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We herein describe the synthesis of a new class of axially chiral aza/boracyclophanes (BDN1, BXN1, BDB1 and BXB1) using binaphthyls as chiral building blocks and the main-group (B/N) chemistry with tunable electronic effects. All macrocycles substituted with triarylamine donors or triarylborane acceptors are strongly luminescent. These macrocycles showed two distinct meta and para π-conjugation pathways, leading to the formation of quasi figure-of-eight and square-shaped conformations. Interestingly, comparison of such structural models revealed that the former type of macrocycles BXN1 and BXB1 gave higher racemization barriers relative to the other ones. The results reported here may provide a new approach to engineer the optical stability of π-conjugated chiral macrocycles by controlling π-substitution patterns. The ring constraints induced by macrocyclization were also demonstrated to contribute to the configurational persistence as compared with the open-chain analogues p-BTT and m-BTT.

Molecules with a π-system that can be mapped onto a Möbius strip may display Möbius aromaticity. Such molecules are difficult to synthesize because they have a twisted structure. Recently, we combined chiral [6]helicene and fluorescent [7]cycloparaphenylene, and synthesized the first helicene para -phenylene ([6,7]HPP) carbon nanohoop. We have demonstrated that this design strategy ultimately provides a Möbius topology of the molecular π-electron system and, therefore, offers the potential to study Möbius aromaticity experimentally. In addition, the synthesized nanohoop exists as a mixture of conformers in solution. Some of the conformers possess a different orientability of their π-systems, i.e., they differ in their topology. As a result, the recorded circularly polarized luminescence of isolated enantiomers displays both left- and right-handedness of the emitted light, each emanating from a conformer with a different π-system topology. Therefore, [6,7]HPP provided the first experimental evidence of such topological bistability in carbon nanohoops. [ABSTRACT FROM AUTHOR]

Smart materials with circularly polarized luminescence (CPL) tunable ability show great potential for advanced information storage and encryption. While an effective integration of high photoluminescence quantum yield (PLQY) and facile regulation of CPL property in thin films are of great significance, it is challenging due to the scarcity of suitable materials and complexity of systems. Herein, a novel acid‐responsive CPL tunable molecule is designed by combining an aggregation‐induced emission (AIE) component (TPE), an acid‐responsive luminophore (Rhodol), and a chiral aniline. Benefitting by the “AIE” effect of TPE and acid‐sensitive nature of Rhodol, the acidified molecule (S‐Rhodol‐TPE) exhibits a high PLQY even when doped in the polymer substrate at high concentrations. In addition, due to the fluorescence resonance energy transfer (FRET) process between TPE and Rhodol, the emission color of S‐Rhodol‐TPE can be easily regulated by the doped ratio and acidified degree of S‐Rhodol‐TPE in the polymer film. This work exhibits a unique approach to achieving smart CPL‐tunable films with high PLQYs and multiple emission color‐regulation properties, which can undoubtedly facilitate the progress of CPL tunable materials. [ABSTRACT FROM AUTHOR]

Chiral carbon dots (CDs) with circularly polarized luminescence (CPL) are one of the most dynamic areas of modern science. However, the design, preparation, and ambiguity mechanism of solid‐state CPL‐active CDs remains a formidable challenge. Herein, for the first time, CDs with customized chiroptical activities in the solid state, especially CPL, are transcribed from chiral metal–organic framework (CMOFs) via a bottle‐around‐ship strategy. Within these CMOFs⊃CDs assemblies, CDs inherited the chirality of the host CMOFs through host–guest interactions, which is revealed by density functional theory (DFT) simulations and experimental results, and amplified the luminescence dissymmetry factor (glum) by effective artificial chiral light‐harvesting systems. Impressively, CMOFs⊃CDs in pairs generated color‐tunable CPL and white CPL with chromaticity coordinates of (0.32, 0.32). Furthermore, benefiting from excellent processability, as luminescent coatings and 3D printing inks, a white circularly polarized light‐emitting diode, and an extended 3D model “light bulb” featuring white CPL are successfully fabricated, respectively. This strategy paves a new avenue for the synthesis and advanced application of solid‐state CPL‐active CDs‐based materials. [ABSTRACT FROM AUTHOR]

The fabrication of materials that can switch between circularly polarized luminescence (CPL) signals is both essential and challenging. Here, two new halogen‐bonded fluorescent molecular photoswitches, namely, HB‐switch 1 and HB‐switch 2, containing α‐cyano‐substituted diarylethene compounds with different end groups were developed. Upon exposure to specific UV or visible light wavelengths, they exhibited controllable and reversible Z/E photoisomerization. When these switches were integrated into blue‐phase liquid crystals (BPLCs), the temperature range of BP significantly expanded. Notably, the BP system incorporating HB‐switch 1 exclusively achieved reversible polarization inversion of CPL signals under irradiation with specific UV/Visible light and during cooling/heating. The photo/thermal dual‐response behavior of the CPL signals can be attributed to the phase transition from a high‐symmetry 3D BP Icubic lattice to a low‐symmetry 1D helical superstructure induced by the Z/E photoisomerization of HB‐switch 1 and temperature changes. This study underscores the significance of employing halogen‐bond assembly strategies to design materials with switchable CPL signals, opening new possibilities for CPL‐active systems. [ABSTRACT FROM AUTHOR]

We found that during the chiral co-assembly process, the structural symmetry of achiral Py-based emitters could cause different chiral co-assembly modes, leading to the tunable CPL emission behaviors of the resulting co-assemblies. Most importantly, this kind of chiral co-assembly (R / S -B) 1 -(Py-2) 7 can form highly ordered helical nanofiber through intermolecular layered packing mode, leading to the promoted chiral induction and amplification effects. [Display omitted] The regulation of circularly polarized luminescence (CPL) behavior is of great significance for practical applications. Herein, we deliberately designed three achiral pyrene derivatives (Py-1 , Py-2 , and Py-3) with different butoxy-phenyl substituents and the chiral binaphthyl-based inducer ( R/S -B) with anchored dihedral angle to construct chiral co-assemblies, and explored their induced CPL behaviors. Interestingly, the resulting co-assemblies demonstrate tunable CPL emission behaviors caused by the structural symmetry effect of achiral pyrene-based emitters during the chiral co-assembly process. And in spin-coated films, the dissymmetry factor (g em) values were 9.1 × 10-3 for (R/S- B) 1 -(Py-1) 10 , 5.6 × 10-2 for (R/S- B) 1 -(Py-2) 7 , and 8.6 × 10-4 for (R/S- B) 1 -(Py-3) 1 , respectively. The strongest CPL emission (| g em | = 5.6 × 10-2, λ em = 423 nm, QY = 34.8 %) was detected on (R/S- B) 1 -(Py-2) 7 due to the formation of regular and ordered helical nanofibers through the strong π-π stacking interaction between the R/S- B and the achiral Py-2 emitter. The strategy presented here provides a creative approach for progressively regulating CPL emission behaviors in the chiral co-assembly process. [ABSTRACT FROM AUTHOR]

