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Compact luminophores with long emission wavelengths have aroused considerable theoretical and practical interest. Organics with room-temperature phosphorescence (RTP) are also desirable for their longer lifetimes and larger Stokes shifts than fluorescence. Utilizing the low electronic transition energy intrinsic to thiocarbonyl compounds, electron-withdrawing groups were attached to the 4H-pyran-4-thione core to further lower the excited state energies. The resulting mini-phosphors were doped into suitable polymer matrices. These purely organic, amorphous materials emitted near-infrared (NIR) RTP. Having a molar mass of only 162 g mol -1 , one of the phosphors emitted RTP that peaked at 750 nm, with a very large Stokes shift of 15485 cm -1 (403 nm). Thanks to the good processability of the polymer film, light-emitting diodes (LEDs) with NIR emission were easily fabricated by coating doped polymer on ultraviolet LEDs. This work provides an intriguing strategy to achieve NIR RTP using compact luminophores., (© 2024 Wiley-VCH GmbH.)

Afterglow materials have garnered significant interest due to distinct photophysical characteristics. However, it is still difficult to achieve long afterglow phosphorescence from organic molecules due to aggregation-caused quenching (ACQ) and energy dissipation. In addition, most materials reported so far have long afterglow emission only at room or even low temperatures, and mainly use UV light as an excitation source. In this work, we report a strategy to achieve high temperature long afterglow emission through the assembly of isolated 0D metal-organic cages (MOCs). In which, both ACQ and phosphorescence quenching effects are effectively mitigated by altering the stacking mode of organic chromophores through orthogonally anchoring into the edges of cubic MOCs. Furthermore, improvement in molecular rigidity, promotion of spin-orbit coupling and broadening of the absorption range are achieved through the MOC-engineering strategy. As a result, we successfully synthesized MOCs that can produce afterglow emission even after excitation by WLEDs at high temperatures (380 K). Moreover, the MOCs are capable of generating afterglow emissions when excited by mobile phone flashlight at room temperature. Given these features, the potential applications of MOCs in the visual identification of explosives, information encryption and multicolor display are explored., (© 2024 Wiley-VCH GmbH.)

The synthesis, crystal structure and room-temperature phosphorescence (RTP) of a 2D metal-free inorganic covalent framework ((H 2 en) [B 5 O 8 (OH)], named as CityU-12, and en represents for ethylenediamine) are reported. The precise structure information of CityU-12 has been disclosed through both single-crystal X-ray diffraction (SCXRD) analysis and low-dose high-resolution transmission electron microscopy (LD-HRTEM) study. The SCXRD results show that CityU-12 composes of 2D anionic B─O-based covalent inorganic frameworks with protonated ethylenediamine locating in the pore sites of 2D B─O layers while LD-HRTEM suggests that CityU-12 has an interplanar distance of 0.60 nm for (00 2 ¯ $\bar{2}$ ) crystal plane and 0.60 nm for (10 1 ¯ $\bar{1}$ ) crystal plane. The optical studies show that CityU-12 is an excellent nonconventional RTP material with the emission peak at 530 nm and a lifetime of 1.5 s. The quantum yield is 84.6% and the afterglow time is as long as 2.5 s. This work demonstrates that metal-free B─O frameworks can be promising nonconventional phosphors for RTP., (© 2024 Wiley‐VCH GmbH.)

