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Enantio-discrimination and spin-dependent electrochemistry (SDE), as a manifestation of the chirality-induced spin selectivity (CISS) effect, are important phenomena that can be probed by "chiral" electrochemistry. Here, we prepared chiralized surfaces of gold and nickel, to serve as working electrodes, through effective chemisorption of enantiopure dimethyl-bis(ethylenedithio)-tetrathiafulvalene (DM-BEDT-TTF) 1, tetramethyl-bis(ethylenedithio)-tetrathiafulvalene (TM-BEDT-TTF) 2, and their capped silver nanoparticle (AgNPs) aggregate by simple incubation of the metallic substrates. The effective chemisorption was checked by means of ultrahigh vacuum x-ray photoelectron spectroscopy (XPS) and by electro-desorption experiments, i.e., cyclic voltammetry (CV) scans showing a first electro-desorption peak at about −1.0 V. The Au|1 and Au|2 chiral electrodes were successfully used in CV experiments exploiting chiral redox probes. Finally, the hybrid interfaces Ni|enantiopure 1 or 2|AgNPs served as working electrodes in SDE experiments. In particular, the hybrid chiral interfaces Ni|(R)-2|AgNPs and Ni|(S)-2|AgNPs exhibited a significant spin-filtering ability, as a manifestation of the CISS effect, with average spin polarization values of 15%. [ABSTRACT FROM AUTHOR]

Chiral recognition and enantioseparation are of paramount importance in various fields, including pharmaceuticals, agrochemicals, and material science. Covalent organic frameworks (COFs) have emerged as promising materials for chiral separation due to their unique structural features and tunable properties. This review provided a comprehensive overview of recent progress in the application of COFs and related innovative materials for chiral separation and recognition. Various strategies were analyzed for the design and synthesis of chiral COFs, including the incorporation of chiral building blocks, post‐synthetic modification, and the integration of chiral selectors. The applications of chiral COFs in chromatographic techniques, membrane separations, and other emerging methods were critically evaluated with the emphasis on their advantages and limitations. Additionally, the review summarized the potential of combining COFs with other nanomaterials, such as metal–organic frameworks (MOFs) and nanoparticles, to enhance chiral recognition and separation performance. The fundamental principles and mechanisms of chiral recognition were discussed, highlighting the role of chiral selectors and their interactions with enantiomers. Finally, current challenges and future perspectives in this field were discussed, providing insights into the development of more efficient and versatile chiral separation systems based on COFs and related materials. [ABSTRACT FROM AUTHOR]

Chiral macrocyclic arenes possess confined three-dimensional asymmetric cavities, electron-rich structures, chiral luminescence properties and excellent enantioselective recognition properties and have become a frontier and hotspot of macrocyclic chemistry and supramolecular chemistry. In recent years, there has been growing interest in the development of novel chiral macrocyclic arenes, which have found applications in various research areas. In this review, the construction, properties and functional applications of novel chiral macrocyclic arenes in enantioselective recognition, chiral sorting and construction of chiral luminescent materials according to their chiral types, including central, axial, planar, and inherent chiralities, are summarized. It is expected that this review will be helpful for research on supramolecular chemistry and for promoting the development of synthetic chemistry, materials chemistry and biochemistry. [ABSTRACT FROM AUTHOR]

Chiral recognition is crucial for applications in chiral purity assessment and biomedical fields. However, achieving chiral recognition through visible room temperature phosphorescence remains challenging. Here, two chiral molecules, designated as host and guest are synthesized, which possess similar structural configurations. A viable strategy involving a chiral configuration‐dependent energy transfer process to enable selective phosphorescence expression is proposed, thereby enabling chiral recognition in a host‐guest doping system. The chiral and structural similarity between host and guest facilitates efficient Dexter energy transfer due to the reduced spatial distance between the molecules. This mechanism significantly enhances the intensity of red phosphorescence from the guest molecule, characterized by an emission peak at 612 nm and a prolonged lifetime of 32.7 ms. This work elucidates the mechanism of chiral‐dependent energy transfer, demonstrating its potential for selectively expressing phosphorescence in chiral recognition. [ABSTRACT FROM AUTHOR]

Inherently chiral calixarenes hold great potential for applications in chiral recognition, sensing, and asymmetric catalysis due to their unique structures. However, due to their special structures and relatively large sizes, the catalytic asymmetric synthesis of inherently chiral calixarenes is challenging with very limited examples available. Here, we present an efficient method for the enantioselective synthesis of inherently chiral sulfur-containing calix[4]arenes through the desymmetrizing electrophilic sulfenylation of calix[4]arenes. This catalytic asymmetric reaction is enabled by a chiral 1,1'-binaphthyl-2,2'-diamine-derived sulfide catalyst and hexafluoroisopropanol. Various inherently chiral sulfur-containing calix[4]arenes are obtained in moderate to excellent yields with high enantioselectivities. Control experiments indicate that the thermodynamically favored C-SAr product is formed from the kinetically favored N-SAr product and the combination of the chiral sulfide catalyst and hexafluoroisopropanol is crucially important for both enantioselectivity and reactivity. Due to the special structures and relatively large sizes, the catalytic asymmetric synthesis of inherently chiral calixarenes is challenging with limited examples available. Here, the authors report the enantioselective synthesis of inherently chiral sulfur-containing calix[4]arenes through the desymmetrizing electrophilic sulfenylation of calix[4]arenes. [ABSTRACT FROM AUTHOR]

31P NMR spectroscopy is a consolidated tool for the characterization of organophosphorus compounds and, more recently, for reaction monitoring. The evolution of organic synthesis, mainly due to the combination of elaborated building blocks with enabling technologies, generated great challenges to understand and to optimize the synthetic methodologies. In this sense, 31P NMR experiments also became a routine technique for reaction monitoring, accessing products and side products yields, chiral recognition, kinetic data, intermediates, as well as basic organic parameters, such as acid‐base and hydrogen‐bonding. This review deals with these aspects demonstrating the essential role of the 31P NMR spectroscopy. The recent publications (the last ten years) will be explored, discussing the experiments of 31P NMR and the strategies accomplished to detect and/or quantify distinct organophosphorus molecules, approaching reaction mechanism, stability, stereochemistry, and the utility as a probe. [ABSTRACT FROM AUTHOR]

A capillary electrochromatography (CEC) synergistic enantioseparation system based on a novel nanomaterial synthesized by chiral molecularly imprinted polymers (CMIPs) and chiral metal organic frameworks (CMOFs) was developed. Compared with CMIPs and CMOFs alone, the enantioseparation performance of ofloxacin (OFL) of the CEC with the novel nanomaterial as stationary phases was greatly improved. CMOFs with chiral recognition ability have synergize with CMIPs to greatly improve the chiral selectivity of the novel stationary phases in CEC. As a proof-of-concept demonstration, a coated capillary column was prepared by a sol–gel method using S-OFL (template), iron-based cyclodextrin MOF (Fe-CD-MOF, a CMOF), 3-aminopropyltriethoxysilane (functional monomer), and tetraethyl orthosilicate (cross-linking agent). Then, the newly constructed CEC system has excellent enantioseparation performance of OFL with a resolution of 3.92. Finally, computerized molecular docking revealed that the difference in the binding ability of Fe-CD-MOF to ofloxacin enantiomers was an important mechanism for CEC chiral separation. This innovative development of synergistic chiral stationary phases based on CMOFs and CMIPs creates a highly efficient potential direction for enantiomer separation. [ABSTRACT FROM AUTHOR]

