of the components of RNA, which mainly plays a role in regulating biological activity. Inspired by the biological recognition of sugars, functional chiral surfaces for recognizing L-ribose through non-covalent interactions were constructed. In the strategy of this study, a functional chiral gold surface based on host-guest interactions was constructed through the assembly of the host molecule single-function alynyl pillar[5]arene(SAP5) and the guest molecule (S) -mandelate-violet (SMV). The association constant of SMV and SAP5 was calculated to be 2.95×104 M-1, with a binding ratio of 1:1. By impedance and contact angle detection, the constructed functional interface has good detection effect on L-ribose in the range of 1×10-7 M to1× 10-2 M. In addition, CV was disassembled from the aromatic cavity of pillar[5]arene after adding zinc powder and it can repeat five times with good recyclability, thus achieving the organic combination of interface recognition and intelligence.

Multistep sequence-controlled supramolecular polymerization by the combination of multiple self-assembly motifs

The precise sequence control of polymer chain is an important research topic of polymer chemistry. Although some methods such as iterative synthesis and supramolecular polymerization have been developed to fabricate sequence-controllable polymer, it is still a great challenge to consecutively prepare multiple supramolecular polymers with different sequence structures. In this work, through the reasonable utilization of assembly motifs, we integrated multiple host-guest recognitions and metal coordination interactions to prepare different sequence-controlled supramolecular polymers by a multistep assembly strategy. This research provides inspiration for the design and preparation of supramolecular polymers with different sequence structures.

Supramolecular aggregates constructed by pillar[5]arene-based host–guest interaction with aggregation-induced emission

Supramolecular aggregates with aggregation-induced emission were constructed by pillar[5]arene-based host–guest interaction.

Enhancing Mechanical Performance of a Polymer Material by Incorporating Pillar[5]arene-Based Host-Guest Interactions.

Polymer gels have been widely used in the field for tissue engineering, sensing, and drug delivery due to their excellent biocompatibility, hydrophilicity, and degradability. However, common polymer gels are easily deformed on account of their relatively weak mechanical properties, thereby hindering their application fields, as well as shortening their service life. The incorporation of reversible non-covalent bonds is capable of improving the mechanical properties of polymer gels. Thus, here, a poly(methyl methacrylate) polymer network was prepared by introducing host–guest interactions between pillar[5]arene and pyridine cation. Owing to the incorporated host–guest interactions, the modified polymer gels exhibited extraordinary mechanical properties according to the results of the tensile tests. In addition, the influence of the host–guest interaction on the mechanical properties of the gels was also proved by rheological experiments and swelling experiments.

A supramolecular polymer network constructed by pillar[5]arene-based host–guest interactions and its application in nitro explosive detection

A supramolecular polymer network constructed by pillar[5]arene-based host–guest interactions and its application in nitro explosive detection

Cross-linked supramolecular polymer networks constructed by pillar[5]arene-based host–guest recognition and coordination/oxidation of catechol

Two cross-linked supramolecular polymers are constructed by pillar[5]arene-based molecular recognition and mussel-inspired coordination/oxidation of catechol.

Recent Applications of Pillar[n]arene-Based Host-Guest Recognition in Chemosensing and Imaging.

Pillar[n]arene is a novel kind of synthetic supramolecular macrocyclic host characterized by its particular pillar-shaped structure consisting of an electron-rich cavity and two finely adjustable rims. Benefiting from its rigid structure, facile synthesis, ease of functionalization, and outstanding host-guest chemistry, pillar[n]arene shows great potential for diverse applications. Significantly, the host-guest recognition of pillar[n]arene provides a novel approach for chemosensing and imaging. Herein, this Review critically and comprehensively reviews the applications of pillar[n]arene-based host-guest recognition in chemosensing and imaging. The sensing and imaging mechanisms as well as the unique roles and advantages of pillar[n]arene-based host-guest recognition are summarized. In addition, preparations of hybrid materials based on pillar[n]arene and inorganic materials are also introduced comprehensively in the light of chemosensing and imaging. Finally, current challenges and perspectives on pillar[n]arene-based host-guest recognition in chemosensing and imaging are outlined.