The long-lived room-temperature phosphorescence (RTP) originating from thiophene boronate polyvinyl alcohol (PVA) has enabled the creation of metal-ion-responsive RTP films doped with spirolactam ring-containing rhodamine 6G ( 1 ). In this study, RTP-active PVA films, namely, TDB@PVA and ATB@PVA , were prepared through boronate esterification of thiophene-2,5-diboronic acid ( TDB ) and 5-acetylthiophene-2-boronic acid ( ATB ) with the diol units of PVA. The delayed emission properties were evaluated, revealing an emission band at 477 nm with a turquoise afterglow for TDB@PVA and at 510 nm with a green afterglow for ATB@PVA after UV light irradiation ceased. The photophysical properties were assessed using TD-DFT and DFT calculations at the B3LYP/cc-pVDZ level. N -(rhodamine-6G)lactam dye with a salicylimine unit ( 1 ) was doped into the RTP-based PVA films, producing a multicolored afterglow upon the addition of metal ions. This phenomenon is explained by a triplet-to-singlet Förster-type resonance energy transfer process from the cross-linked thiophene boronate in PVA to the metal-ion-activated colored form of 1 . This photophysical feature finds applicability in encryption techniques. Notably, the reversible metal-ligand coordination of 1 in the PVA system enabled a write/erase information process., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Maida, Sugawara, Suzuki, Ito and Kubo.)

Room-temperature phosphorescent carbon dots (RTP-CDs) have received increasing attention due to their excellent optical properties and potential applications. Nevertheless, the realization of RTP-CDs in aqueous solutions remains a considerable challenge due to the water-molecule- and oxygen-induced deactivation of the triplet excitons, which leads to phosphorescence quenching. In this study, ultralong phosphorescence in water was achieved by in situ self-assembly of CDs encapsulated in a rigid hydrogen-bonded organic framework (HOF). The phosphorescence lifetime reaches an impressive 956.96 ms and exhibits long-lasting optical and structural stability in water for more than 90 days. The composite material not only has ultralong luminescence life and excellent luminescence stability but also has two-color phosphorescence emission, as well as excellent antiphotobleaching and phosphorescence stability in aqueous solution, which can solve the current problem that RTP is easily burst out by water and moisture. In addition, this study introduced a fluorescent dye based on the triplet-singlet Förster resonance energy transfer system (TS-FRET) to fine-tune the afterglow properties. This work will inspire the design of RTP systems with dual phosphor light sources and provide new strategies for the development of smart RTP materials in water.

Purely organic room-temperature phosphorescence (RTP) materials have received intense attention due to their fascinating optical properties and advanced optoelectronic applications. The promotion of intersystem crossing (ISC) and minimalization of nonradiative dissipation under ambient conditions are key prerequisites for realizing high-performance organic RTP; However, the ISC process is generally inefficient for organic fluorogens and the populated triplet excitons are always too susceptible to be well stabilized by conventional means. Particularly, organizing organic fluorophores into compact and ordered entities by supramolecular dynamic interactions has proven to be a newly-emerged strategy to boost the ISC process greatly and suppress the non-radiative relaxations immensely, facilitating the population and stabilization of triplet excitons to access high-performance organic RTP. Consequently, well-defined organic emitters enable robust RTP emission even in the solution state, thus greatly extending the applications. Here, this review is focused on a timely and brief introduction to recent progress in tailoring ordered high-performance RTP emitters by supramolecular dynamic interactions. Their typical preparation strategies, optoelectronic properties, and applications are thoroughly summarized. In the summary section, key challenges and perspectives of this field are highlighted to suggest potential directions for future study., (© 2024 Wiley‐VCH GmbH.)

Nonconventional luminophores have received increasing attention, owing to their fundamental importance, advantages in outstanding biocompatibility, easy preparation, environmental friendliness, and potential applications in sensing, imaging, and encryption. Purely organic molecules with outstanding fluorescence and room-temperature phosphorescence (RTP) have emerged as a new library of benign afterglow agents. However, the cost, toxicity, high reactivity, and poor stability of materials also limit their practical applications. Therefore, some natural products, synthetic compounds, and biomolecules have entered horizons of people. The as-designed exhibits sky blue and green fluorescence emission and green RTP emission (a lifetime of 343 ms and phosphorescence quantum of 15.3%) under air condition. This study presents an organic fluorescence for biological imaging and RTP for anti-counterfeiting and encryption based on amino acids, maleic anhydride and 4-vinylbenzenesulfonic acid sodium salt hydrate. This study provides a strategy for nonconventional luminophores in designing and synthesizing pure organic RTP materials., (© 2024 Wiley‐VCH GmbH.)