Chiral tetraphenylethylene (TPE) dicycle tetraaldehyde and TPE dicycle tetraacids bearing optically pure groups on the cycles were designed and synthesized. Due to the propeller-like conformation immobilization of TPE unit, this new class of TPE dicycle was resolved into M- and P-enantiomers, which could emit strong circular polarized luminescence (CPL). Interestingly, these TPE helicates displayed exceptional ability of molecule recognition. While the TPE dicycle tetraaldehyde could detect the microscale water in anhydrous tetrahydrofuran, the chiral TPE dicycle tetraacid could display different fluorescent color after interacting with two enantiomers of a wide variety of chiral amines including monoamines, diamines, and aminols, which could be applied to chiral recognition of these chiral amines. Furthermore, the emission wavelength of TPE dicycle tetraacid was found to change linearly with the enantiomer purity of chiral amine from enantiomer excess (ee) percent −100% to +100%, for the first time showing the potential for quantitative chiral analysis of chiral amines based on emission wavelength change. The emission wavelength was affected less by environmental factors than fluorescence intensity, which would enable the chiral analysis based on wavelength change with higher accuracy and repeatability. [ABSTRACT FROM AUTHOR]

Polysaccharide materials have wide applications in the field of chiral recognition. Herein, a new series of chiral materials based on chiral polysaccharide were synthesized for electrochemical enantioselective recognition of tryptophan (Trp) enantiomers. Chiral recognition was investigated via differential pulse voltammetry (DPV). Among poly (L‐lactide) La/hydroxyapatite chitosan (PLLHC‐X) series materials (PLLHC‐0, PLLHC‐1, PLLHC‐3, PLLHC‐7 PLLHC‐9 and PLLHC‐5), PLLHC‐5 has the best recognition efficiency. And the results reveal that the PLLHC‐5 displays a stronger interaction with L‐Trp than to that of D‐Trp. The synergetic effect of chiral recognition from chitosan and signal amplification from poly (L‐lactide) (PLLA) offered an easy‐handling and effective electrochemical approach for isomers discrimination to realize the chiral recognition of Trp enantiomers. The synergetic effect results in highly efficiency and thus opens up new directions in the field of chiral materials. [ABSTRACT FROM AUTHOR]

The active template synthesis of mechanically interlocked molecular architectures exploits the dual ability of various structural elements (metals or, in the case of metal-free active template synthesis, particular arrangements of functional groups) to serve as both a template for the organisation of building blocks and as a catalyst to facilitate the formation of covalent bonds between them. This enables the entwined or threaded intermediate structure to be covalently captured under kinetic control. Unlike classical passive template synthesis, the intercomponent interactions transiently used to promote the assembly typically do not 'live on' in the interlocked product, meaning that active template synthesis can be traceless and used for constructing mechanically interlocked molecules that do not feature strong binding interactions between the components. Since its introduction in 2006, active template synthesis has been used to prepare a variety of rotaxanes, catenanes and knots. Amongst the metal–ion-mediated versions of the strategy, the copper(I)-catalysed alkyne–azide cycloaddition (CuAAC) remains the most extensively used transformation, although a broad range of other catalytic reactions and transition metals also provide effective manifolds. In metal-free active template synthesis, the recent discovery of the acceleration of the reaction of primary amines with electrophiles through the cavity of crown ethers has proved effective for forming an array of rotaxanes without recognition elements, including compact rotaxane superbases, dissipatively assembled rotaxanes and molecular pumps. This Review details the active template concept, outlines its advantages and limitations for the synthesis of interlocked molecules, and charts the diverse set of reactions that have been used with this strategy to date. The application of active template synthesis in various domains is discussed, including molecular machinery, mechanical chirality, catalysis, molecular recognition and various aspects of materials science. [ABSTRACT FROM AUTHOR]

The design and synthesis of chiral covalent organic frameworks (COFs) with controlled defect sites are highly desirable but still remain largely unexplored. Herein, we report the synthesis of a defective chiral HD‐TAPB‐DMTP COF by modifying the chiral monomer helicid (HD) into the framework of an achiral imine‐linked TAPB‐DMTP COF using a chiral monomer exchange strategy. Upon the introduction of the chiral HD unit, the obtained defective chiral HD‐TAPB‐DMTP COF not only displays excellent crystallinity, large specific surface area (up to 2338 m2/g) and rich accessible chiral functional sites but also exhibits fluorescence emission, rendering it a good candidate for discrimination of amino acids. Notably, the resultant defective chiral HD‐TAPB‐DMTP COF can be used as a fluorescent sensor for enantioselective recognition of both tyrosine and phenylalanine enantiomers in water, showing enhanced fluorescent responses for the L conformations over those of the D conformations with the enantioselectivity factors being 1.84 and 2.02, respectively. Moreover, molecular docking simulations uncover that stronger binding affinities between chiral HD‐TAPB‐DMTP COF and L‐tyrosine/L‐phenylalanine in comparison to those with D‐tyrosine/D‐phenylalanine play important roles in enantioselective determination. This work provides new insights into the design and construction of highly porous defective chiral COFs for enantioselective fluorescence recognition of amino acids. [ABSTRACT FROM AUTHOR]

Enantiomer-specific oriented attachment (abbreviation ESOA), a non-classical crystallization phenomenon, has been used for chiral crystal separation since Viedma for symmetry breaking of chiral substances. The so-called enantiomer-specific oriented attachment is mainly manifested by spontaneous chiral recognition of neighboring crystals during self-assembly through specific crystal faces, which leads to chiral amplification, and thus the possible formation of purely chiral crystal aggregates. However, as of now, this method enables chiral separation of achiral molecules, while it is rarely applied in the chiral separation of conglomerates. In view of this, we verified the stability and practicality of the ESOA method in chiral crystal separation by N-benzoylglycine and N-succinopyridine from the perspective of achiral molecules and conglomerates, respectively. Besides, we tried to explore whether ESOA can be used for the resolution of racemic compounds. To this aim, we boiled ethanol aqueous (VEtOH : VWater = 3 : 2) saturated solutions of DL -isoleucine, DL -leucine or DL -valine, but did not succeed in obtaining a single chiral crystal agglomerate. This is not the result we expected, but it reinforces the fact that most of the conditions for the success of the ESOA method are that the chiral substrate is a conglomerate. And it appears that we have discovered a way to prepare a conglomerate of DL -isoleucine, DL -leucine, and DL -valine on a large scale by this method, with a view to playing a role in other special complex chiral drugs in the future. [ABSTRACT FROM AUTHOR]

