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On–off switching and molecular logic in fluorescent molecules are associated with what chemical inputs can do to the structure and dynamics of these molecules. Herein, we report the structure of a naphthalene derivative, the fashion of its binding to β‐cyclodextrin and DNA, and the operation of logic possible using protons, cyclodextrin, and DNA as chemical inputs. The compound crystallizes out in a keto‐amine form, with intramolecular N−H⋅⋅⋅O bonding. It shows stepwise formation of 1:1 and 1:2 inclusion complexes with β‐cyclodextrin. The aminopentenone substituents are encapsulated by β‐cyclodextrin, leaving out the naphthalene rings free. The binding constant of the β‐cyclodextrin complex is 512 m−1. The pKa value of the guest molecule is not greatly affected by the complexation. Dual input logic operations, based on various chemical inputs, lead to the possibility of several molecular logic gates, namely NOR, XOR, NAND, and Buffer. Such chemical inputs on the naphthalene derivative are examples of how variable signal outputs based on binding can be derived, which, in turn, are dependent on the size and shape of the molecule. Lifting logic from molecules: Compounds or complexes that have different properties depending on specific inputs, e.g. pH, can be used to generate Boolean logic functions. Naphthalene β‐diketone derivatives bind to DNA and β‐cyclodextrin, where aminopentenone substituents are encapsulated inside the β‐cyclodextrin cavity. The resulting compound displays NOR, XOR, NAND, and Buffer logic operations based on proton, cyclodextrin, and DNA as chemical inputs.

Herein, we have designed and fabricated a simple and efficient supramolecular self-assembled nanosystem based on host–guest interactions between water-soluble tetraphenylethylene-embedded pillar[5]arene ( m -TPEWP5 ) and ammonium benzoyl-ʟ-alaninate ( G ) in an aqueous medium. The obtained assembly of m -TPEWP5 and G showed aggregation-induced emission (AIE) via the blocking of intramolecular phenyl-ring rotations and functioned as an ideal donor. After the loading of eosin Y ( EsY ) as acceptor on the surface of the assembly of m -TPEWP5 and G , the worm-like nanostructures changed into nanorods, which facilitates a Förster resonance energy transfer (FRET) from the m -TPEWP5 and G assembled donor to the EsY acceptor present in the nanorod assembly. The system comprising m -TPEWP5 , G and EsY displayed moderate FRET efficiency (31%) at a 2:1 molar ratio of donor-to-acceptor. Moreover, the obtained supramolecular nanorod assembly could act as a nanoreactor mimicking natural photosynthesis and exhibited a high catalytic efficiency for the photocatalytic dehalogenation reaction of various bromoketone derivatives with good yields in short reaction time in water.

Understanding the host‐guest interactions for thermally activated delayed fluorescence (TADF) emitters is critical because the interactions between the host matrices and TADF emitters enable precise control on the optoelectronic performance, whereas technologically manipulating the singlet and triplet excitons by using different kinds of host‐guest interactions remains elusive. Here, we report a comprehensive picture that rationalizes host‐guest interaction‐modulated exciton recombination by using time‐resolved spectroscopy. We found that the early‐time relaxation is accelerated in polar polymer because dipole‐dipole interaction facilitates the stabilization of the 1CT state. However, an opposite trend is observed in longer delay time, and faster decay in the less polar polymer is ascribed to the π‐π interaction that plays the dominant role in the later stage of the excited state. Our findings highlight the technological engineering singlet and triplet excitons using different kinds of host‐guest interactions based on their electronic characteristics. The previous work about host‐guest interactions of TADF materials mainly focus on the origin of solid‐state solvation and the temporal behavior of TADF emitters in various hosts, which are all based on the singlet state with CT character. Within this context, technologically manipulating the singlet and triplet excitons by using different kinds of host‐guest interactions remains elusive. Here, we report a comprehensive picture that rationalizes host‐guest interaction‐modulated exciton recombination by using time‐resolved spectroscopy. The present investigation provides valuable insights for manipulating the TADF device in glassy matrices by introducing codopants with polar side chains or conjugate π‐planar structures.

A series of new π ‐conjugated macrocycles ( AzoM‐n‐ E , n = 1–3) incorporating azobenzene units have been synthesized by a facile strategy in one‐pot reaction. The resultant azobenzene‐embedded macrocycles feature intrinsic photoresponsive behaviors and intriguing supramolecular assembling properties. The smallest macrocycle AzoM‐1‐ E with a rigid planar conjugated backbone structure is used to prepare the single crystal transistors, showing reversible optical tunability. The moderate size macrocycle AzoM‐2‐ E assembles into a dimer in the form of interpenetration through π‐π stacking between azobenzene units. The largest macrocycle AzoM‐3‐ E with enhanced flexibility can adaptively assemble with various types of electron‐deficient guests accompanied by distortion of azobenzene. Typically, AzoM‐3‐ E assembles with the planar F4‐TCNQ to form a tetragonal geometry by C‐F···π and π‐π interactions, while the assembly with ellipsoidal C 70 via π‐π interactions induces AzoM‐3‐ E to form a boat‐shaped geometry. This work will shed new light on the development of functional conjugated macrocycles in organic electronics.

In this work, a real‐time precise electrical method to directly monitor the stochastic binding dynamics of a single supramolecule based on the host‐guest interaction between a cyclodextrin and an azo compound is reported. Different intermolecular binding states during the binding process are distinguished by conductance signals detected from graphene‐molecule‐graphene single‐molecule junctions. In combination with theoretical calculations, the reciprocating and unidirectional motions in the trans form as well as the restrained reciprocating motion in the cis form due to the steric hindrance is observed, which could be reversibly switched by visible and UV irradiation. The integration of individual supramolecules into nanocircuits not only offers a facile and effective strategy to probe the dynamic process of supramolecular systems, but also paves the way to construct functional molecular devices toward real applications such as switches, sensors, and logic devices. In‐situ real‐time electrical recordings of a photoswitchable shuttling process are realized through graphene‐molecule‐graphene single‐molecule junctions for the first time. Different motion phenomena hidden in the stochastic motion are observed directly and can be switched through irradiation of visible and UV light.