Polymeric room-temperature phosphorescence (RTP) materials especially multicolor RTP systems hold great promise in concrete applications. A key feature in these applications is a triplet charge transfer transition. Aromatic electron donors and electron acceptors are often essential to ensure persistent RTP. There is much interest in fabricating non-aromatic charge-transfer-mediated RTP materials and it still remains a formidable challenge to achieve color-tunable RTP via charge transfer. Herein, a charge-transfer-mediated RTP material by embedding quinoline derivatives within a non-aromatic polymer matrix such as polyacrylamide (PAM) or polyvinyl alcohol (PVA) is developed. Through-space charge transfer (TSCT) is achieved upon alkali- or heat treatment to realize a long phosphorescence lifetime of up to 629.90 ms, high phosphorescence quantum yield of up to 20.51%, and a green-to-blue afterglow for more than 20 s at room temperature. This color-tunable RTP emerges from a nonaromatic polymer to single phosphor charge transfer that has rarely been reported before. This finding suggests that an effective and simple approach can deliver new color-tunable RTP materials for applications including multicolor display, information encryption, and gas detection., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Room temperature phosphorescence rarely occurs from pure organic molecules, especially in the solid-state. A strategy for the design of highly emissive organic phosphors is still hard to predict, thus impeding the development of new functional materials with the desired optical properties. Herein, we analyze a family of alkyl and aryl-substituted persulfurated benzenes, the latter representing a class of organic solid-state triplet emitters able to show very high emission quantum yield at room temperature. In this work, we correlate structural parameters with the photophysical properties observed in different experimental conditions (diluted solution, crystalline and amorphous phase at RT and low temperature). Our results, corroborated by a detailed computational analysis, indicate a close relationship between the luminescence properties and i) the nature of the substituents on the persulfurated core, ii) the adopted conformations in the solid state, both in crystalline and amorphous phases. These factors contribute to characterize the lowest-energy lying excited-state, its deactivation pathways, the phosphorescence lifetime and quantum yield. These findings provide a useful roadmap for the development of highly performing purely organic solid-state emitters based on the persulfurated benzene platform., (© 2024 Wiley-VCH GmbH.)

Modulating the stimulus-responsiveness of a luminescent crystal is challenging owing to the complex interdependent nature of its controlling factors, such as molecular structure, molecular conformation, crystal packing, optical properties, and amorphization behavior. Herein, we demonstrate a halogen-exchange approach that disentangles this problem, thereby realizing the modulation of room-temperature phosphorescence-to-phosphorescence mechanochromism. Replacing the bromine atoms in a brominated thienyl diketone with chlorine atoms afforded isostructural crystals; i.e., molecules with different halogen atoms exhibited the same molecular conformation and crystal packing. Consequently, amorphization behavior toward mechanical stimulation was also the same, and the phosphorescence of amorphous states originated from the same conformer of each diketone. In contrast, the phosphorescence properties of each conformer were modulated differently, which is ascribable to heavy atom effects, resulting in the modulation of the mechanochromism. Thus, halogen exchange is a promising approach for modulating the stimulus-responsive photofunctions of crystals involving spin-forbidden processes.

Abstract Ultralong room‐temperature phosphorescence (RTP) is highly useful for information encryption, organic electronics, bioelectronics, etc. However, the preparation of related metal‐free materials with multiple colors across the full spectrum remains a major challenge. Herein, a facile method is developed to fabricate boron‐doped carbon dot (B‐CD) composites with full‐color long lifetime RTP continuously tailorable in the range of 466–638 nm simply by pyrolysis of the citric acid and boric acid precursors with various mass ratios at different temperatures. This leads to the formation of luminescent B‐CD centers in a rigid polycrystalline B2O3 matrix, which effectively stabilizes the triplet excited states of B‐CDs. Thus, the composites become phosphorescent over a relatively long period (5–12 s) after the removal of the irradiation source. Meanwhile, the increased particle size and oxidation degree of B‐CDs obtained at larger citric acid feeding or higher pyrolysis temperature continuously shift the phosphorescence from blue to red. Due to the formation of multiple luminescence centers, the RTP can also be finely modulated by the excitation wavelength. The resulting B‐CD composites with highly tunable long lifetime RTP further allow a variety of distinctive applications in multidimensional encryption handily utilizing space, time, and color variations.