We have studied the coordination chemistry of chiral imidazoline‐based C2‐symmetric ligands with zinc (II) and copper (II). Two types of bisimidazoline ligands were studied, one with the free amine (BIM‐H) and the other with the amine protected by a toluene sulfonyl group in position 6 (BIM‐Ts). The complexes formed were isolated, purified, and characterized, in particular by X‐ray diffraction studies and CD in the case of the enantiopure complexes. By playing with the choice of ligand system (enantiopure or racemate), we were able to show that the selective formation of homoleptic and heteroleptic metal complexes can be controlled by means of the chiral molecular instruction of bisimidazoline ligands. [ABSTRACT FROM AUTHOR]

This article presents a method for producing chiral ionic liquid-based polyurea microcapsules that can be magnetically separated. The method involves entrapping hydrophilic magnetic nanoparticles within chiral polyurea microspheres. The synthetic process for creating these magnetic polyurea particles involves oil-in-oil (o/o) nano-emulsification of an ionic liquid-modified magnetite nanoparticle (MNPs-IL) and an ionic liquid-based diamine monomer, which comprises a chiral bis(mandelato)borate anion, in a nonpolar organic solvent, toluene, and contains a suitable surfactant. This is followed by an interfacial polycondensation reaction between the isocyanate monomer, polymethylenepolyphenyl isocyanate (PAPI 27), and the chiral diamine monomer, which generates chiral polyurea microcapsules containing magnetic nanoparticles within their cores. The microcapsules generated from the process are then utilized to selectively adsorb either the R or S enantiomer of tryptophan (Trp) from a racemic mixture that is dissolved in water, in order to evaluate their chiral recognition capabilities. During the experiments, the magnetically separable chiral poly(ionic liquid) microcapsules, which incorporated either the R or S isomer of chiral bis(mandelato)borate, exhibited exceptional enantioselective adsorption performance. Thus, the chiral polymeric microcapsules embedded with the R-isomer of the bis(mandelato)borate anion demonstrated significant selectivity for adsorbing L-Trp, yielding a mixture with 70% enantiomeric excess after 96 h. In contrast, microcapsules containing the S-isomer of the bis(mandelato)borate anion preferentially adsorbed D-Trp, achieving an enantiomeric excess of 73% after 48 h. [ABSTRACT FROM AUTHOR]

The understanding of supramolecular chirality in self‐assembled molecular networks (SAMNs) on surfaces generates a lot of interest because of its relation to the production of chiral sensors, reactors, and catalysts. We herein report the adsorption of a prochiral solvent molecule in porous SAMNs formed by a chiral dehydrobenzo[12]annulene (cDBA) derivative. Through the prochirality recognition of a solvent molecule, the supramolecular chirality of the SAMN is switched: the cDBA exclusively forms a counter‐clockwise pore through co‐adsorption of the solvent molecule in prochiral 1,2,4‐trichlorobenzene, while in 1‐phenyloctane it produces the opposite chiral, clockwise pore. The prochirality recognition of the solvent molecule in the chiral SAMN pores is attributed to the adaptable conformational changes of the chiral chains of the cDBA molecule. [ABSTRACT FROM AUTHOR]

Inherently chiral calix[4]arenes are an excellent structural scaffold for enantioselective synthesis, chiral recognition, sensing, and circularly polarized luminescence. However, their catalytic enantioselective synthesis remains challenging. Herein, we report an efficient synthesis of inherently chiral calix[4]arene derivatives via cascade enantioselective cyclization and oxidation reactions. The three‐component reaction features a broad substrate scope (33 examples), high efficiency (up to 90 % yield), and excellent enantioselectivity (>95 % ee on average). The potential applications of calix[4]arene derivatives are highlighted by their synthetic transformation and a detailed investigation of their photophysical and chiroptical properties. [ABSTRACT FROM AUTHOR]

A supramolecular low molecular weight organogelator (CNAZO) containing azobenzene and cholesterol units was synthesized, and its applications have been studied. The CNAZO gelator displays excellent gelation ability in six kinds of organic solvents with satisfactory transparency and lower critical gelation concentrations. Meanwhile, the chirality can be transferred from the cholesterol unit to the azobenzene group, which can be reversibly modulated through 365 nm UV light irradiation and heating‐cooling treatment. Compared with D‐limonene, CNAZO can form a stable organogel and exhibits obvious CD signals in the mixed solvent that containing L‐limonene, which can be used for chiral recognition of limonene. Owing to the phase‐selective ability and porous network structure, CNAZO can also be chosen for the separation and recovery of petrol from water and be utilized for rhodamine B (RhB) adsorption with removal efficiency (Re) of 99 %. These interesting insights indicated that the CNAZO gelator could be selected in the design of sensors and in environmental remediation fields. [ABSTRACT FROM AUTHOR]

Stereoselective inhibition aided by "tailor‐made" polymeric additives is an efficient approach to obtain enantiopure compounds through conglomerate crystallization. The chemical and configurational match between the side groups of polymers and the molecules of undesired enantiomer is considered to be a necessary condition for successful stereoseparation. Whereas in this contribution, we present an effective resolution of chiral pharmaceuticals by using cellulose acetates as the additives, which stereoselectively reside on the specific crystal faces of one enantiomer and inhibit its crystal nucleation and growth through helical pattern and supramolecular interaction complementarity. An investigation of nimodipine serves as a case study to highlight the novelty of this strategy wherein R‐crystals exhibiting an impressive enantiomeric excess value of 97 % can be attained by employing a mere 0.01 wt % cellulose acetate. Guaifenesin and phenyl lactic acid are also well‐resolved by utilizing this methodology. Our work not only brings about a brand‐new design strategy for "tailor‐made" additives, but will also promote the further exploration of the endless potential for utilizing natural biomolecules in chiral recognition and resolution. [ABSTRACT FROM AUTHOR]

A reaction‐based optical relay sensing strategy that enables accurate determination of the concentration and enantiomeric ratio (er) of challenging chiral alcohols exhibiting stereocenters at the α‐, β‐, γ‐ or even δ‐position or hard‐to‐detect cryptochirality arising from H/D substitution is described. This unmatched application scope is achieved with a conceptually new sensing approach by which the alcohol moiety is replaced with an optimized achiral sulfonamide chromophore to minimize the distance between the covalently attached chiroptical reporter unit and the stereogenic center in the substrate. The result is a remarkably strong, red‐shifted CD induction that increases linearly with the sample er. The CD sensing part of the tandem assay is seamlessly coupled to a redox reaction with a quinone molecule to generate a characteristic UV response that is independent of the enantiopurity of the alcohol and thus allows determination of the total analyte concentration. The robustness and utility of the CD/UV relay are further verified by chromatography‐free asymmetric reaction analysis with small aliquots of crude product mixtures, paving the way toward high‐throughput chiral compound screening workflows which is a highly sought‐after goal in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Chiral self‐discrimination plays a critical role in supramolecular chemistry and materials science. However, an ideal strategy for achieving chiral self‐discrimination remains elusive due to the inevitable nonspecific binding of incorrect enantiomers, and insufficient intrinsic optical activity of chiral molecules. Herein, a novel 1,1′‐binaphthol (BINOL) derivative with an imide group fused at the peri‐position of one naphthol scaffold is developed, which combines the dual functionalities of aggregation‐induced emission characteristic of BINOLs, and high emission of 1,8‐naphthalimides. The multiple molecular recognition between two hydroxyl groups in BINOL units and two carbonyl groups in 1,8‐naphthalimide moieties endows the precise chiral self‐discrimination behaviors. As expected, the homochiral aggregates exhibit reversible phase transitions, switching from non‐emission to bright green emission upon absorption and desorption of methanol vapor. In contrast, the heterochiral conglomerates exhibit irreversible yellow emission changes due to the impact of chiral self‐discrimination. Such chiral self‐discrimination‐induced luminescence vapochromism can be further applied to high‐level anti‐counterfeiting and data encryption. This work provides a new perspective on smart chiral organic materials based on chiral self‐discrimination. [ABSTRACT FROM AUTHOR]

