Arene-based Host Guest Interactions Research Articles

A Temperature-Sensitive Fluorescent Supramolecular Polymer Constructed by Discrete Platinum(II) Metallacycle and Pillar[5]arene-Based Host-Guest Interactions.

The application of thermosensitive fluorescent supramolecular polymers in advanced optical materials, chemical sensors, artificial optical devices, and external stimulus responses remains underdeveloped. In this study, we introduced a novel method for constructing a mechanically interlocked fluorescent supramolecular polymer utilizing host-guest interactions, including C-H···π interactions and π-π stacking. This polymer exhibits outstanding temperature-sensitive fluorescence properties and is environmentally friendly due to its recyclability. Leveraging the polymer's fluorescence response at critical temperature ranges, we developed a high-temperature warning device. This device utilizes the temperature-sensitive fluorescence characteristic of the polymer to indicate dangerous temperature levels, thereby demonstrating its potential in practical safety applications.

Supramolecular Sequential Light-Harvesting Systems for Constructing White LED Device and Latent Fingerprint Imaging.

The fabrication of supramolecular light-harvesting systems (LHS) with sequential energy transfer is of significance in utilizing light energy. In this study, we report the non-covalent self-assembly of a sequential LHS by pillar[5]arene-based host-guest interaction in water and its applications in white light-emitting diode (LED) device and latent fingerprint imaging. The host-guest complex WP5 G self-assembles into nanoparticles in water and shows enhanced aggregation-induced emission (AIE) effect. The nanoparticles can be further used to construct sequential LHS with fluorescent dyes 4,7-di(2-thienyl)-benzo[2,1,3]thiadiazole (DBT) and sulforhodamine 101 (SR101). Impressively, the system shows white-light emission when the molar ratio of WP5 G/DBT/SR101 is 1100/2/16. The material can be coated on a LED bulb to achieve white-light emission. In addition, the sequential LHS exhibit multicolor fluorescence including red emission, which have been successfully applied to high-resolution imaging of latent fingerprints. Therefore, we demonstrated a general strategy for the construction of sequential LHS in water based on macrocyclic host-guest interaction and explored its multi-functional applications in white-light LED device and imaging of latent fingerprints, which will promote future development and application of supramolecular LHSs.

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.

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.

Tumor microenvironment responsive polypeptide-based supramolecular nanoprodrugs for combination therapy

Tumor microenvironment responsive nanomedicine has drawn considerable attention for combination therapy, but still remains a significant challenge for less side effects and enhanced anti-tumor efficiency. Herein, we develop a pH/ROS dual-responsive supramolecular polypeptide nanoprodrug (PFW-DOX/GOD) by using pillar[5]arene-based host-guest strategy for combined glucose degradation, chemodynamic therapy (CDT), and chemotherapy (CT). The PFW-DOX/GOD consists of a pH-responsive ferrocene/pillar[5]arene-containing polypeptide, a ROS-responsive polyprodrug, and encapsulated glucose oxidase (GOD). Upon into intracellular acidic environment, PFW-DOX/GOD exhibits rapid pH-triggered disassembly behavior. Simultaneously, the released GOD can catalyze intratumoral glucose into massive H2O2, which are further converted into highly toxic hydroxyl radicals (•OH) by the catalysis of ferrocene via the Fenton reaction. Thereafter, induced by the ROS-responsive cleavage of thioketal linkage, the conjugated DOX prodrug was released and activated. The combined glucose degradation, chemodynamic therapy (CDT), and chemotherapy (CT) of PFW-DOX/GOD present anti-tumor effect with 96% of tumor inhibitory rate (TIR). Therefore, such tumor microenvironment-responsive supramolecular polypeptide nanoprodrugs represent a potential candidate for combination therapy with minimal side effects. Statement of significanceIn this work, a tumor microenvironment-responsive supramolecular polypeptide nanoprodrug (PFW-DOX/GOD) was prepared via pillar[5]arene-based host-guest interactions, and presented low side effects and high tumor accumulation owing to the diameters of about 200 nm and surface PEG segment. After pH-responsive release of GOD in the intracellular acidic environment, the cascade catalytic reactions including GOD-catalyzed degradation of intratumoral glucose and Fenton reaction, effectively happened to generate •OH for chemodynamic therapy (CDT), which subsequently induced the cleavage of thioketal linkage to activate free DOX for chemotherapy (CT). Collectively, this supramolecular polypeptide nanoprodrugs provide a promising strategy for combination therapy with synergetic anti-tumor effect.

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

Enhancing the Stability and Photothermal Conversion Efficiency of ICG by Pillar[5]arene-Based Host-Guest Interaction.

Indocyanine green (ICG) is a classical near-infrared (NIR) photothermal reagent that can be employed in clinical medical detection. Under neutral conditions, ICG can adsorb NIR light effectively for photothermal (PTT) and photodynamic (PDT) therapy. However, ICG is easily degraded in weak acid environments, which seriously restricts its application. In this work, a cationic water-soluble pillar[5]arene (WP5) was selected as the stabilizing agent for ICG. Thanks to the host-guest interaction between WP5 and alkyl sulfonate, the stability and the photothermal conversion efficiency of ICG increased remarkably upon addition of WP5 as investigated by UV-vis spectrum and photothermal studies. Furthermore, an in vitro study showed higher efficiency of WP5&ICG in killing cancer cells in a shorter treatment time than the free ICG. Hence, it is hopeful that WP5 can be a new type of supramolecular host in enhancing the stability and photothermal conversion efficiency of photosensitizers.

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.