Ultralong room‐temperature phosphorescence (RTP) is highly useful for information encryption, organic electronics, bioelectronics, etc. However, the preparation of related metal‐free materials with multiple colors across the full spectrum remains a major challenge. Herein, a facile method is developed to fabricate boron‐doped carbon dot (B‐CD) composites with full‐color long lifetime RTP continuously tailorable in the range of 466–638 nm simply by pyrolysis of the citric acid and boric acid precursors with various mass ratios at different temperatures. This leads to the formation of luminescent B‐CD centers in a rigid polycrystalline B2O3 matrix, which effectively stabilizes the triplet excited states of B‐CDs. Thus, the composites become phosphorescent over a relatively long period (5–12 s) after the removal of the irradiation source. Meanwhile, the increased particle size and oxidation degree of B‐CDs obtained at larger citric acid feeding or higher pyrolysis temperature continuously shift the phosphorescence from blue to red. Due to the formation of multiple luminescence centers, the RTP can also be finely modulated by the excitation wavelength. The resulting B‐CD composites with highly tunable long lifetime RTP further allow a variety of distinctive applications in multidimensional encryption handily utilizing space, time, and color variations. [ABSTRACT FROM AUTHOR]

Supramolecular polymers with different functionalities have been continuously developed in the past decade because of their indispensable role in soft materials. However, pure organic supramolecular polymers with stable room temperature phosphorescence (RTP) emission were very rarely reported for the difficulties of synthesis and achieving RTP in solution. Herein, soluble helical supramolecular polymers with circularly polarized room-temperature phosphorescence were developed via a facile host-guest strategy. Through assembly, a transition from pure fluorescence to almost pure RTP emission was achieved. Adjusting the asymmetry of guest could easily control the chiroptical property of supramolecular polymers. This work provides new opportunities for the design and development of intelligent soft functional soft materials. [ABSTRACT FROM AUTHOR]

N‐Heterocyclic carbene adducts with main group elements (NHC=E) have aroused great interest and have been widely investigated in coordination chemistry. Among them, N‐heterocyclic carbene adducts with chalcogens (NHC=Ch) have been known for a long time. Their investigations mostly focused on synthesis, coordination chemistry and electrochemistry. Their photophysical properties still remain unexplored. In this work, the photophysical properties of mesoionic carbene adducts with sulfur and selenium have been investigated both in solution and solid state. These compounds showed blue fluorescence in dichloromethane. While in solid state, orange to red room‐temperature phosphorescence can be observed, and dual emission was found in mesoionic thiones. Furthermore, time‐dependent density functional theory (TD‐DFT) calculations were used to obtain insights into the luminescent mechanism. [ABSTRACT FROM AUTHOR]

A QTAIM and IQA investigation on model compounds of two isostructural AgI and CuI coordination polymers (CPs) based on cyclic triimidazole (L), i.e. the [MIL]n 1D double‐stranded stair chain and the [MClL]n 3D network (M = Cu, Ag), has allowed light to be shed on the different emissive behaviour associated with the two metal ions. According to a previously reported investigation [Malpicci et al. (2021). Inorg. Chem. Front.8, 1312–1323], AgI CPs showed both fluorescence and multiple ligand‐centred room‐temperature phosphorescences, whereas CuI CPs displayed non‐thermally equilibrated halogen and metal‐to‐ligand charge transfer and two ligand‐centred phosphorescences, the latter observed only by their selective activation. Analysis of both local and integral QTAIM descriptors, including delocalization indices and source function, of the Ag—N and Cu—N bonds reveals a higher covalent and local character for the latter, explaining the greater metal–ligand electronic communication observed for the Cu compounds. Moreover, IQA investigation shows that the Cu—N bond is characterized by higher interaction energy, due to both higher electrostatic and exchange‐correlation contributions. Analysis on the M—X (M = Ag, Cu; X = I, Cl) bonds, also present in these structures, highlights a much higher covalent and local character with respect to the M—N bonds. [ABSTRACT FROM AUTHOR]