An asymmetric synthesis is a favorable approach for obtaining enantiomerically pure substances, but racemic resolution remains an efficient strategy. This study aims to elucidate the chiral resolution of aromatic amino acids and their elution order using glycopeptides as chiral selectors through molecular docking analysis. Chiral separation experiments were conducted using Vancomycin as a chiral additive in the mobile phase (CMPA) at various concentrations, coupled with an achiral amino column as the stationary phase. The Autodock Vina 1.1.2 software was employed to perform molecular docking simulations between each enantiomer (ligand) and Vancomycin (receptor) to evaluate binding affinities, demonstrate enantiomeric resolution feasibility, and elucidate chiral recognition mechanisms. Utilizing Vancomycin as CMPA at a concentration of 1.5 mM enabled the separation of tryptophan enantiomers with a resolution of 3.98 and tyrosine enantiomers with a resolution of 2.97. However, a poor chiral resolution was observed for phenylalanine and phenylglycine. Molecular docking analysis was employed to elucidate the lack of separation and elution order for tryptophan and tyrosine enantiomers. By calculating the binding energy, docking results were found to be in good agreement with experimental findings, providing insights into the underlying mechanisms governing chiral recognition in this system and the interaction sites. This comprehensive approach clarifies the complex relationship between chiral discrimination and molecular architecture, offering valuable information for creating and improving chiral separation protocols. [ABSTRACT FROM AUTHOR]

Developing chemiresistive devices for the wireless detection of complex analytes has gained considerable interest. In particular, the enantioselective recognition of chiral molecules is still a challenge. Here, we design a hybrid chemiresistive device for the wireless enantioselective discrimination of chiral analytes by combining the enantiorecognition capabilities of an inherently chiral oligomer, that is, oligo‐(3,3’‐dibenzothiophene) (BT2T4) and the insulating/conducting transition of polypyrrole (Ppy). The device is obtained by modifying each extremity of an interdigitated electrode (IDE) with Ppy on the interdigitated area and oligo‐BT2T4 on the connection pads. Due to the asymmetric electroactivity triggered by bipolar electrochemistry, the wireless enantioselective discrimination of both enantiomers of tryptophan and DOPA was achieved. A difference in the onset resistance values was obtained for both enantiomers due to a favorable or unfavorable diastereomeric interaction between the inherently chiral oligomer and the antipode of the chiral molecule. Interestingly, such a device showed a wide quantification range, from μM to mM levels. This work opens up new alternatives to designing advanced wireless devices in enantiorecognition. [ABSTRACT FROM AUTHOR]

Beyond the confines of chemistry, molecular chirality and related ideas like symmetry, asymmetry, handedness, symmetry breaking, and chiral recognition have a growing influence in science. In the current study, a twisted carbon nanobelt (TCNB) is used for the chiral discrimination of amino acids (AA) using density functional theory study. The values of interaction energy (Eint) range from −28.55 to −34.45 kcal mol–1. Two distinct trends of Eint are identified, with the TCNB demonstrating selectivity for R-enantiomers of proline and S-enantiomers of histidine. Similarly, for threonine, the TCNB is selective toward SR-threonine. Chiral discrimination energy is most pronounced for threonine@TCNB (SR and RS) enantiomeric complexes, i.e., 6.90 kcal mol–1. Quantum theory of atoms in molecules (QTAIM) and noncovalent interaction (NCI) analyses reveal that the S enantiomer in each case has maximum interactions compared to the R enantiomer. Electron density difference (EDD) and natural bond orbital (NBO) analyses indicate charge transfer from amino acids toward the belt, with RS-thre@TCNB having a maximum charge transfer, i.e., 2.260 (e–). Frontier molecular orbital (FMO) analysis reveals a decline in energy gap upon complexations. The highest decrease in energy gap is seen for R-pro@TCNB (3.42 eV from 3.59 eV), which displays high selectivity of the TCNB toward proline. The current study highlights the selectivity of the TCNB toward chiral molecules, showing a significant chiral discrimination ability for S and R enantiomers of amino acids. This work contributes valuable insights into the molecular interactions and chiral recognition involving twisted carbon nanobelts. [ABSTRACT FROM AUTHOR]

In recent years, transductors of chiral information based on conducting polymers have gained considerable attention. In particular, inherently chiral materials, which allow differentiation between the antipodes of a chiral analyte in terms of energetic variations, are highly desired. In this work, we successfully synthesized a novel inherently chiral oligomer based on an indole–benzothiophene core, namely, 2‐([2,2′‐bithiophen]‐5‐yl)‐3‐(2‐([2,2′‐bithiophen]‐5‐yl)benzo[b]thiophen‐3‐yl)‐N‐methylindole (BTIndT4). The electrochemical characterization evidences a stabilization of electrogenerated radical cations due to the presence of the indole group, which guides the oligomerization, producing well‐ordered polymeric matrices. Furthermore, the in situ electrochemical conductance analysis demonstrates a simultaneous intrachain and interchain transfer of charge carriers. Finally, the highly efficient enantiorecognition capabilities of the antipodes of the oligo‐BTIndT4 films toward the enantiomers of tryptophan and 3,4‐dihydroxyphenylalanine (DOPA), as model chiral analytes, were demonstrated. [ABSTRACT FROM AUTHOR]

Chirality plays a crucial role in the drug development process, influencing fundamental chemical and biochemical processes and significantly affecting our daily lives. This review provides a comprehensive examination of mass spectrometric (MS) methods for the enantiomeric analysis of chiral drugs. It thoroughly investigates MS‐hyphenated techniques, emphasizing their critical role in achieving enantioselective analysis. Furthermore, it delves into the intricate chiral recognition mechanisms inherent in MS, elucidating the fundamental principles that govern successful chiral separations. By critically assessing the obstacles and potential benefits associated with each MS‐based method, this review offers valuable insights for researchers navigating the complexities of chiral analysis. Both qualitative and quantitative approaches are explored, presenting a comparative analysis of their strengths and limitations. This review is aimed at significantly enhancing the understanding of chiral MS methods, serving as a crucial resource for researchers and practitioners engaged in enantioselective studies. [ABSTRACT FROM AUTHOR]