Pillar[5]arene-based supramolecular assemblies with two-step sequential fluorescence enhancement for mitochondria-targeted cell imaging

Two-step sequential fluorescence emission enhanced supramolecular nanoparticles are constructed from pillar[5]arene based host–guest interaction and a linear amphiphile. These supramolecular nanoparticles can be applied in mitochondria-targeted live cell imaging.

Reversible surface activity and self-assembly behavior and transformation of amphiphilic ionic liquids in water induced by a pillar[5]arene-based host-guest interaction

In this paper, we aimed to develop a reversible and effective method to control the surface activity and self-assembled morphology of amphiphilic imidazolium-type ionic liquids (G) in water. For this purpose, a series of pillar[5]arene/imidazolium supramolecular complexes were designed and prepared. Before the formation of the host-guest complex, the surface activity of G7 worked well, and foams could be generated easily. However, after the addition of water-soluble pillar[5]arene (WP5), the rigid WP5 platform caused steric hindrance that prevented the hydrophobic chains on G7 from getting close to each other, inducing the change in surface activity. On the other hand, because paraquat (PQ) has a larger association constant with WP5 than G7, the surface activity of the solution can be recovered after the addition of PQ. TEM confirmed that self-assembled morphologies of this reversible system transformed from nanoparticles to nanosheets then to nanoparticles. It is anticipated that this supramolecular method for controlling the surface activity of amphiphiles in a reversible way may find application in fields where fast foaming and defoaming are needed.

Visible Light-Induced Supra-Amphiphilic Switch Leads to Transition from Supramolecular Nanosphere to Nanovesicle Activated by Pillar[5]arene-Based Host-Guest Interaction.

A photoresponsive host-guest supramolecular complex (WP5⊃G) constructed by water-soluble pillar[5]arene (WP5) and spiropyran derivative (G) is presented. The spontaneous isomerization of G from spiropyran (SP) form to ring-opened merocyanine (MC) form happens either alone or in WP5⊃G in aqueous media. Irradiated by visible light, G can be converted into SP form completely and the hydrophilicity will be changed. G and WP5⊃G are both verified to self-assemble into nanospheres. Upon exposure to visible light, WP5⊃G reassemble into nanovesicles due to the change of supra-amphiphilicity, while G alone does not have this transition. Obviously, WP5 takes the key role that activates the photoinduced morphological transition.

Hybrid supramolecular materials constructed from pillar[5]arene based host–guest interactions with photo and redox tunable properties

Monocarboxylate functionalized pillar[5]arene 1 with excellent solubility in organic solvent was prepared. It could be abosorpted on the surface of gold nanorod spontaneously. Then, hybrid supramolecular materials were constructed from 1 stabilized gold nanorods and a linear dinitriles 2 driven by host–guest interaction. Interestingly, the hybrid supramolecular materials show dynamic near-infrared (NIR) and redox dual-responsive reversible properties. 1H nuclear magnetic resonance (NMR) spectra, transmission electron microscopy (TEM), scanning electron microscopy (SEM), optical microscopy, and specific viscosity were used to characterize the obtained materials and the reversible behavior under external stimuli. We suggest that this NIR and redox dual-responsiveness properties would be useful in preparation other smart materials and have potential in vivo applications.

Formation of Linear Side‐Chain Polypseudorotaxane with Supramolecular Polymer Backbone through Neutral Halogen Bonds and Pillar[5]arene‐Based Host–Guest Interactions

Linear side-chain polypseudorotaxane with supramolecular polymer backbone was assembled by neutral halogen bonds (XB) and pillar[5]arene-based host-guest interactions in solution and in the solid state. The formation of the halogen-bonded supramolecular polymer backbone and side-chain polypseudorotaxane in solution was characterized by 1 H NMR spectroscopy, diffusion ordered NMR spectroscopy and scanning electron microscopy experiments. Furthermore, the solid-state structures of these two highly organized supramolecular architectures were provided by single-crystal X-ray analysis.

Artificial light-harvesting supramolecular polymeric nanoparticles formed by pillar[5]arene-based host-guest interaction.

Artificial light-harvesting nanoparticles were prepared from supramolecular polymers comprised of pillar[5]arene with anthracene-derived donors and acceptors through host-guest interactions. The resulting water-dispersible nanoparticles displayed efficient energy transfer and excellent light harvesting ability in part because the steric bulk of pillar[5]arene suppressed the self-quenching of the chromophores.

Temperature-Sensitive Artificial Channels through Pillar[5]arene-based Host-Guest Interactions.

In living systems, temperature-sensitive ion channels play a vital role in numerous cellular processes and can be controlled by biological ion channels in response to specific temperature stimuli. Facile pillar[5]arene-based host-guest interactions are introduced into a nanochannel pattern for constructing a temperature-sensitive artificial channel. Ion transport was switched from cations to anions by controlling the extent of the host bound to the guest with temperature stimuli. This efect is mainly due to the changing of the inner surface charge and wettability of the nanochannel during the process. This study paves a new way for better understanding the mechanism of temperature-sensitive properties and shows great promise for biomedical research.

Correction: The macroscopic wettable surface: fabricated by calix[4]arene-based host-guest interaction and chiral discrimination of glucose.

Correction for 'The macroscopic wettable surface: fabricated by calix[4]arene-based host-guest interaction and chiral discrimination of glucose' by Yue Sun et al., Chem. Commun., 2016, 52, 14416-14418.

In situ supramolecular polymerization promoted by the marriage of dynamic covalent bonding and pillar[5]arene-based host-guest interaction.

In situ fabrication of a temperature and pH dual-responsive linear supramolecular polymer through the marriage of dynamic covalent bonding and pillar[5]arene-based host-guest interaction was investigated.

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 polymer network gel was fabricated by orthogonal Ag-coordination and pillar[5]arene-based host–guest interactions.