A selective and stable vapochromic system constructed by pillar[5]arene-based host–guest interactions

The development of new strategies for the construction of highly selective and stable vapochromic system is still in great demand. Here, we present a highly selective and stable vapochromic system constructed by pillar[5]arene-based host–guest interactions between a pillar[5]arene (EtP5) and a phenazine derivative. The present material in this work showed specific selective responsiveness to chloroform vapor. The resultant dark orange solid sample was highly stable, which can maintain the color in air for at least two months at room temperature. Moreover, CHCl3 vapor responsive thin film and light-emitting diode (LED) was successfully prepared by coating the EtP5⊃1 complex on a glass sheet and a commercially available UV-LED. This work provided a new approach for the design and construction of selective and stable vapochromic systems with obvious color changes using pillar[5]arene-based host–guest interactions.

Chiral Nanochannels of Ordered Mesoporous Silica Constructed by a Pillar[5]arene-Based Host-Guest System.

The separation of racemic compounds by chiral nanochannels has attracted extensive attention. However, the fabrication of high-performance chiral nanochannels is still a challenge owing to the difficulty in magnifying the weak chiral interaction to macroscopic properties of materials. Herein, by introducing a l-alanine-pillar[5]arene host to achiral ordered mesoporous silica (OMS), chiral OMS nanochannels were fabricated, which exhibited excellent selectivity (ee value up to 90.2%) to separate racemic drugs with promising reusability and stability. Besides, it was identified that enantioselective separation took place through a molecular-recognition-adsorbed transport mechanism. This work highlights the great potential of chiral OMS nanochannels as a platform for enantioselective separation.

Formation of a lead chalcogenide quantum dot-based supramolecular polymer network via pillar[5]arene-based host–guest complexation

We presented the construction of a lead chalcogenide quantum dot-based fluorescent supramolecular polymer network driven by pillar[5]arene-based host–guest complexation.

Supramolecular nanoparticles constructed from pillar[5]arene-based host–guest complexation with enhanced aggregation-induced emission for imaging-guided drug delivery

Supramolecular nanoparticles with enhanced aggregation-induced emission are prepared by taking advantage of pillar[5]arene-based host–guest complexation, and are sophisticated nanocarriers for imaging-guided drug delivery.

Spreading of benquitrione droplets on superhydrophobic leaves through pillar[5]arene-based host-guest chemistry.

Spreading of agricultural sprays on plant surfaces is a significant task as it helps decrease pesticide usage and thereby reduces the risk of environmental pollution. Here, we report a method of increasing the spreading of herbicide benquitrione droplets on superhydrophobic surfaces through its selective dynamic self-assembly with amino pillar[5]arenes. Supramolecular interaction such as host-guest interaction was utilized for the complete diffusion of benquitrione over the hydrophobic plant surface. Furthermore, molecular dynamics simulations were used to verify that AP5A improved the spreading of benquitrione droplets on superhydrophobic interfaces. Moreover, complexation of benquitrione did not affect its biological activity. The present work provides a new method for improving the utilization rate of pesticides and reducing pesticide use.

Supramolecular polymer networks based on pillar[5]arene: synthesis, characterization and application in the Fenton reaction.

A new type of supramolecular polymeric material was constructed efficiently via orthogonal pillar[5]arene-based host-guest and hydrogen bond interactions. The supramolecular polymeric materials prove to be a good catalyst for the Fenton reaction in water.