Amantadine (AMA) and its derivatives are illicit veterinary drugs that are hard to detect at very low concentrations. Developing a fast, simple and highly sensitive method for the detection of AMA is highly in demand. Here, we designed an anthracyclic compound (ABAM) that binds to a cucurbit[7]uril (CB[7]) host with a high association constant of up to 8.7 × 108 M−1. The host-guest complex was then used as a fluorescent probe for the detection of AMA. Competition by AMA for occupying the cavity of CB[7] allows ABAM to release from the CB[7]-ABAM complex, causing significant fluorescence quenching of ABAM (indicator displacement assay, IDA). The linear range of the method is from 0.000188 to 0.375 μg/mL, and the detection limit can be as low as 6.5 × 10−5 μg/mL (0.35 nM). Most importantly, due to the high binding affinity between CB[7] and ABAM, this fluorescence host-guest system shows great anti-interference capacity. Thus, we are able to accurately determine the concentration of AMA in various samples, including pharmaceutical formulations.

The host–guest interactions between baicalein (BALE) and cucurbit[8]uril (Q[8]) and the corresponding properties of the inclusion complex were studied using 1 H NMR, IR and UV–vis spectroscopy and DTA. The results showed that BALE forms an inclusion compound (1:1) with Q[8], and the properties of baicalein are changed by cucurbit[8]uril.

The construction of supramolecular recognition systems based on specific host–guest interactions has been studied in order to design selective chemical sensors. In this study, guest-responsive receptors for ATP have been designed with cyclodextrins (CyDs) as a basic prototype of the turn-on type fluorescent indicator. We synthesized dipicolylamine (DPA)-modified CyD–Cu2+ complexes (Cu·1α, Cu·1β, and Cu·1γ), and evaluated their recognition capabilities toward phosphoric acid derivatives in water. The UV-Vis absorption and fluorescence spectra revealed that Cu·1β selectively recognized ATP over other organic and inorganic phosphates, and that β-CyD had the most suitable cavity size for complexation with ATP. The 1D and 2D NMR analyses suggested that the ATP recognition was based on the host–guest interaction between the adenine moiety of ATP and the CyD cavity, as well as the recognition of phosphoric moieties by the Cu2+–DPA complex site. The specific interactions between the CyD cavity and the nucleobases enabled us to distinguish ATP from other nucleoside triphosphates, such as guanosine triphosphate (GTP), uridine triphosphate (UTP), and cytidine triphosphate (CTP). This study clarified the basic mechanisms of molecular recognition by modified CyDs, and suggested the potential for further application of CyDs in the design of highly selective supramolecular recognition systems for certain molecular targets in water.

Real‐time tracking of drug release from nanomedicine in vivo is crucial for optimizing its therapeutic efficacy in clinical settings, particularly in dosage control and determining the optimal therapeutic window. However, most current real‐time tracking systems require a tedious synthesis and purification process. Herein, a supramolecular nano‐tracker (SNT) capable of real‐time tracking of drug release in vivo based on non‐covalent host‐guest interactions is presented. By integrating multiple cavities into a single nanoparticle, SNT achieves co‐loading of drugs and probes while efficiently quenching the photophysical properties of the probe through host‐guest complexation. Moreover, SNT is readily degraded under hypoxic tumor tissues, leading to the simultaneous release of drugs and probes and the fluorescence recovery of probes. With this spatial and temporal consistency in drug loading and fluorescence quenching, as well as drug release and fluorescence recovery, SNT successfully achieves real‐time tracking of drug release in vivo (Pearson r = 0.9166, R2 = 0.8247). Furthermore, the released drugs can synergize effectively with fluorescent probes upon light irradiation, achieving potent chemo‐photodynamic combination therapy in 4T1‐bearing mice with a significantly improved survival rate (33%), providing a potential platform to significantly advance the development of nanomedicine and achieve optimal therapeutic effects in the clinic. Supramolecular nano‐tracker (SNT) is developed for real‐time tracking of drug release in vivo. SNT achieves non‐covalent drugs/probes loading and quenches probe fluorescence under physiological conditions, while releasing cargoes and restoring the probe fluorescence in tumor. Moreover, SNT facilitates chemo‐photodynamic‐based combination therapy upon light irradiation, demonstrating its potential for real‐time tracking of drug release and combination therapy.

Responsive hydrogels are one of the most frequently proposed vehicles for targeted and controlled drug delivery. Interaction between the transported drug and the three-dimensional polymer network could compromise the kinetics and the efficiency of delivery in thermoresponsive polymers. Poly( N -isopropylacrylamide) (PNIPA) gel was equilibrated with excess 500 mM aqueous solutions of three model drug molecules, phenol, ibuprofen and dopamine. These molecules affect the swelling properties of PNIPA in different ways. After determining the drug uptake and drying to constant mass, the loaded samples were studied with simultaneous thermal analysis. The difference in thermal response is interpreted in terms of the different typical molecular interactions in these systems under confined conditions. For phenol and dopamine, the water–phenol and dopamine–dopamine interactions, respectively, are stronger than that between the guest and polymer. For ibuprofen–PNIPA, the synergy in the thermal decomposition may stem from a strong polymer–ibuprofen relation.