Optical materials with circularly polarized luminescence (CPL) features have attracted a growing interest due to their crucial role in biological sensing, display, spintronics, information storage, and so forth. However, CPL emissions in hybrid nanoparticle systems, in particular, chirality transfer induced CPL from chiral plasmonic nanoparticles, have rarely been explored due to a lack of effective bottom-up synthesis method. Herein, we creatively take advantage of the newly introduced chiral plasmonic nanoparticles-gold nanohelicoid (GNH) to excite the CPL of achiral Rhodamine 6G (R6G). The fabricated GNH@R6G-SiO2 shows obvious CPL signals with ∣glum∣ up to 0.014. Compared with the single GNH, the photoluminescence (PL) dissymmetry factor of the single GNH@R6G-SiO2 is similar, but with 25 folds higher PL intensities under different circular polarization. Our research not only offers an effective and feasible method to fabricate single-particle level CPL-active materials, but also provides guidelines on how to regulate the CPL of achiral luminophores from chiral plasmonic nanostructures, thereby enlarging the category and quantity of CPL-active materials that can be applied for photonic technologies and visualization biosensing, especially some intracellular chirality related detection. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescence (CPL) materials have received widespread attention due to their remarkable performance and broad applications. However, current CPL material research primarily focuses on tunable color, intensity, and reversibility. Constructing CPL with adjustable lifetime remains a significant challenge. Herein, a series of CPL polymeric materials with tunable lifetime were obtained by employing phosphorescent terephthalic acid and chiral organic small molecule R/S-BNAF (a luminescent binaphthol derivative) to copolymerize with acrylamide in different ratios. It was verified that this performance results from the different energy transfer efficiency between luminophores with varying ratios of the monomers for copolymerization. This strategy to realize CPL with tunable lifetime by modulating the energy transfer efficiency will provide a new perspective to broaden the applications of CPL materials. [ABSTRACT FROM AUTHOR]

The self‐assembled cellulose nanocrystal (CNC) film has a left‐handed layered structure, which makes the reflection of right‐handed circularly polarized (CP) light a challenge. Herein, a nematic phase layer is designed and inserted into the chiral organization, to work as a half‐wave retarder and make the ambidextrous CP light reflection. The maximum reflectivity exceeds 80%, which breaks the 50% limitations of single‐direction light reflection and is the current maximum in all the reported CNC‐based films. This “sandwich‐like” structure displays different optical properties on both sides, displayed as the chromatism and the inversion of the circular dichroism signals. The dual CP light reflection and direction‐dependent optical phenomena are reserved in the synthesized circularly polarized luminescence (CPL) film, with the dissymmetry factor (glum) of −0.4245. However, this luminescent intensity and single‐direction emission are not enough in advanced optical systems. This work designs a triple CPL amplification path and develops the handedness inversion strategy, with the glum of −1.0551 and 0.4082. Then, the dual‐directional CPL emission films are designed, where the chiral optics can be switched on‐demand. Finally, the photonic crystal films are applied in the anti‐counterfeit and chiral superstructure induction. [ABSTRACT FROM AUTHOR]

Circularly polarized multi‐resonance thermally activated delayed fluorescence (CP‐MR‐TADF) materials, capable of achieving circularly polarized luminescence (CPL), play a crucial role in the field of 3D display. In this study, two pairs of axial chiral MR‐TADF enantiomers, (R/S)‐S‐AX‐BN and (R/S)‐SO2‐AX‐BN, are synthesized by fusing biphenyl skeletons containing sulfur/sulfone with classic B/N‐embedded polycyclic aromatic hydrocarbons. These compounds exhibit good photophysical properties with intense CPL. (R/S)‐S‐AX‐BN and (R/S)‐SO2‐AX‐BN display green photoluminescence, with peaks at 489 and 495 nm, full‐width at half‐maximum (FWHM) values of 21 and 20 nm in toluene, and dissymmetry factors (|gPL|) of 3.5 × 10−3 and 2.3 × 10−3 in doped films, respectively. Additionally, circularly polarized organic light‐emitting diodes (CP‐OLEDs) fabricated from (R/S)‐S‐AX‐BN and (R/S)‐SO2‐AX‐BN exhibit narrow electroluminescence (EL) spectra with FWHMs of 22 and 21 nm. These CP‐OLEDs achieve high maximum external quantum efficiencies of 33.5% and 31.5%, with relatively low efficiency roll‐offs. Furthermore, they exhibit high |gEL| factors of 3.3 × 10−3 and 2.2 × 10−3, respectively, representing the highest values among axial chiral analogs. This work introduces a novel approach for designing axial chiral CP‐MR‐TADF molecules and provides a reference for fabricating narrowband CP‐OLEDs with high efficiency and intense CPL. [ABSTRACT FROM AUTHOR]

This work utilizes the self‐assembled cellulose nanocrystals (CNCs) as the host chiral template and fabricates a circularly polarized luminescence (CPL) film. By manipulating the photonic bandgap, the synthesized film integrates a strong CPL signal and superior mechanical flexibility. Without losing the CPL activity, the ultimate strain of 19% has exceeded most CNC‐based chiral luminescent assemblies, which enables them candidates in the optical sensor and wearable device. Meanwhile, the film has a humidity‐stimulus CPL response, with the dissymmetry factor (glum) close to 0.51. This responsive process is reversible and the optical properties can recover upon drying. Next, by manipulating the optical pathway, this work achieves on‐demand CPL direction control and meets the considerable intensity of reversed optical signals (glum: ‐0.35), avoiding the structure disruption and direction random under the external stimuli, which opens a new insight into the optical regulations. Furthermore, this work combines the in situ growth strategy and first synthesizes the dynamic‐switchable dual‐direction CPL film. Optics in both directions can be inverted simultaneously by exchanging the growth sequences. Finally, multimodal optics, excellent stability, and green manufacturing make them welcome in the advanced anti‐counterfeit areas, with the features of lossless and long‐time useful. [ABSTRACT FROM AUTHOR]

Here, we successfully synthesized four structurally analogous, self‐assembled chiral molecular tubes with relatively high yields. This achievement involved the condensation of six equivalents of enantiomerically pure trans‐cyclohexane‐1,2‐diamine (trans‐CHDA) and three equivalents of the corresponding tetraformyl precursor. Each precursor was equipped with a luminescent linker terminated by two m‐phthalaldehyde units. Even though these tetraformyl precursors are barely soluble in almost all organic solvents, the molecular tubes are highly soluble in nonpolar solvents such as chloroform, allowing us to fully characterize them in solution. The stereo‐chirality of the chiral bisamino building blocks endows the frameworks of molecular tubes with planar chirality. As a consequence, all of these molecular tubes exhibit circularly polarized luminescence (CPL) with relatively large dissymmetry values |glum| up to 7×10−3, providing an efficient method for synthesizing CPL‐active materials. [ABSTRACT FROM AUTHOR]

Large dissymmetry factor of the circularly polarized luminescence (gCPL) was observed in ligand and coordination tuned chiral tetrakis europium (Eu(III)) complexes with ammonium cations. The gCPL value was estimated to be −1.54, which is the largest among chiral luminescent molecules. Through photophysical measurements, single crystal X‐ray structural analyses and quantum chemical calculations, changes in the geometric and electronic structures were observed for a series of chiral tetrakis Eu(III) complexes which enhanced the gCPL value. The emission quantum yield and photosensitized energy transfer efficiencies of chiral Eu(III) complexes with ammonium cations were also larger than those of chiral Eu(III) complex with Cs+. Based on the systematic modifications and analyses for chiral tetrakis Eu(III) complex, effect of the ammonium cation on enhanced CPL brightness is reported. [ABSTRACT FROM AUTHOR]