Supramolecular peptide constructed by molecular Lego allowing programmable self-assembly for photodynamic therapy

Peptide self-assemblies with multiple nanostructures have great potentials in functional biomaterials, and yet the tedious and costly covalent peptide modification and the lack of facile controllability on self-assembly morphology retard the peptide-related exploration. Here we report a simple approach to fabricate a supramolecular peptide that shows programmable self-assembly with multiple morphologies and application in photodynamic therapy. Pillar[5]arene-based host−guest recognition is used to construct a supramolecular peptide, which simplify the peptide modification and promote the controllability of the self-assembly behavior. Due to the ERGDS sequences on the exterior surfaces and hydrophobic cores of self-assemblies, the nanoparticles formed from the supramolecular peptide are suitable vehicles to encapsulate a photosensitizer for photodynamic therapy. In vitro and in vivo studies demonstrate that the inherent targeting capability and supramolecular strategy greatly boost its photodynamic therapeutic efficiency. This supramolecular peptide holds promising potentials in precise cancer therapy and perspectives for the peptide modification.

CO2-Enhanced Bola-Type Supramolecular Amphiphile Constructed from Pillar[5]arene-Based Host–Guest Recognition

A CO2-enhanced bola-type supramolecular amphiphile was constructed from a water-soluble pillar[5]arene and a CO2-responsive bola-amphiphile. The gas-responsive self-assembly behavior of this supramolecular amphiphile and its application in controlled release were investigated.

A biomimetic chiral-driven ionic gate constructed by pillar[6]arene-based host\u2013guest systems

Inspired by glucose-sensitive ion channels, herein we describe a biomimetic glucose-enantiomer-driven ion gate via the introduction of the chiral pillar[6]arene-based host–guest systems into the artificial nanochannels. The chiral nanochannels show a high chiral-driven ionic gate for glucose enantiomers and can be switched “off” by d-glucose and be switched “on” by l-glucose. Remarkably, the chiral nanochannel also exhibited a good reversibility toward glucose enantiomers. Further research indicates that the switching behaviors differed due to the differences in binding strength between chiral pillar[6]arene and glucose enantiomers, which can lead to the different surface charge within nanochannel. Given these promising results, the studies of chiral-driven ion gates may not only give interesting insight for the research of biological and pathological processes caused by glucose-sensitive ion channels, but also help to understand the origin of the high stereoselectivity in life systems.

Construction of a Switchable Nanochannel for Protein Transport via a Pillar[5]arene-Based Host-Guest System.

Modulating protein selective translocation is a significant process, which has great potential for mimicking and understanding complex biological activities. As such, how to construct a nanochannel that can accomplish well gating protein transport is vital and challenge. Herein, inspired by nature, we presented a robust strategy to construct a switchable nanochannel by introducing a pH responsive binary host-guest system into a nanochannel. Benefiting from the novel design of the pillar[5]arene as gatekeeper, the functional nanochannel can well facilitate histone transport. Under pH regulation, the host-guest assembled nanochannel is capable of switching "on" and "off" to manipulate the histone translocation process. This study exemplifies the importance of molecular switch mediated protein transport in this process and provides a new theoretical model for biological research, which will open a new avenue for better understanding of some physiological and pathological behaviors.

Acid/Base-Controllable FRET and Self-Assembling Systems Fabricated by Rhodamine B Functionalized Pillar[5]arene-Based Host-Guest Recognition Motifs.

A novel supramolecular Föster resonance energy transfer (FRET) system was fabricated by utilizing rhodamine B (RB) functionalized pillar[5]arene (EtP5-RB) and cyano-modified boron dipyrromethene (BDP-CN) based on their host-guest recognition at 5.0 × 10-5 M, which could be turned "on" and "off" by adding trifluoroacetic acid (TFA) and triethylamine (TEA), respectively. At a higher concentration (1.0 × 10-4 M) in acetone, EtP5-RB self-assembled into vesicles while EtP5-RBH self-assembled into nanoribbons. After the addition of BDP-CN, both EtP5-RB⊃BDP-CN and EtP5-RBH⊃BDP-CN self-assembled into nanoparticles, which caused the fluorescence of the host-guest complexes to be quenched.