In order to improve and replace the enantiomer method outlined in the olodaterol hydrochloride draft monograph (From the European Pharmacopoeia forum), one new, simple, and fast enantioselective normal phase high‐performance liquid chromatography chiral method was developed on polysaccharide‐based Chiral MX (2) (4.6 × 250 mm, 5 μm) column. n‐Hexane, ethanol, and diethylamine in the ratio of 40:60:0.1 (V/V/V) were selected as mobile phase at a flow rate of 0.8 mL/min, and the detection was performed on a photodiode array detector at 225 nm with 5 μL injection volume. The column temperature was set at 40°C for better peak shape and sensitivity. The analysis time can be shortened to 15 min, whereas the resolution between enantiomer and olodaterol was found to be even more than 10.0, which was far better than that obtained with the reported method in this draft monograph. The developed chiral method was validated in accordance with ICH Q2 (R1), including specificity, LOD&LOQ, precision, linearity, accuracy, and robustness. Thereby, the proposed method was demonstrated to be suitable for the determination of enantiomer in olodaterol hydrochloride bulk drug and drug product. Besides, the thermodynamic parameters were evaluated on the basis of Van't Hoff plots that was used to explain correlative chiral recognition mechanisms with the chiral stationary phase. [ABSTRACT FROM AUTHOR]

Pidotimod is a chiral drug that possesses two chiral centers, resulting in three isomeric impurities (analytes, A). This study employs electrospray ionization ion trap mass spectrometry (ESI‐MS) through collision‐induced dissociation (CID) to investigate the chiral recognition of pidotimod and its three isomers to eliminate chromatographic separation. Three approaches were explored: (1) Protonated molecules in CID exhibited discriminative potential for diastereomers, with the ability to distinguish between S,S and R,R configurations, albeit with an Rchiral value of ~1.8. However, differentiation between R,S and S,R configurations was not achievable. (2) Alkali adductions (lithium and sodium) only discerned diastereomers. The Rchiral values of the diastereomers obtained from alkali adduct ions were significantly lower than those obtained from protonated ions. (3) Therefore, a third approach was used to address the challenge of distinguishing between R,S and S,R configurations, including the introduction of chiral references (ref) and transition metals (MII) to form metal‐bound complexes [MII(A)(ref)‐H]+. Additionally, we synthesized a novel ligand, 4‐(N‐tert‐butoxycarbonyl [Boc]‐L‐prolinamido)phenol (denoted as ligand A), by modifying N‐t‐Boc‐L‐Pro with 2‐aminophenol, which, in combination with CuII and NiII, enabled simultaneous differentiation of all four isomers. CuII complexes exhibited significant chiral selectivity between R,S and S,R configurations. Density functional theory calculations were performed to further elucidate the stereodynamic behavior and stoichiometry of these ions in the gas phase. These calculations revealed the interaction energy and coordination sites of the precursor ions in the gas phase, correlating well with MS/MS experiment results. Additionally, the logarithm of the CuII complexes' characteristic fragment ion abundance ratio demonstrated a strong linear relationship with enantiomeric excess (ee). This study presents a novel strategy for chiral drug quality control that eliminates chromatographic separation. [ABSTRACT FROM AUTHOR]

In this article, chiral covalent organic framework core‐shell composite CCOF‐TpPa‐Py@SiO2 was facilely synthesized by induction at room temperature. The CCOF‐TpPa‐Py@SiO2 core‐shell composite was used as a chiral stationary phase for the separation of the racemates by high‐performance liquid chromatography, which exhibits good separation performance for chiral compounds including ketones, alcohols, esters, epoxides, carboxylic acids, amides, and amines. The effects of analyte injection mass on the enantioseparation were studied. The reproducibility and stability of the CCOF‐TpPa‐Py@SiO2 chiral column were explored. The intra‐day (n = 5), inter‐day (n = 5), and inter‐column (n = 3) relative standard deviations for the migration times and resolution of benzoin were 0.32%–0.54%, 0.45%–0.61%, and 1.21%–1.53%, respectively. In addition, the chiral separation ability of the CCOF‐TpPa‐Py@SiO2 chiral column (column A) was compared with that of the MDI‐β‐CD‐Modified COF@SiO2 (column B) as well as a commercial chiral column (Chiralpak AD‐H). The chiral recognition ability of column A is complementary to that of column B and AD‐H column. The resolution mechanism of CCOF‐TpPa‐Py@SiO2 stationary phase towards chiral analyte was explored. Hence, the synthesis of CCOF‐TpPa‐Py@SiO2 core‐shell composite by induction at room temperature as chiral stationary phases for chromatographic separation has important research potential and application prospects. [ABSTRACT FROM AUTHOR]

Enantiomeric molecules generally play distinct functions in chemistry, biology, and pharmacology. Similar physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the enantiomers. We report herein an efficient approach of increasing the chiral sensing ability of β-cyclodextrin (β-CD), a widely used host molecule, in the host-guest chemistry by magnetic anisotropy. A rigid and chiral lanthanide binding tag was attached to the β-CD to amplify the changes of nuclear magnetic resonance (NMR) signals in the host-guest recognition process. The installation of the paramagnetic lanthanide ion in β-CD greatly enhances the enantiomeric discrimination up to 30-fold in comparison with the diamagnetic β-CD reference. In addition, the magnitude of the paramagnetic effects is tunable according to the diverse range of paramagnetic strength of the lanthanide series. The reported method significantly increases the chiral sensing ability of β-CD, which can be applied to other host molecules. The transferred paramagnetic effects, pseudocontact shifts (PCSs) and paramagnetic relaxation enhancements (PREs), from the host to the guest molecules, are valuable structural restraints to determine the absolute stereochemistry of the chiral analytes. The strategy does not need modification of the analytes and is complementary to the reported analytical methods that rely on the functionalization of the chiral analytes. [ABSTRACT FROM AUTHOR]

The novel ternary 2D material Bi2O2Se exhibits numerous unique properties in the optical discipline due to its distinctive structure, rendering it of significant research importance and application potential in the domains of new‐generation microelectronics, optoelectronic sensors, and multidimensional optical recognition. However, the optical anisotropy and multidimensional angular resolution of Bi2O2Se have yet to be investigated under the condition of 3D spatial variation of incidence angle. Herein, the spatial optical sensing of the few‐layer Bi2O2Se is investigated under 3D spatially varying incidence conditions using a combination of polarized Raman spectroscopy and multidimensional angle‐resolved spectroscopy. By manipulating the incident angle conditions and adjusting the sample placement angle, a comprehensive optical characterization of materials from diverse spatial orientations is conducted. It is observed that few‐layer Bi2O2Se exhibits a systematically transformed multidimensional spatial photoresponse within visible and near‐infrared wavelengths. This demonstrates the capability of Bi2O2Se as photosensitive semiconductors for 3D stereo optical detection. Furthermore, finite difference time domain simulations reveal that the spatial optical anisotropy of few‐layer Bi2O2Se can be manifested under 3D variable‐angle incidence conditions. The work serves as a crucial guide for the future of Bi2O2Se in anisotropic integrated optics applications, based on polarization‐based chiral recognition. [ABSTRACT FROM AUTHOR]