Stimulus‐responsive materials that exhibit efficient circularly polarized luminescence (CPL) have gained much interest for application in advanced smart photonics. Herein, the CPL‐active enantiomorphic 0D Sb3+‐doped (R/S)2InCl7 (R/S = R/S‐2‐methylpiperazine) are synthesized via a solution method. They show efficient broadband yellow emission with a near‐unity photoluminescence quantum yield and a CPL asymmetry factor of 1.7 × 10−3. Their fascinating chiroptical activity should be attributed to the chirality transfer and self‐trapped exciton emission caused by strong electron–phonon interaction. Particularly, H2O‐induced structural transformation is demonstrated to obtain non‐emission of Sb3+‐doped (R/S)2InCl7·H2O after exposure to a humid environment. Importantly, Sb3+‐doped (R/S)2InCl7 exhibits unique nonlinear optical responses, and the rotation angle between the quarter‐wave plate and linearly polarized plate can regulate the reversible switching of Sb3+‐doped (R/S)2InCl7 between yellow emission and negligible luminescence. Moreover, a circularly polarized white light‐emitting diode is fabricated by combining blue phosphors BaMgAl10O17:Eu2+, and the device exhibits tunable switching control of positive and warm white light by regulating the rotation angle of linear polarizer plate. Based on the tunable optical responses of Sb3+‐doped (R/S)2InCl7, a programmable multi‐mode fluorescence encoding system is constructed, and four‐level information encryption and three‐level encrypted 3D color codes are also realized in a further proof‐of‐concept experiment. [ABSTRACT FROM AUTHOR]

Supramolecular assembly frameworks (SAFs) represent a new category of porous materials, utilizing non‐covalent interactions, setting them apart from metal–organic frameworks (MOFs) and covalent organic frameworks (COFs). This category includes but is not restricted to hydrogen‐bonded organic frameworks and supramolecular organic frameworks. SAFs stand out for their outstanding porosity, crystallinity, and stability, alongside unique dissolution‐recrystallization dynamics that enable significant structural and functional modifications. Crucially, their non‐covalent assembly strategies allow for a balanced manipulation of porosity, symmetry, crystallinity, and dimensions, facilitating the creation of advanced crystalline porous materials unattainable through conventional covalent or coordination bond synthesis. Despite their considerable promise in overcoming several limitations inherent to MOFs and COFs, particularly in terms of solution‐processability, SAFs have received relatively little attention in recent literature. This Minireview aims to shed light on standout SAFs, exploring their design principles, synthesis strategies, and characterization methods. It emphasizes their distinctive features and the broad spectrum of potential applications across various domains, aiming to catalyze further development and practical application within the scientific community. [ABSTRACT FROM AUTHOR]

We present the inaugural synthesis of a chiral teropyrene achieved through a four‐fold alkyne benzannulation catalyzed by InCl3, resulting in good yields. The product underwent thorough characterization using FT‐Raman and FT‐IR spectroscopies, demonstrating a close agreement with calculated spectra. X‐ray crystallographic analysis unveiled a notable twist in the molecule's backbone, with an end‐to‐end twist angle of 51°, consistent with computational predictions. Experimentally determined enantiomeric inversion barriers revealed a significant energy barrier of 23 kcal/mol, facilitating the isolation of enantiomers for analysis by circular dichroism (CD) and circularly polarized luminescence (CPL) spectroscopies. These findings mark significant strides in the synthesis and characterization of chiral teropyrenes, offering insights into their structural and spectroscopic properties. [ABSTRACT FROM AUTHOR]

Circularly polarized light emitting active materials are of great interest, and the convenient tuning of the circularly polarized luminescence (CPL) remains a significant challenge. Integrating fluorescent materials into chiral photonic crystals to achieve tunable CPL is a promising approach, allowing efficient manipulation of CPL by adjusting the photonic band gap (PBG). We combined carbon quantum dots (CQDs) with hydroxypropyl cellulose (HPC), which self-assembles into a cholesteric liquid crystal (CLC). The helical structure can selectively reflect right circularly polarized (RCP) light, achieving strong circular dichroism (CD) and high CPL dissymmetry factor glum. In addition, the chiral template is thermo-responsive. The CPL wavelength can be adjusted by regulating the PBG position through temperature adjustment, while the chirality of CPL keeps high especially in the heating process. This work enables stimuli-responsive manipulation of CPL under one template through temperature regulation, which may open up enormous possibilities for the cellulose-based material in different areas. [ABSTRACT FROM AUTHOR]

Organic materials with switchable dual circularly polarized luminescence (CPL) are highly desired because they can not only directly radiate tunable circularly polarized light themselves but also induce CPL for guests by providing a chiral environment in self‐assembled structures or serving as the hosts for energy transfer systems. However, most organic molecules only exhibit single CPL and it remains challenging to develop organic molecules with dual CPL. Herein, novel through‐space conjugated chiral foldamers are constructed by attaching two biphenyl arms to the 9,10‐positions of phenanthrene, and switchable dual CPL with opposite signs at different emission wavelengths are successfully realized in the foldamers containing high‐polarizability substitutes (cyano, methylthiol and methylsulfonyl). The combined experimental and computational results demonstrate that the intramolecular through‐space conjugation has significant contributions to stabilizing the folded conformations. Upon photoexcitation in high‐polar solvents, strong interactions between the biphenyl arms substituted with cyano, methylthio or methylsulfonyl and the polar environment induce conformation transformation for the foldamers, resulting in two transformable secondary structures of opposite chirality, accounting for the dual CPL with opposite signs. These findings highlight the important influence of the secondary structures on the chiroptical property of the foldamers and pave a new avenue towards efficient and tunable dual CPL materials. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescence (CPL) is promising for applications in many fields. However, most systems involving CPL are within the visible range; near‐infrared (NIR) CPL‐active materials, especially those that exhibit high glum values and can be controlled spatially and temporally, are rare. Herein, dynamic NIR‐CPL with a glum value of 2.5×10−2 was achieved through supramolecular coassembly and energy‐transfer strategies. The chiral assemblies formed by the coassembly between adenosine triphosphate (ATP) and a pyrene derivative exhibited a red CPL signal (glum of 10−3). The further introduction of sulfo‐cyanine5 resulted in a energy‐transfer process, which not only led to the NIR CPL but also increased the glum value to 10−2. Temporal control of these chiral assemblies was realized by introducing alkaline phosphatase to fabricate a biomimetic enzyme‐catalyzed network, allowing the dynamic NIR CPL signal to be turned on. Based on these enzyme‐regulated temporally controllable dynamic CPL‐active chiral assemblies, a multilevel information encryption system was further developed. This study provides a pioneering example for the construction of dynamic NIR CPL materials with the ability to perform temporal control via the supramolecular assembly strategy, which is expected to aid in the design of supramolecular complex systems that more closely resemble natural biological systems. [ABSTRACT FROM AUTHOR]

Materials generating circularly polarized luminescence (CPL) have received increasing interest due to their potential applications in bioimaging, sensing, anticounterfeiting, and display technologies. The possibility of efficient CPL generation is explored for organic molecules, inorganic materials, and their hybrid systems. A chiral plasmonic nanostructure is one candidate for generating strong and highly dissymmetric CPL by coupling with the surrounding luminescent material. Here, the inherent luminescence of gold nanoparticles can produce CPL without using any secondary material is suggested. In this study, the generation of circularly polarized two‐photon‐induced photoluminescence (TPI‐PL) from chiral gold nanostructures is demonstrated. Measurements of TPI‐PL show that it has a strong dissymmetry factor of ≈0.7 for a single chiral Au nanoparticle. A theoretical simulation study showed that a local chiral electromagnetic field confined to the chiral gap structures contributes to the high degree of circular polarization in TPI‐PL. It is believed that this work provides a new route for novel CPL‐generating materials with strong dissymmetry and holds promise for various applications using CPL technology. [ABSTRACT FROM AUTHOR]