Organic room‐temperature phosphors with high performances are of great importance for broad range of potential applications. Herein, a new concept of cage effect is proposed to effectively promote room‐temperature phosphorescence (RTP) property of organic materials. A novel phosphor, bearing electron‐donating carbazole and electron‐accepting boronate ester moieties (CBBU) is designed and synthesized. CBBU crystals show multiple photoluminescence including concomitant fluorescence, thermally activated delayed fluorescence (TADF), and RTP. Further doping CBBU in boronate ester crystals (DB/CBBU) boosts remarkably deep‐blue RTP emission with CIE coordinates (0.15, 0.09) and a lifetime of 3.69 s, which is longer by four orders of magnitude than that of neat CBBU crystals. To the best of knowledge, it is the longest deep‐blue organic RTP materials reported so far. To understand this phenomenon, cage effect in terms of bending, twisting, and crowding degrees, as well as interaction of chromophores with cages has been taken into consideration. The results demonstrate that the strong cage effect alleviates effectively molecular motion of chromophores and then promotes simultaneously their RTP efficiency and lifetime. Similar results have also been found in a series of boronate ester derivatives. Furthermore, applications of the efficient RTP materials for temperature measurements, thermal transition detection, and UV sensing are exploited. [ABSTRACT FROM AUTHOR]

At room temperature (RT), the weak and strong cluster‐centered luminescence of silver and copper iodide clusters, respectively, has been widely reported. Though the central metal ions show same d10 electrons and similar coordination mode, the mechanism of their distinct emission properties is still unclear, which restricts further applications. In this work, it is found that different photoluminescence quantum yields (PLQYs) are caused by various collision energy transfers between the metal ions in clusters, like a kind of aggregation‐caused quenching mechanism. Concretely, isostructural coordination polymers (CPs) of Ag(I) and Cu(I) iodide clusters are synthesized. The Ag(I)‐CP shows no luminescence at RT while the PLQY of Cu(I)‐CP boosts to 89%, in which short radius and weak collision between metal ions are found. Moreover, shorter Cu(I)‐Cu(I) and longer Ag(I)‐Ag(I) distances are realized in the similar structure and they display prospective luminescence, which proves the collisional quenching mechanism. Inspired of the above, the heterometallic materials with high sensitivities and wide sensing windows to temperature detection are obtained through tuning the metal content, and they are also fabricated into detecting sequences, which satisfies the wide‐range temperature sensing. This work proposes an efficient strategy to improve RT photoluminescence and broaden temperature sensing windows. [ABSTRACT FROM AUTHOR]

Room‐temperature phosphorescent (RTP) nitrogen‐doped carbon dots (N‐CDs) have attracted great interest but their efficiency is usually dependent on a solid matrix. Developing efficient matrix‐free RTP CDs is still a great challenge. Here, a simple strategy is reported to synthesize efficient matrix free RTP N‐CDs from citric acid (CA) and basic fuchsine (BF) via a single step hydrothermal process. The synthesized N‐CDs show strong fluorescence in aqueous solution and the solid state, and the RTP lifetime is long‐lived (51.9 ms at 298 K). The phosphorescence of the N‐CDs is attributed to the formation of an internal hydrogen bonded network by the organic polymers on the surface of the N‐CDs. This reduces the nonradiative transitions of the triplet excitons and mitigates oxygen quenching. The application of N‐CDs as security inks is demonstrated. [ABSTRACT FROM AUTHOR]