Circularly polarized phosphorescence (CPP) is increasingly recognized in materials science for its unique applications in optoelectronic devices, chiral recognition, and bioimaging. This study underscores a novel directed chiral self‐assembly strategy of purely organic phosphors into supramolecular nanostructures to achieve bright room‐temperature circularly polarized phosphorescence (RT‐CPP). RT‐CPP molecules are built on an aromatic carbonyl structure having also Br to mix (n,π*) and (π,π*) characters and to enable the heavy atom effect. Side chains are rationally designed to have strong hydrogen bonding, van der Waals interactions, and a chiral center for directed chiral self‐assembly into supramolecular nanostructures. The tightly packed resulting supramolecular nanostructures also impower efficient suppression of molecular motions, thereby minimizing non‐radiative decay and facilitating bright CPP emission at room temperature. The developed self‐assembled supramolecular structures exhibit RT‐CPP with the dissymmetry factor (glum) of ≈10−3, a high phosphorescence quantum yield of 4.1%, and a rapid triplet decay time of 180 microseconds. The presented molecular design principle enabling RT‐CPP from purely organic phosphors may pave the way for novel photonic materials. [ABSTRACT FROM AUTHOR]

Chiral recognition of enantiomers with identical mirror-symmetric molecular structures is important for the analysis of biomolecules, and it conventionally relies on stereoselective interactions in chiral chemical environments. Here, we develop a magneto-electrochemical method for the enhanced detection of chiral amino acids (AAs), that combines the advantages of the high sensitivity of electrochemiluminescent (ECL) biosensors and chirality-induced effects under a magnetic field. The ECL difference between L - and D -enantiomers can be amplified over 35-fold under a field of 3.5 kG, and the chiral discrimination can be achieved in dilute AA solutions down to the nM level. The field-dependent ECL and chronocoulometry measurements suggest that chiral AAs can lock the spins on their radicals and thus enlarge the ECL change under applied magnetic fields (magneto-ECL, MECL), which explains the field-enhanced chiral discrimination of AA enantiomers. Finally, a detailed protocol is demonstrated for the identification of unknown AA solutions, in which the species, chirality and concentration of AAs can be determined simultaneously from the 2D plots of the ECL and MECL results. This work benefits the development of field-assisted detection methods and represents a promising and universal strategy for the comprehensive analysis of chiral biomolecules. [ABSTRACT FROM AUTHOR]

Chiral molecules have similar physicochemical properties, which are different in terms of physiological activities and toxicities, rendering their differentiation and recognition highly significant. Nanozymes, which are nanomaterials with inherent enzyme-like activities, have garnered significant interest owing to their high cost-effectiveness, enhanced stability, and straightforward synthesis. However, constructing nanozymes with high activity and enantioselectivity remains a significant challenge. This review briefly introduces the synthesis methods of chiral nanozymes and systematically summarizes the latest research progress in enantioselective recognition of chiral molecules based on electrochemical methods and ultraviolet–visible absorption spectroscopy. Moreover, the challenges and development trends in developing enantioselective nanozymes are discussed. It is expected that this review will provide new ideas for the design of multifunctional chiral nanozymes and broaden the application field of nanozymes. [ABSTRACT FROM AUTHOR]

We designed and synthesized a ureido‐linked zinc bisporphyrinate [Zn2(UBis)]. CD spectra show that this zinc bisporphyrinate has the ability to sense the chirality of chiral carboxylic acids without derivatization. Our studies suggest that the phenyl ring in the linker forms π‐π interactions with porphyrin planes and that the carboxylic acid is coordinated to the zinc in the host‐guest complex. DFT calculations show that the bisporphyrin adopts a "Z"‐shaped configuration, and that the ureido group forms hydrogen bonds with carboxylic acids. The combination of π‐π interactions, coordination interactions and hydrogen bonding interactions leads to the chirality sensing ability of [Zn2(UBis)]. [ABSTRACT FROM AUTHOR]

Lysine plays a crucial role in promoting development, enhancing immune function, and improving the function of central nervous system tissues. The two configurational isomers of amino acids have significantly different effects. Currently, methods for chiral recognition of lysine have been reported; however, previous detection methods have drawbacks such as expensive equipment and complicated detection processes. Fluorescence analysis, on the other hand, boasts high sensitivity, strong selectivity, and simple operation. In this study, we synthesized four novel Binaphthyl-Amine (BINAM)-based fluorescent probes capable of specifically identifying the L-configuration of lysine among the twenty amino acids that constitute human proteins. The enantiomeric fluorescence enhancement ratio (ef or ΔIL/ΔID) reached up to 15.29, demonstrating high enantioselectivity. In addition, we assessed the probe's recognition capabilities under varying pH levels, reaction times, and metal ion conditions, along with its limit of detection (LOD) and quantum yield. Our results suggest that this probe serves as a highly stable tool for the detection of chiral lysine. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal Chemical Society Reviews. It highlights various articles and reviews that have been published in the journal. Topics covered include tunable solid-state emission, anion self-assembly, nanotag design, delayed luminescence, asymmetric synthesis, and more. The journal aims to connect the world with the chemical sciences and is published by The Royal Society of Chemistry. [Extracted from the article]

Self-assembly of M(ClO4)2 (M2+ = Ni2+, Cu2+, and Zn2+) with (1S,1′S,1′′S,2R,2′R,2′′R)-(benzenetricarbonyltris(azanediyl))tris(2,3-dihydro-1H-indene-2,1-diyl) trinicotinate (s,r-L) and the corresponding enantiomer (r,s-L) as a pair of chiral tridentate donors gives rise to the chiral cage pairs [M3(s,r- and r,s-L)2](ClO4)6. For the two pairs of [(Me2CO)(H2O)@M3(r,-s and s,r-L)2](ClO4)6 (M2+ = Ni2+ and Zn2+), the inner cavity is occupied by both an acetone and a single water molecule, whereas for the copper(II) pair of [Me2CO@Cu3(r,s- and s,r-L)2](ClO4)6 under the same conditions, the cavity is filled by only one acetone molecule. Thus, the encapsulation of guest molecules into the cages during self-assembly shows significant metal(II) ion effects. These chiral cages are effective for the enantio-recognition of chiral (S)-2-butanol and (R)-2-butanol via the shifts of the electrochemical oxidation potentials obtained by the linear sweep voltammetry (LSV) technique, density functional theory (DFT) calculations, and the chiral 2-butanol adsorption in the single-crystal-to-single-crystal (SCSC) mode. [ABSTRACT FROM AUTHOR]