The chiral materials and circularly polarized organic light‐emitting diodes (CP‐OLEDs) have potential applications in 3D display due to the generation of circularly polarized luminescence (CPL). However, achieving a combination of chirality, high efficiency, and narrowband emission for thermally activated delayed fluorescence (TADF) materials has proven to be a challenging endeavor, often involving complicated synthesis and chiral separation processes. In this study, a simple design approach is introduced by direct connection of the multiple resonance (MR) skeleton and chiral (R/S)‐1,1′‐binaphthyl units, obtaining two pairs of chiral MR‐TADF enantiomers (R/S)‐DtCzB‐OBN and (R/S)‐DtCzB‐BN without chiral resolution. These enantiomers exhibit blue‐green emissions with photoluminescence quantum efficiencies of up to 98% in doped films and full‐width at half‐maximum of 22 nm both in toluene and in the device. Furthermore, (R/S)‐DtCzB‐OBN and (R/S)‐DtCzB‐BN display symmetric CPL spectra with dissymmetry factors (gPL) of + 3.86(± 0.317) × 10−4/‐3.37(± 0.317) × 10−4 and + 7.09(± 0.233) × 10−4/‐7.74(± 0.233) × 10−4, respectively. The CP‐OLEDs based on (R/S)‐DtCzB‐OBN and (R/S)‐DtCzB‐BN exhibit impressive maximum external quantum efficiencies of 30.0% and 33.9%, as well as gEL factors of +3.40(± 0.362) × 10−4/‐3.11(± 0.362) × 10−4 and + 7.99(± 0.391) × 10−4/‐8.19(± 0.391) × 10−4, respectively. This research proposes a strategy for directly constructing chiral MR‐TADF materials for high‐performance CP‐OLEDs, avoiding complicated chiral separation. [ABSTRACT FROM AUTHOR]

The modulation of circularly polarized luminescence (CPL) has become an increasingly prominent area of research. In this study, we propose a unique "one-excitation-to-three-emissions" CPL system through the co-assembly of an upconversion system, incorporating one sensitizer (Pt(II) mesotetraphenyl tetrabenzoporphyrine, PtTPBP) and two annihilators (R/S-DPA and R/S-BDP) within liquid crystals. The chiral nature of the annihilators induces a transformation of the nematic liquid crystal into chiral nematic liquid crystals (N*LC), establishing an excellent chiral matrix. Upon the incorporation of the sensitizer PtTPBP and subsequent excitation at 635 nm, the system demonstrates two independent triplet-triplet annihilation photon upconversion (TTA-UC) with the emission in blue and yellow, aided by thermally activated triplet-triplet energy transfer (TTET). This is accompanied by the simultaneous generation of upconverting circularly polarized luminescence (UC-CPL) and downshifting near-infrared circularly polarized luminescence (DS-CPL) originating from the residual luminescence of PtTPBP. Remarkably, fine-tuning the ratio between the two annihilators allows the TTA-UC system to exhibit multicolor CPL emission with an amplified luminescence dissymmetry factor (glum, reaching up to 0.6). Our study unveils a previously unreported "one-excitation-to-three-emissions" system and provides a versatile strategy for modulating CPL emissions, surpassing conventional methodologies. [ABSTRACT FROM AUTHOR]

Solid materials with dynamically tunable circularly polarized luminescence (CPL) feature higher security levels and device-friendly characteristics, showing great superiority in the field of information technology and anti-counterfeiting. To address the limited photoisomerization of fluorescent photoswitch in CPL-active solid materials, here a cholesteric liquid crystal elastomer (CLCE) containing a hydrogen-bonded (H-bonded) polymerizable fluorescent switch AHBA-PSD is prepared. Owing to the good flexibility and low glass-transition temperature of CLCE, AHBA-PSD shows a fast and fully reversible photocyclization/cycloreversion with fluorochromic behavior in CLCE. Further, by controlling the spectral overlapping area between the emission and reflection bands, the CLCE exhibits a strong CPL with a glum value of up to 0.76 accompanied by a reversible phototunable CPL signal. Meanwhile, the H-bond helps to stabilize the mechanical property, and the force-induced switching-off of CPL signal could be achieved due to the destroyed helical structures by external force. Finally, an automatically-recognized identification card with abundant chiroptical information is demonstrated. [ABSTRACT FROM AUTHOR]

Highly symmetrical and aesthetically pleasing molecules have attracted the attention of organic chemists. We synthesized new highly symmetric stereogenic π-conjugated macrocycles with planar or axial chirality. Macrocyclic oligomers synthesized by Yamamoto coupling or Suzuki–Miyaura cross-coupling from the π-unit containing chirality. These cyclization reactions gave multiple oligomers in relatively high yields. We then elucidated their structures and investigated their chiroptical properties, including circular dichroism (CD) and circularly polarized luminescence (CPL). Because of the selection rule for rigid and symmetric structures, these macrocycles exhibit a high dissymmetry factor (gabs or glum) for circularly polarized light in CD or CPL. Several rigid cyclic compounds retain a highly symmetric structure in the excited state and exhibit higher glum values than common chiral organic compounds. This Account provides a brief background regarding chiroptical properties, followed by a summary of the various macrocycles synthesized in this study. We are glad if this Account will be a source of ideas not only for chemists working with π-conjugated compounds, but also for synthetic chemists working with chiral compounds, especially those engaged in asymmetric synthesis. 1 Introduction 2 Brief Description of Chiroptical Properties 3 Stereogenic Macrocycle Based on [2.2]Paracyclophane 3.1 Stereogenic Double-decker Oligothiophene 3.2 Stereogenic Biselenophene Macrocycle 3.3 Helical Oligophenylene Linked with [2.2]Paracyclophane 4 Stereogenic Macrocycle Based on Binaphthyl 4.1 Cyclic Oligomer of Chiral Binaphthyl 4.2 Doubly Twisted Binaphthyl Dimer 4.3 Cyclic Oligomer of Binaphthyl Extended with Paraphenylene 4.4 Curved Helical Paraphenylene Anchoring Chiral Binaphthyl 4.5 Binaphthyl-Hinged [5]-Helicene 5 Summary [ABSTRACT FROM AUTHOR]

A homologous series of 4,7‐bis(aryl) substituted benzothiadiazole (BTD) compounds, containing the helicenic derivatives bis([4]helicene), bis([5]helicene) and bis([6]helicene), have been prepared upon a double Suzuki coupling between 3,6‐bis(pinacolyl‐borane)‐BTD and the corresponding bromo‐aryl precursors. The single crystal X‐ray structure of the bis([4]helicene) compound shows the existence of both helicities (M) and (P) on the same molecule. All the compounds of the series are highly emissive in solution, with quantum yields of the emission ranging from 50 to 91 %. The enantiopure compounds (M,M) and (P,P) for the BTD‐bis([6]helicene) have been prepared from the corresponding enantiopure 2‐bromo‐[6]helicene precursors. Their chiroptical properties have been investigated in correlation with density functional theory (DFT) calculations, which allowed to confidently assign the absolute configuration of the helicene arms and to characterize the different electronic transitions, including the low energy charge transfer excitation from helicenes to BTD. The enantiomerically pure fluorophores (M,M)‐ and (P,P)‐BTD‐bis([6]helicene), which exist in solution as two main conformers, according to the DFT calculations, show CPL activity in solution, with glum factors of ≈1.7×10−3 at λem=525 nm, and also in the solid state, with glum factors of ≈1.2×10−3 in spite of the strong decrease of the quantum efficiency. [ABSTRACT FROM AUTHOR]

