Arene-based Host Guest Research Articles

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.

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.

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.

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.

A multi-responsive cross-linked supramolecular polymer network constructed by mussel yield coordination interaction and pillar[5]arene-based host-guest complexation.

Here a novel cross-linked supramolecular polymer network with thermal, pH, and H2S responsiveness was prepared inspired by mussel yield catechol-Fe3+ coordination and pillar[5]arene-based host-guest interactions.

Supramolecular Hybrid Material Constructed from Graphene Oxide and Pillar[6]arene-Based Host-Guest Complex as a Ultrasound and Photoacoustic Signals Nanoamplifier.

Photoacoustic imaging combines the merits of ultrasound imaging and optical imaging that allows a fascinating imaging paradigm with deeper tissue penetration than optical imaging and higher spatial resolution than ultrasound imaging. Herein, we develop a supramolecular hybrid material composed of graphene oxide (GO) and a pillar[6]arene-based host-guest complex (CP6⊃PyN), which can be used as a ultrasound (US) and photoacoustic (PA) signal nanoamplifier. Triggered by the near-infrared (NIR) light mediated photothermal effect, CO2 nanobubbles are generated on the surface of GO@CP6⊃PyN due to the decomposition of bicarbonate counterions, thus strongly amplifying its US and PA performances. Our study, for the first time, demonstrates enhanced US and PA activity in supramolecular hybrid material on the basis of host-guest chemistry as a photoacoustic nanoplatform.

A supramolecular hyperbranched polymer with multi-responsiveness constructed by pillar[5]arene-based host–guest recognition and its application in the breath figure method

A supramolecular gel with multi-responsiveness or honeycomb-patterned film was constructed by pillararene-based host–guest recognition.

Solid-state self-inclusion complexation behaviour of a pillar[5]arene-based host–guest conjugate

A host–guest conjugate consisting of a pillar[5]arene and an ethylene moiety containing a triazole group at one end and a perfluorooctyl group at the other end displayed unusual real-time scale solid-state self-inclusion complexation behaviour.

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.

Three-dimensional supramolecular polymerization based on pillar[n]arenes (n = 5, 6) and halogen bonding interactions.

Herein we demonstrate that three dimensional supramolecular polymerization networks were constructed both in solution and in the solid state by the combination of pillar[5,6]arene-based host-guest complexes and 1,4-diiodotetrafluorobenzene involving halogen bonding systems.

Efficient enhancement of fluorescence emission via TPE functionalized cationic pillar[5]arene-based host–guest recognition-mediated supramolecular self-assembly

A tetraphenylethene (TPE) functionalized cationic pillar[5]arene (CWP5-TPE) was successfully synthesized, and the intramolecular rotation of the TPE motif was restricted via cationic pillar[5]arene-based host–guest recognition-mediated supramolecular self-assembly in water, resulting in the efficient enhancement of fluorescence emission based on the aggregation induced emission (AIE) mechanism. CWP5-TPE self-assembled into nanoribbons while the host–guest inclusion complex formed into supramolecular amphiphile nanoparticles in water.

A triply-responsive supramolecular amphiphile fabricated by a thermal-responsive pillar[5]arene-based host–guest recognition motif

A novel molecular recognition motif was built between a neutral water soluble pillar[5]arene and decyltrimethylammonium bromide in water. Its thermal-controlled complexation with G1 in water was investigated. Furthermore, based on this new thermal responsive host–guest recognition motif, we further constructed a supramolecular amphiphile between this pillar[5]arene and a trimethylammonium bromide derivative containing an azobenzene group at the other end. This supramolecular amphiphile showed triply-responsiveness, that is, thermal responsiveness of the host–guest complex, photo-responsiveness of the azobenzene group and chemical-responsiveness by adding β-CD.

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.

Enhancing the solubility and bioactivity of anticancer drug tamoxifen by water-soluble pillar[6]arene-based host-guest complexation.

A water-soluble pillar[6]arene functions as a solubilizing agent to enhance the solubility and bioactivity of poorly water-soluble anticancer drug tamoxifen by host-guest complexation between it and tamoxifen.

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.

Two novel supramolecular metallogels constructed by platinum(ii) coordination and pillar[5]arene-based host–guest interactions

Two multi-responsive supramolecular metallogels were constructed by coordination-driven self-assembly, host–guest interaction and supramolecular polymerization.

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.

Control on the photo-responsive assembly of a stilbene-containing amphiphile by using pillar[5]arene-based host-guest interactions.

A supra-amphiphilic system with a tunable supra-amphiphilic type and self-assembled morphology was constructed and controlled via light and host-guest interactions based on a water-soluble pillar[5]arene and a stiff-stilbene.