The dynamic interplay of coordination bonds within metal‐organic cages offers a unique avenue for structural evolution in response to external stimuli, presenting a promising strategy for the construction of chiral assemblies. This adaptability is crucial for the selective synthesis of homochiral assemblies and advancement of asymmetric catalysis. In this study, we report the self‐assembly of an achiral square‐planar Pd(II) acceptor with a C2‐symmetric tetrapyridyl donor resulted in the formation of a racemic mixture of the chiral octahedral cage Pd4L2. The existence of this racemic mixture was confirmed using circular dichroism spectroscopy as well as single crystal X‐ray diffraction analysis. We encoded chiral information into the asymmetric cavity of the cage by encapsulating chiral aromatic guests through efficient π‐π stacking and hydrophobic interactions in aqueous media. The inclusion of a chiral guest induces a preference for one enantiomeric conformation of the cage over the other, effectively shifting the equilibrium towards a single, enantiopure host‐guest complex. While the concept of chiral guest recognition by a chiral host is well‐established, this work constitutes a remarkable example of guest‐mediated chirality transfer leading to the formation of a single enantiopure coordination complex from achiral building blocks. [ABSTRACT FROM AUTHOR]

AbstractChirality represents a fundamental attribute within living systems and is a pervasive phenomenon in the natural world. The identification and analysis of chiral materials within natural environments and biological systems hold paramount importance in clinical, chemical, and biological sciences. Within chiral analysis, there is a burgeoning focus on developing chiral sensors exhibiting exceptional selectivity, sensitivity, and stability, marking it as a forefront area of research. In the past decade (2013–2023), approximately 1990 papers concerning the application of various chiral materials in chiral sensors have been published. Biological materials and nanomaterials have important applications in the development of chiral sensors, which accounting for 26.67% and 45.24% of the material-related applications in these sensors, respectively; moreover, the development of chiral nanomaterials is closely related to the development of portable and stable chiral sensors. Natural chiral materials, utilized as selective recognition units, are combined with carriers characterized by good physical and chemical properties through functionalization to form various functional chiral materials, which improve the recognition efficiency of chiral sensors. In this article, from the perspective of biological materials, polymer materials, nanomaterials, and other functional chiral materials, the applications of chiral sensors are summarized and the research prospects of chiral sensors are discussed. [ABSTRACT FROM AUTHOR]

Chirality is a fundamental property of nature. Separation and analysis of racemates are of great importance in the fields of medicine and the production of chiral biopharmaceutical intermediates. Chiral chromatography has the characteristics of a wide separation range, fast separation speed, and high efficiency. The development and preparation of novel chiral stationary phases with good chiral recognition and separation capacity is the core and key of chiral chromatographic separation and analysis. In this work, the representative research progress of novel chiral porous crystal materials including chiral covalent organic frameworks, chiral porous organic cages, chiral metal‐organic frameworks, and chiral metal‐organic cages used as chiral stationary phases of capillary gas chromatography and high‐performance liquid chromatography over the last 4 years is reviewed in detail. The chiral recognition and separation properties of the representative studies in this review are also introduced and discussed. [ABSTRACT FROM AUTHOR]

Abstract Chiral recognition is crucial for applications in chiral purity assessment and biomedical fields. However, achieving chiral recognition through visible room temperature phosphorescence remains challenging. Here, two chiral molecules, designated as host and guest are synthesized, which possess similar structural configurations. A viable strategy involving a chiral configuration‐dependent energy transfer process to enable selective phosphorescence expression is proposed, thereby enabling chiral recognition in a host‐guest doping system. The chiral and structural similarity between host and guest facilitates efficient Dexter energy transfer due to the reduced spatial distance between the molecules. This mechanism significantly enhances the intensity of red phosphorescence from the guest molecule, characterized by an emission peak at 612 nm and a prolonged lifetime of 32.7 ms. This work elucidates the mechanism of chiral‐dependent energy transfer, demonstrating its potential for selectively expressing phosphorescence in chiral recognition.

Piano stool complexes have been studied over many years and found widespread applications in organic synthesis, catalysis, materials and drug development. We now report the first examples of quantitative chiroptical molecular recognition of chiral compounds through click‐like η6‐arene coordination with readily available half sandwich complexes. This conceptually new approach to chirality sensing is based on irreversible acetonitrile displacement of [Cp*Ru(CH3CN)3]PF6 by an aromatic target molecule, a process that is fast and complete within a few minutes at room temperature. The metal coordination coincides with characteristic circular dichroism inductions that can be easily correlated to the absolute configuration and enantiomeric ratio of the bound molecule. A relay assay that decouples the determination of the enantiomeric composition and of the total sample amount by a practical CD/UV measurement protocol was developed and successfully tested. The introduction of piano stool complexes to the chiroptical sensing realm is mechanistically unique and extends the scope of currently known methods with small‐molecule probes that require the presence of amino, alcohol, carboxylate or other privileged functional groups for binding of the target compound. A broad application range including pharmaceutically relevant multifunctional molecules and the use in chromatography‐free asymmetric reaction analysis are also demonstrated. [ABSTRACT FROM AUTHOR]

Chiral Metal‐Organic Frameworks (CMOFs) is a kind of material with great application value in recent years. Formed by the coordination of metal ions or metal clusters with organic ligands. It has ordered and adjustable pores, multi‐dimensional network structure, large specific surface area and excellent adsorption properties. This material structure combines the properties of metal‐organic frameworks (MOFs) with the chiral properties of chiral molecules. It has great advantages in catalysis, adsorption, separation and other fields. Therefore, it has a wide range of applications in chemistry, biology, medicine and materials science. In this paper, various synthesis strategies and preparation methods of chiral metal‐organic frameworks are reviewed from different perspectives, and the advantages of each method are analyzed. In addition, the applications of chiral metal‐organic framework materials in enantiomer recognition and separation, circular polarization luminescence and asymmetric catalysis are systematically summarized, and the corresponding mechanisms are discussed. Finally, the challenges and prospects of the development of chiral metal‐organic frame materials are analyzed in detail. [ABSTRACT FROM AUTHOR]

Chirality represents a fundamental characteristic inherent in nature, playing a pivotal role in the emergence of homochirality and the origin of life. While the principles of chirality in organic chemistry are well‐documented, the exploration of chirality within inorganic crystal structures continues to evolve. This ongoing development is primarily due to the diverse nature of crystal/amorphous structures in inorganic materials, along with the intricate symmetrical and asymmetrical relationships in the geometry of their constituent atoms. In this review, we commence with a summary of the foundational concept of chirality in molecules and solid states matters. This is followed by an introduction of structural chirality and electronic chirality in three‐dimensional and two‐dimensional inorganic materials. The construction of chirality in inorganic materials is classified into physical photolithography, wet‐chemistry method, self‐assembly, and chiral imprinting. Highlighting the significance of this field, we also summarize the research progress of chiral inorganic materials for applications in optical activity, enantiomeric recognition and chiral sensing, selective adsorption and enantioselective separation, asymmetric synthesis and catalysis, and chirality‐induced spin polarization. This review aims to provide a reference for ongoing research in chiral inorganic materials and potentially stimulate innovative strategies and novel applications in the realm of chirality. [ABSTRACT FROM AUTHOR]