Since their discovery, [2.2]paracyclophane (pCp) and its derivatives have fascinated the scientific community due to their original molecular architecture and unusual electronic behavior. Over the years, significant efforts have been devoted to the development of substituted pCps for a variety of applications in different fields, ranging from organic synthesis and asymmetric catalysis to polymer chemistry and material science. This review describes a series of useful approaches that allow chemists to selectively decorate pCps, control the planar chirality that these molecules can display as soon as they are functionalized, and tune their photophysical behaviors. For each of these aspects of paracyclophane chemistry, selected examples of major advances are presented, and possible directions for future research are outlined. The application of pCp as central core for the development of uncommon 3D luminophores is finally highlighted. Emphasis is placed on the potential use of planar chiral luminescent paracyclophanes as antennas or ligands for the design of multifunctional lanthanide complexes, a quite underdeveloped but highly promising area for future research endeavors. [ABSTRACT FROM AUTHOR]

Recently, the potential circularly polarized luminescence (CPL) property of chiral 2D organic–inorganic hybrid perovskites has garnered attention due to their strong stability. However, the photoluminescence (PL) intensity of chiral 2D perovskite is generally low, which undoubtedly limits its development. Therefore, improving the PL and CPL intensity of chiral 2D perovskite has become an important focal point. To overcome this problem, a series of Mn2+‐doped R/S‐(MPEA)2PbBr4 thin films is successfully synthesized. The Mn2+‐doped films can produce strong orange emission under UV excitation with the highest photoluminescence quantum yield (PLQY) of 37.37%, a high value among reported chiral 2D perovskites. Moreover, all Mn: (R/S‐MPEA)2PbBr4 films show symmetric CPL signals. The flexible regulation of CPL is meaningful for applications, which is generally lacking in current studies. Here, it is found that the strength of CPL can be effectively regulated by doping guanidine (Gua), and the maximum glum value of 1.4 × 10−2 and PLQY of 51.31% is achieved, which are the highest among reported chiral 2D perovskites. This work provides a new idea for the development of CPL‐active materials and lays the foundation for spin devices based on chiral hybrid 2D perovskite. [ABSTRACT FROM AUTHOR]

Flexible circularly polarized luminescence (CPL) exhibits significant potential for applications in smart wearable devices and high‐end anti‐counterfeiting. However, existing technologies suffer from low dissymmetry factor (glum) and poor mechanical reliability. Here, a metal halide perovskite is employed as the emitter to construct efficient and robust flexible CPL films through a facile strategy of bilayer stacking, which comprises a layer of perovskite nanocrystalline embedded polymer film and a layer of photonic crystal film based on polymerized chiral liquid crystals (LCs). The photoluminescence efficiency of perovskite nanocrystals in polyacrylonitrile (PAN) matrix is improved by incorporating an appropriate amount of phenylethylammonium bromide (PEABr) as a passivation agent, and the helical arrangement and optical activity of free‐standing flexible photonic crystal films are found to be highly related to the supporting substrates. Upon stacking, the resulting flexible composite film exhibits extremely high |glum| values of up to 1.81, representing the highest value among reported flexible CPL‐active films. Moreover, the composite films demonstrate remarkable mechanical robustness, which shows negligible degradation in terms of glum value even after 1000 bending cycles at a bending radius of 2 mm. Based on the flexible CPL‐active films, advanced anti‐counterfeit labels with switchable patterns under circular polarizers are demonstrated. [ABSTRACT FROM AUTHOR]

Developing efficient blue/deep‐blue circularly polarized organic light‐emitting diodes (CP‐OLEDs) with small efficiency roll‐off remains a great challenge for wide color gamut and high contrast 3D displays. Here, two pairs of chiral stable enantiomers, (R/S)‐PPI‐OBN‐CN and (R/S)‐PyI‐OBN‐CN, composed of imidazole derivatives phenanthroimidazole (PPI) and pyrenoimidazole (PyI) donors, and chiral group of (R/S)‐octahydro‐binaphthol (OBN‐CN) acceptor are designed. These new blue/deep‐blue molecular architectures exhibit excellent thermal and electrochemical stabilities, hybrid local and charge transfer (HLCT) excited state, and clear CPL characteristics with dissymmetry factors (|gPL|) of 1.57 × 10−3/2.49 × 10−3 in the neat films. Moreover, the CP‐OLEDs based on (R/S)‐PPI‐OBN‐CN and (R/S)‐PyI‐OBN‐CN exhibit the deep‐blue/pure‐blue emission with the CIE coordinates of (0.15, 0.08) and (0.15, 0.14), the maximum external quantum efficiencies (EQEs) of 7.25% and 8.11% and very small efficiency roll‐offs of 17.6% and 1.8% at the luminescence of 1000 cd m−2, respectively. Even when the brightness is increased to 10000 cd m−2, (R/S)‐PyI‐OBN‐CN‐based device could still maintain as high as 6.68%. Obvious circularly polarized electroluminescence (CPEL) activities with the EL dissymmetry factors (gEL) of +1.54 × 10−3/−1.63 × 10−3 and +1.95 × 10−3/−1.72 × 10−3 are also recorded. These are the first highly efficient blue/deep‐blue CP‐OLEDs based on “hot exciton” enantiomers. [ABSTRACT FROM AUTHOR]

Although helicenes are promising molecules, the synthetic difficulty and tediousness have often been problems, and only small amounts of optically pure helicenes have been obtained by using chiral HPLC in most cases. Herein, aza[7]helicenes or closed‐aza[7]helicenes with (1R)‐menthyl substituents were selectively synthesized via the intramolecular Scholl reaction, and the diastereomeric pairs were separated by silica gel column chromatography. The optically pure helicenes were further transformed into the corresponding cyclic dimers, and the chiroptical properties were investigated. The rigid π‐frameworks of the dimers led to the high molar extinction coefficients and fluorescence quantum yields, while the twisted helicene moieties induced clear Cotton effects and CPL in the visible region, and the high CPL brightness (BCPL) was achieved. Furthermore, the cyclic dimers were found to have the macrocyclic cavity with the two NH groups suitable for the selective binding of a fluoride anion, which induced significantly redshifted fluorescence and CPL in the red region. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescence (CPL) materials offer exciting potential due to their unique light properties. However, controlling the color of afterglow emission, a key feature for many applications remains a challenge. Here, a co‐doping strategy is presented for precise control of multicolor CPL afterglow in films. This approach utilizes chiral naphthylphosphoric acid derivatives as energy and chirality transfer donors, commonly used fluorescent dye rhodamine B (RB) and PVA are selected as the acceptor and the polymeric matrix, respectively. Remarkably, the co‐doped films exhibit ultra‐long green circular polarization phosphorescence lasting several seconds with high efficiency (14.23%), lifetime (1025.5 ms), and dissymmetry factor (8.44 × 10−3). Crucially, by adjusting the acceptor content, it can precisely tune the phosphorescence‐to‐fluorescence ratio and achieve multicolor afterglow. This control stems from a combination of Förster resonance energy transfer, chirality transfer, and color‐mixing effects. Furthermore, this approach significantly improves the asymmetry factor of the CPL afterglow by an order of magnitude (5.17 × 10−2). It is anticipated that this straightforward approach to precisely regulating the afterglow color of CPL will provide invaluable insights for the future design of highly efficient and innovative CPL materials. [ABSTRACT FROM AUTHOR]

Chirality, a fundamental principle in chemistry, biology, and medicine, is prevalent in nature and in organisms. Chiral molecules, such as DNA, RNA, and proteins, are crucial in biomolecular synthesis, as well as in the development of functional materials. Among these, 1,1′‐binaphthyl‐2,2′‐diol (BINOL) stands out for its stable chiral configuration, versatile functionality, and commercial availability. BINOL is widely employed in asymmetric catalysis and chiral materials. This review mainly focuses on recent research over the past five years concerning the use of BINOL derivatives for constructing chiral macrocycles and cages. Their contributions to chiral luminescence, enantiomeric separation, transmembrane transport, and asymmetric catalysis were examined. [ABSTRACT FROM AUTHOR]

Chiral lead halide perovskites have captivated considerable attentions due to their distinctive attributes, such as ferroelectricity, spin‐dependent transport, and chiroptical activity. However, lead toxicity and weak circularly polarized luminescence (CPL) have cast a pall over their practical applications. Here, a series of 0D lead‐free chiral enantiomorphic hybrids, such as (R‐/S‐MBA)3In1‐xSbxCl6 (x = 0–1) is successfully developed. By optimizing the Sb3+ doping concentration to 0.55%, the resultant (R‐/S‐MBA)3In99.45%Sb0.55%Cl6 not only shows a near‐unity quantum yield but also emanates potent CPL, boasting a dissymmetry factor (glum) of 6.3 × 10–3. These efficient CPL activities are intricately tied to the presence of a twisted luminescent cluster [SbCl6]3– induced by structural chirality. The comprehensive results reveal that the emission of the chiral perovskite originated from self‐trapped excitons (STEs) of 5s2 Sb3+ ions. Moreover, (MBA)3In99.45%Sb0.55%Cl6 single crystals also exhibit bright orange emission and UV detector signals. These findings will pave the way for the further investigation in efficient CPL and detectors based on lead‐free chiral optoelectronic materials. [ABSTRACT FROM AUTHOR]

Chiral organic‐inorganic hybrid perovskites (OIHPs) exhibit exceptional optical and chiral properties, demonstrating potential for 3D display, circularly polarized light‐emitting diodes (CP‐LEDs), and CPL switches. However, the construction of chiral OIHPs often relies on chiral building blocks, limiting chemical diversity, and possessing challenges in achieving large asymmetry factor (glum) without sacrificing photoluminescence quantum yield (PLQY). Here, Chiral DMA4In1‐xSbxCl7 (DMA = dimethylammonium, x = 0 to 1) with superior circularly polarized luminescence (CPL) are successfully constructed based on achiral building blocks DMA+ and metal halides. By optimizing the Sb3+ content, bright white emission with a high PLQY of 69.13% is achieved, as well as near‐unity PLQY yellow emission and strong CPL signals with a glum of up to +1.40 × 10−2, exhibiting a performance comparable to state‐of‐the‐art chiral OIHPs. Combining optical characterizations and theoretical calculations reveal that these intriguing properties originate from the intrinsic chiral helical structures and a pair of perfect complementary color emissions in DMA4In1‐xSbxCl7. In addition, DMA4In1‐xSbxCl7 exhibit excellent thermal stability and mild thermal quenching in the temperature range of 300 to 420 K. These fascinating properties suggest that DMA4In1‐xSbxCl7 have significant applications in white light‐emitting diodes (WLED), 3D displays and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

A family of chiral perylene diimides (PDIs) was newly developed as excellent circularly polarized luminescence (CPL) materials. They are asymmetrically derivatized with a double‐alkyl‐chained L‐ or D‐glutamate unit and a linear or branched alkyl chain. When water is added to the tetrahydrofuran (THF) solution of glutamate‐PDI‐linear‐alkyl chain compounds, kinetically formed H‐aggregates are formed in globular nanoparticles (NPs). These NPs undergo spontaneous transformation into thermodynamically stable nanotubes via helical nanostructures, which showed structured broad spectra originating from the strong coupling of delocalized Frenkel excitations (FE) and charge transfer excitations (CTE). Significant enhancement of circular dichroism (CD), fluorescence quantum yield, and circularly polarized luminescence (CPL) with luminescence dissymmetry factor (glum) are observed during the transformation of NPs to the FE/CTE‐coupled helical and tubular structures. This transformation process is significantly accelerated by applying physical stimuli, i.e., ultrasonication or adding helical aggregates as seed crystals, a feature unique to living supramolecular polymerization. Meanwhile, the branched chain‐containing PDIs only form H‐aggregates and did not show FE/CTE hybrid exciton states with living supramolecular polymerization properties. This study unveils that suitably designed chiral PDI derivatives show FE/CTE coupling accompanied by high fluorescence quantum yields, enhanced chiroptical properties, and supramolecular living polymerization characteristics. [ABSTRACT FROM AUTHOR]

Herein, it is reported that lyotropic liquid crystals that transfer carbon‐centered chirality to helical chirality and subsequently to macroscopic chirality in the mesophases. This process is accompanied by remarkable amplification of both emission quantum yield and dissymmetry factor of the circularly polarized luminescence (CPL). Cationic tridentate cyclometalated Pd(II) complexes, once functionalized with chiral hydrogen‐bonding motifs of amide, aggregated into head‐to‐tail dimers at low concentrations in acetonitrile and further self‐organized into chiral lyotropic chromonic mesophases upon concentrated to 50 wt.%. At 25 °C, the chiral chromonics display metal–metal‐to‐ligand charge‐transfer (MMLCT) phosphorescence at an emission maximum of 677 nm with quantum yields up to 38% and lifetimes up to 0.50 µs. Notably, the dissymmetry factors ranged from 0.10 to 0.76, varying with the sample thickness in the range of 200–15 µm. Comparison studies and theoretical calculations reveal that the hydrogen‐bonding amide group is pivotal for the formation of the staggered configuration in the helical superstructures. Additionally, the carbon‐centered chirality of the amide dictate the handedness of the helices and consequently influenced the properties of CPL. [ABSTRACT FROM AUTHOR]

Photochromic circularly polarized luminescence (CPL) demonstrates broad application prospects in the field of advanced functional materials. However, the current photochromic CPL focuses predominantly on single‐band CPL adjustment, and how to achieve dynamically tunable CPL in multi‐band is still highly challenging. This work reports the success in utilizing reversible photochromism for realizing full‐color CPL emission. Photochromic flexible films are created consisting of triple components: spiropyran (SP) working as photochromic matter, polyurethane (PU) as matrix, and chiral helical polyacetylene as chiral component. Further introducing blue fluorophore 9‐anthracene carboxylic acid (ACA) in the film, blue CPL and red CPL are emitted respectively through selective absorption/transmission and circularly polarized fluorescence energy transfer (CPF‐ET). Doping the photochromic film with diverse fluorophores provides full‐color CPL emission. Adding Zn2+ further intensifies fluorescence and CPL via forming merocyanine (MC)‐Zn2+ complex. Taking advantage of the diverse fluorescence and CPL emission, anti‐counterfeiting, and secondary encryption application of the resulting photochromic CPL materials are demonstrated. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescence (CPL) active materials have attracted widespread attention because of their potential applications. Nonetheless, it is still a great challenge to fabricate CPL materials with both high fluorescence quantum efficiency (Φ) and high luminescent asymmetry factor (glum). According to the unique structure characteristics of chiral layered metal–organic frameworks (CLMOFs), herein a novel strategy to construct high‐performance CPL materials, by utilizing the confinement effect of CLMOFs is developed. Conjugate dye molecules, such as fluorescent brighteners, fluorescein, and rhodamine B, which are readily subjected to aggregation‐caused quenching (ACQ) effect, are successfully intercalated into CLMOF matrix, affording blue, yellow–green, and red CPL, respectively. Both high Φ and glum values of up to 91% and 0.069 are obtained, owing to the distinct confinement effect of CLMOFs. After confining dye molecules within CLMOF, the ACQ effect is effectively inhibited, which is beneficial for fluorescence enhancement; simultaneously, the chirality transfer from CLMOF matrix to dyes by controlling their arrangement in the chiral confinement microenvironment, leading to the high glum values. Based on the full‐color and strong CPL, a multi‐dimensional code system is proposed. This work paves a new avenue to design and assemble CPL materials with high Φ and glum, which can be widely adopted. [ABSTRACT FROM AUTHOR]