The document is the contents list for the journal "Chemical Communications" published on June 7, 2024. It includes articles on various topics such as the rational design and biomedical application of BODIPY-based photocages, synthesis and applications of porous protein crystals, and the construction of stable radical hydrogen-bonded metal-organic frameworks. The journal is published by The Royal Society of Chemistry, a leading chemistry community that connects the world with the chemical sciences. [Extracted from the article]

Different approaches to achieve 2D supramolecular polymers, as an alternative to the covalent bottom‐up approaches reported for the preparation of 2D materials, are reviewed. The significance of the operation of weak non‐covalent forces to induce a lateral growth of a number of self‐assembling units is collected. The examples of both thermodynamically and kinetically controlled formation of 2D supramolecular polymers showed in this review demonstrate the utility of this strategy to achieve new 2D materials with biased morphologies (nanosheets, scrolls, porous surfaces) and showing elegant applications like chiral recognition, enantioselective uptake or asymmetric organic transformations. Furthermore, elaborated techniques like seeded or living supramolecular polymerizations have been demonstrated to give rise to complex 2D nanostructures. [ABSTRACT FROM AUTHOR]

Using polystyrene two-dimensional photonic crystal as template, l-lysine molecularly imprinted two-dimensional photonic crystal hydrogel (l-Lys MIPCH) sensor with highly sensitive response to l-lysine was prepared by photoinitiated polymerization. The response performance of the l-Lys MIPCH sensor was investigated by observing the change of the diameter of the Debye ring (ΔD) and the structural color of the sensor. In the process of recognizing l-Lys molecules by l-Lys MIPCH sensor, the volume of hydrogel swells, the diameter of Debye ring decreases, and the particle spacing of photonic crystal increases. As the l-Lys concentration increased from 0 to 10−4 mol/L, the diameter of Debye ring decreased by 15.7 mm, the particle spacing of photonic crystals increased by 75.1 mm, and the structural color of hydrogel changed from blue to red correspondingly. When the l-Lys concentration was in the range of 10−12–10−4 mol/L, there was a linear relationship between the change in the diameter of the Debye ring (ΔD) and the logarithm value of the l-Lys concentration (lgc), and the linear relationship was as follows: ΔD = 19.04 + 0.90 lgc, R2=0.9962. In addition, the detection limit of the sensor is as low as 10−16 mol/L. The prepared sensor not only has high selectivity, but also can be used for chiral recognition of l-Lys, and the results of l-Lys in the actual sample of lysiinositol vitamin B12 oral solution were also satisfactory. [ABSTRACT FROM AUTHOR]

The chiral H8-BINOL derivatives R-1 and R-2 were efficiently synthesized via a Suzuki coupling reaction, and they can be used as novel dialdehyde fluorescent probes for the enantioselective recognition of R/S-2-amino-1-phenylethanol. In addition, R-1 is much more effective than R-2. Scanning electron microscope images and X-ray analyses show that R-1 can form supramolecular vesicles through the self-assembly effect of the π-π force and strong hydrogen bonding. As determined via analysis, the fluorescence of the probe was significantly enhanced by mixing a small amount of S-2-amino-1-phenylethanol into R-1, with a redshift of 38 nm, whereas no significant fluorescence response was observed in R-2-amino-1-phenylethanol. The enantioselective identification of S-2-amino-1-phenylethanol by the probe R-1 was further investigated through nuclear magnetic titration and fluorescence kinetic experiments and DFT calculations. The results showed that this mechanism was not only a simple reactive probe but also realized object recognition through an ICT mechanism. As the intramolecular hydrogen bond activated the carbonyl group on the probe R-1, the carbonyl carbon atom became positively charged. As a strong nucleophile, the amino group of S-2-amino-1-phenylethanol first transferred the amino electrons to a carbonyl carbocation, resulting in a significantly enhanced fluorescence of the probe R-1 and a 38 nm redshift. Similarly, S-2-amino-1-phenylethanol alone caused severe damage to the self-assembled vesicle structure of the probe molecule itself due to its spatial structure, which made R-1 highly enantioselective towards it. [ABSTRACT FROM AUTHOR]

Four cellulose derivatives bearing benzothienyl or carbazolyl fluorophore pendants were successfully synthesized through carbamoylation followed by Steglich esterification or only esterification process, respectively. The enantioselective fluorescent sensing properties of the obtained derivatives were then evaluated using eight chiral substrates, including chiral aromatic amines and chiral amino alcohol-based drug intermediates. The four bulky host macromolecules exhibited good enantioselective fluorescence response to most of the tested guests with high enantioselectivity and sensitivity. Especially, a high enantiomeric fluorescence difference ratio (ef = 37.16) was achieved on cellulose tris(2-benzothienylformate) (Cel-3) for the α-methylbenzylamine (Q2), an important chiral agricultural drug intermediate. Worthy to be mentioned, an interesting opposite fluorescence response and a dual fluorescence enhancement pattern were also observed on the benzothienyl derivative Cel-3 for the enantiomer pairs of 1-(4-methoxyphenyl) ethylamine (Q3) and phenylglycinol (Q6), a critical intermediate for chiral drug as an antilipemic agent in high demand, respectively. It indicated that the bulky Cel-3 possessed excellent enantioselective fluorescent sensing properties to the chiral aromatic amine and amino alcohols, revealing good potential as efficient chiral fluorescent sensors. It was speculated that a beneficial chiral domain may be constructed by the appropriate arrangement of bulky conjugated benzothienyl or carbazolyl pendants on the phenylcarbamates or esters surrounding the helical backbone of cellulose, which was crucial for the efficient chiral fluorescent sensing performance. The introduction of bulky fluorophore pendants on the cellulose phenylcarbamates or esters presents an efficient strategy to produce effective chiral fluorescent recognition materials. [ABSTRACT FROM AUTHOR]

The jammed liquid‐liquid interface offers an elegant approach to achieve non‐equilibrium shapes of liquids. The interfacial jamming subsequently brings about formation of 2D "solid‐like" assembly. In this work, biphasic reaction between a perylenediimide based luminogen benzoperylenediimide monoanhydride (Bp(Im)2MA) and diamines are demonstrated that rendered amide bond formation and in turn amide nanoconjugates across the oil‐water interface. Amide nanoconjugates formed with different diamines showed diamine alkyl chain length dependent varied interfacial properties and sizes. Jamming of the interface is judiciously utilized to induce aggregation of amide nanoconjugates which successfully established macroscopic Aggregation Induced Emission‐switching (AIE‐switching) behavior. Further, the versatility of this approach is extended to analyze the reactivity of chiral amino acids. The reaction between the Bp(Im)2MA luminogen and chiral amino acids exhibits macroscopic enantioselectivity at jammed interface via diverse surface coverage of the amino acids‐based amide nanoconjugates. The formation of discrete nanoscopic amide interfacial assembly for each of the L‐ and D‐ amino acids isomers is corroborated with Atomic Force Microscopy (AFM) images. This study extends a fascinating pathway to aid in understanding and fabrication of structurally diverse jammed interfaces and aggregation of organic molecules across an oil‐water interface. [ABSTRACT FROM AUTHOR]