Functional materials that exhibit circularly polarized luminescence (CPL) have shown immense potential in applications such as 3D optical displays and advanced information encryption. However, facile and efficient regulation of the multiple emission properties in chiral systems has remained a challenge due to the scarcity of suitable materials and the complexity of the systems. Herein, a multiple CPL regulation platform is fabricated by the helical co‐assembly of an aldehyde‐functionalized fluorane dye (Rhodol‐CHO, 6′‐(diethylamino)‐3′‐hydroxy‐3‐oxo‐3H‐spiro[isobenzofuran‐1,9′‐xanthene]‐4′‐carbaldehyde) and chiral liquid crystals, which can efficiently combine multiple stimuli‐responsive characteristics and high optical activity. By introducing acid, base, and compounds containing primary amino (─NH2) groups, the CPL property of the system can be easily modified. The obtained CPL systems exhibit apparent asymmetry, with glum values reaching 0.54–0.75). Further, these CPL modules are successfully applied in multi‐mode information encryption, highlighting their practical utility. Therefore, this study presents a novel strategy for developing materials with diverse CPL behaviors based on a simple‐designed platform, advancing further applications of CPL materials. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescence (CPL)‐active materials are increasingly recognized for their potential applications such as 3D imaging, data storage, and optoelectronic devices. Typically, CPL materials have required high‐energy (HE) photons for excitation to emit low‐energy (LE) circularly polarized light, a process known as downshifting CPL (DSCPL). However, the emergence of upconverted CPL (UCCPL), where the absorption of multi LE photons results in the emission of a single HE photon with circular polarization, has recently attracted considerable attention. This minireview highlights the intricate relationship between upconversion and CPL phenomena. During upconversion, the dissymmetry factor (glum) value can be improved in certain systems. Additionally, the integration of both LE and HE photons in upconversion‐downshifting‐synergistic systems offers avenues for dual‐excitation or dual‐emission CPL functionalities. More in detail, the emerging UCCPL based on various photon upconversion mechanisms and their synergy with DSCPL are introduced. Additionally, several examples that demonstrate the applications of UCCPL are presented to highlight the future opportunities. [ABSTRACT FROM AUTHOR]

Boron‐doped helicenes, known for their unique electronic and photophysical properties, are of great interest for numerous applications. This research introduces two new azabora[6]helicenes, H[6]BN1 and H[6]BN2, synthesized through an efficient method. These molecules have boron and nitrogen atoms in opposing positions, enhancing their distinctive attributes. Both helicenes show excellent emission properties, with H[6]BN1 and H[6]BN2 exhibiting narrowband blue fluorescence and circularly polarized luminescence (CPL), achieving glum values of 4~5×10−4 which is beneficial for chiroptical applications. The addition of a donor group, 3, 6‐di‐tert‐butyl‐9H‐carbazole, in H[6]BN2 improves luminescence, likely due to enhanced molecular orbital overlap and electron delocalization. H[6]BN1′s needle‐like single crystals exhibit mechanochromism, changing luminescent color from yellow to green under mechanical stress, which is promising for stimulus‐responsive materials. In conclusion, this study presents a novel class of BN[6]helicenes with superior chiroptical properties. Their combination of electronic features and mechanochromism makes them ideal for advanced chiroptical materials, expanding the potential of helicene‐based compounds and offering new directions for the synthesis of molecules with specific chiroptical characteristics. [ABSTRACT FROM AUTHOR]

Out‐of‐plane polarization is a highly desired property of two‐dimensional (2D) ferroelectrics for application in vertical sandwich‐type photoferroelectric devices, especially in ultrathin ferroelectronic devices. Nevertheless, despite great advances that have been made in recent years, out‐of‐plane polarization remains unrealized in the 2D hybrid double perovskite ferroelectric family. Here, from our previous work 2D hybrid double perovskite HQERN ((S3HQ)4EuRb(NO3)8, S3HQ=S‐3‐hydroxylquinuclidinium), we designed a molecular strategy of F‐substitution on organic component to successfully obtain FQERN ((S3FQ)4EuRb(NO3)8, S3FQ=S‐3‐fluoroquinuclidinium) showing circularly polarized luminescence (CPL) response. Remarkably, compared to the monopolar axis ferroelectric HQERN, FQERN not only shows multiferroicity with the coexistence of multipolar axis ferroelectricity and ferroelasticity but also realizes out‐of‐plane ferroelectric polarization and a dramatic enhancement of Curie temperature of 94 K. This is mainly due to the introduction of F‐substituted organic cations, which leads to a change in orientation and a reduction in crystal lattice void occupancy. Our study demonstrates that F‐substitution is an efficient strategy to realize and optimize ferroelectric functional characteristics, giving more possibility of 2D ferroelectric materials for applications in micro‐nano optoelectronic devices. [ABSTRACT FROM AUTHOR]

The dynamic regulation of circularly polarized luminescence (CPL) holds profound significance in various fields, such as high-level information storage and encryption. Here we developed a chiral amphiphilic molecule, CPSB-GLU-PEG350 (CGP), composed of aggregation-induced emission (AIE) chromophores (Z)-4-(1-cyano-2-phenylvinyl)benzoic acid (CPSB), a chiral linker Glutamic acid and polyethylene glycol (PEG) thermoresponsive segments. Within the self-assembled supramolecular system formed by CGP, we have achieved in-situ temperature-responsive chiral structures, facilitating the thermal control switch of the CPL signal. Molecular dynamics simulations demonstrate the distinct behaviors of AIE and PEG units during the temperature-variable assembly process. Furthermore, by co-assembling achiral dye molecules with CGP, we have expanded the color range of the temperature-responsive CPL assembly system in situ and confirmed the occurrence of circularly polarized-Förster resonance energy transfer (C-FRET) phenomenon in this process, which successfully enriched the strategies for in-situ CPL control in aqueous phases. In addition, the contactless radiative energy transfer of CPL can also be realized in this system, exhibiting more flexible temperature regulation of the CPL signal. This study provides a convenient and universal strategy for the construction of dynamically smart chiroptical materials. [ABSTRACT FROM AUTHOR]

Achieving strong circularly polarized luminescence (CPL) responses in chiral inorganic materials is a challenge. Our study reports a synthesis of bismuth bromide oxybate-based inorganic nanomaterials that have been modified with chiral sugar alcohols (D/L-BYE) co-doped with Er3+ and Yb3+. Chiral molecules are used as inducers to preferentially grow the materials towards specific chirality. The Er3+, Yb3+ co-doped chiral sugar alcohol modified BiOBr has stronger luminescence intensity of up-conversion and the near-infrared second region (NIR II) under the excitation of 980 nm. It has been demonstrated that the enhancement of near-infrared and visible luminescence is attributable to electromagnetic field-induced acceleration of radiative excursion and Mie scattering effects. The study proposes a novel approach to simultaneously enhance the up/down conversion luminescence of chiral inorganic nanomaterials doped with rare earth ions. Meanwhile, this material exhibits strong circularly polarized luminescence properties in the visible range, which has great application potential in chiral optics and other fields. [ABSTRACT FROM AUTHOR]

Lighting systems with circularly polarized luminescence (CPL) are an emerging field with high hopes in, for example, neural cell circuits and encoding applications. The major challenges that forfeits their real‐world application are i) the design of chiroptical materials (CMs) with high CPL brightness (BCPL; today's record is Eu‐based compounds with average 287 M−1cm−1, while 90% of other CMs show <150 M−1cm−1 in solution) and ii) how to keep CPL response in films/coatings of technological relevance. Since natural evolution is driven by chiral selectivity at the supramolecular level, fluorescent proteins (FPs) are ideal candidates to provide large BCPL spanning visible and near‐infrared regions. This hypothesis is confirmed for all the known FP classes, demonstrating high emission intensities (photoluminescence quantum yields (ϕ) up to 76%) and record average BCPL of |200| M−1cm−1 (solution). What is more, the CPL response is also kept in polymer coatings. It is rationalized that structural factors (chromophore rigidity, surrounding amino acids, supramolecular packaging, and exciton coupling) hold a significant influence, regardless of the ϕ values. Finally, proof‐of‐concept CPL‐encoded signals in monochromatic/white hybrid light‐emitting diodes with FP‐polymer filters show exceptional stabilities. Overall, this work stands out FPs toward a new CM family, in general, and biogenic CPL‐encoded lighting systems, in particular. [ABSTRACT FROM AUTHOR]

Molecular chirality plays a pivotal role across the disciplines of chemical and physical sciences, as well as holding significant implications in the realms of medicine and technology. Chiral macrocycles have attracted recent interests in synthetic chemistry, material science, and supramolecular chemistry. Due to the cyclic arrangements of stereogenic elements or special orientations confined in the rigid structures, π‐conjugated chiral macrocycles are expected to be highly luminescent, and configurationally stable, and thus serve to develop high‐performance chiroptical materials. Given the rapid progress achieved in this new area in recent years, it is significant to highlight new concepts and breakthroughs. This minireview will offer the overview of a wide range of π‐conjugated chiral macrocycles from traditional molecules which include the axially, helically, and planar chiral skeletons to the new chiral nanobelts with a focus on the structure‐function relationship between chiral molecules and the unique chiroptical properties. [ABSTRACT FROM AUTHOR]

A pair of enantiopure [6]‐azairidahelicenes incorporating chirality at the metal center and on the helicenic ligand were synthesized by dynamic kinetic resolution (dkr) of a configurationally labile [4]‐helicenic ligand (4‐(2‐pyridyl)‐benzo[g]phenanthrene, L1H) using bis‐cyclometalated chiral‐at‐metal only iridium(III) precursors as chiral inductors. The origin of the observed dkr is attributed to the different conformation and stability of diastereomeric reaction intermediates formed during the cyclometalation process. The isolated enantiomers exhibited circularly polarized phosphorescence (CPP), with |gphos| values of 1.8×10−3. [ABSTRACT FROM AUTHOR]

Ultraviolet circularly polarized luminescence (UV‐CPL) with high photon energy shows great potential in polarized light sources and stereoselective photopolymerization. However, developing luminescent materials with high UV‐CPL performance remains challenging. Here, we report a pair of rare earth Ce3+‐based zero‐dimensional (0D) chiral hybrid metal halides (HMHs), R/S‐(C14H24N2)2CeBr7, which exhibits characteristic UV emissions derived from the Ce 5d–4f transition. The compounds show simultaneously high photoluminescent quantum yields of (32–39)% and large luminescent dissymmetry factor (|glum|) values of (1.3–1.5)×10−2. Thus, the figures of merits of R/S‐(C14H24N2)2CeBr7 are calculated to be (4.5–5.8)×10−3, which are superior to the reported UV‐CPL emissive materials. Additionally, nearly 91 % of their PL intensities at 300 K can be well preserved at 380 K (LED operating temperature) without phase transition or decomposition, demonstrating the excellent structural and optical thermal stabilities of R/S‐(C14H24N2)2CeBr7. Based on these enantiomers, the fabricated UV‐emitting CP‐LEDs exhibit high polarization degrees of ±1.0 %. Notably, the UV‐CPL generated from the devices can significantly trigger the enantioselective photopolymerization of diacetylene with remarkable stereoselectivity, and consequently yield polymerized products with the anisotropy factors of circular dichroism (gCD) up to ±3.9×10−2, outperforming other UV‐CPL materials and demonstrating their great potential as UV‐polarized light sources. [ABSTRACT FROM AUTHOR]

Tunable circularly polarized luminescence (CPL) has attracted substantial research interest. Till date, the main methods for adjusting CPL is by changing the ratio of fluorescent components and/or regulating external stimuli. Although these adjustment methods have been demonstrated to be reliable, most of them show disadvantages including challenging molecular design, complicated and cumbersome material fabrication, and rigorous adjustment conditions. Herein, the "Surface‐Filming Assembly" (SFA) strategy for conveniently and efficiently modulating CPL by taking the perovskite/chiral helical polyacetylene system as a model is proposed and established. This strategy can facilely achieve multicolor CPL by simply changing the color (or number) of perovskite fluorescent layers and/or the attaching order of the perovskite layers in the assembled multilayer film. Compared with previously reported methods, the SFA strategy integrates the preparation process and adjustment in one single step, simplifying the preparation process (especially the preparation of perovskite with different ratios of halogen atoms) and making adjustment simple and efficient. The SFA strategy and different CPL generation mechanisms to achieve multicolor and white‐color emission with glum up to 10−2 are combined. Based on the CPL film and the solvent sensitivity of perovskite, a solvent‐responsive CPL‐emitting switch and further applied the CPL sample in multiple information displays and encryption are realized. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescence (CPL)‐active molecular materials have drawn increasing attention due to their promising applications for next‐generation display and optoelectronic technologies. Currently, it is challenging to obtain CPL materials with both large luminescence dissymmetry factor (glum) and high quantum yield (Φ). A pair of enantiomeric N N C‐type Pt(II) complexes (L/D)‐1 modified with chiral Leucine methyl ester are presented herein. Though the solutions of these complexes are CPL‐inactive, the spin‐coated thin films of (L/D)‐1 exhibit giantly‐amplified circularly polarized phosphorescences with |glum| of 0.53 at 560 nm and Φair of ~50 %, as well as appealing circular dichroism (CD) signals with the maximum absorption dissymmetry factor |gabs| of 0.37–0.43 at 480 nm. This superior CPL performance benefits from the hierarchical formation of crystalline fibrillar networks upon spin coating. Comparative studies of another pair of chiral Pt(II) complexes (L/D)‐2 with a symmetric N C N coordination mode suggest that the asymmetric N N C coordination of (L/D)‐1 are favorable for the efficient exciton delocalization to amplify the CPL performance. Optical applications of the thin films of (L/D)‐1 in CPL‐contrast imaging and inducing CP light generation from achiral emitters and common light‐emitting diode lamps have been successfully realized. [ABSTRACT FROM AUTHOR]