Pure organic room‐temperature phosphorescence (RTP) materials have attracted wide attention for their easy preparation, low toxicity, and applications in various fields like bioimaging and anti‐counterfeiting. Developing phosphorescent systems with more universality and less difficulty in synthesis has long been the pursuit of materials scientists. By employing a polymeric quaternary ammonium salt with an ionic bonding matrix and heavy atoms, commercial fluorescent dyes are directly endowed with phosphorescence emission. In a single amorphous polymer, the external heavy‐atom effect generates excited triplet states and the rigid polymer matrix stabilizes them. This study put forward a new general strategy to design and develop pure organic RTP materials starting from existing library of organic dyes without complicated chemical synthesis. [ABSTRACT FROM AUTHOR]

The spin-forbidden nature of triplet exciton transitions is a limitation for achieving a carbon dots-based material with room-temperature phosphorescence (RTP). Here, fluorine-nitrogen co-doped carbon dots (FNCDs), prepared using the solvothermal method and further gas-phase fluorination from fructose and diethylenetriamine (DETA), were found to exhibit RTP lifetime and quantum yield of 1.14 s and 8.3%. By comparing the structure and performance of the nitrogen-doped carbon dots (NCDs) and FNCDs, it was found that the RTP of FNCDs originates from the π→π∗ and n→π∗ electron transitions C–N/C N, which can be attributed to the small energy gap between the singlet and triplet states. We further explored the mechanism of RTP by analyzing the hydrogen bonding between carbon dots and polyvinyl alcohol matrix. The semi-ionic C–F bonds also enhance intramolecular and intermolecular hydrogen bonding and reduce the quenching of RTP without the oxygen barrier. Furthermore, we applied the prepared aqueous FNCDs as an advanced security ink for information printing and anti-counterfeiting. The effective conversion of fluorescence to room temperature phosphorescent carbon dots is achieved by fluorinating NCDs to enhance intersystem crossing and stabilize the triplet-excited states. The NCD and FNCD aqueous solutions made into advanced anti-counterfeiting inks have the prospect of being used in information printing and anti-counterfeiting. [Display omitted] [ABSTRACT FROM AUTHOR]

It is an accepted approach to construct room‐temperature phosphorescence (RTP) materials by suppressing the non‐radiative decay process. However, there is limited success in developing fluid phosphorescence materials owing to the ultrafast non‐radiation relaxation of vibration and collision of molecules in fluid matrixes. Here, a universal deep‐eutectic‐solvent strategy is proposed for developing pure organic phosphorescent fluid materials that are able to generate effective phosphorescent emissions at both room temperature (ΦRTP,293 K≈30 %) and even higher temperature (ΦRTP,358 K≈4.53 %). Based on these findings, a qualitative analytical method was developed for leak detection and a quantitative analytical technique was further validated to help visually identify the heat distribution of irregular surfaces. This advancement empowers the current organic phosphorescent system offering an alternative to determine moisture and heat from non‐invasive photoluminescence emission colors. [ABSTRACT FROM AUTHOR]

Control of excited‐state dynamics is key in tuning room‐temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) emissions but is challenging for organic luminescent materials (OLMs). We show the regulation of TADF and RTP emissions of a boron difluoride β‐acetylnaphthalene chelate (βCBF2) by controlling the excited‐state dynamics via its J‐ and H‐aggregation states. Two crystalline polymorphs emitting green and red light have been controllably obtained. Although both monoclinic, the green and red crystals are dominated by J‐ and H‐aggregation, respectively, owing to different molecular packing arrangements. J‐aggregation significantly reduces the energy gap between the lowest singlet and triplet excited states for ultra‐fast reverse intersystem crossing (RISC) and enhances the radiative singlet decay, together leading to TADF. The H‐aggregation accelerates the ISC and suppresses the radiative singlet decay, helping to stabilize the triplet exciton for RTP. [ABSTRACT FROM AUTHOR]

Organic phosphors exhibiting room‐temperature phosphorescence (RTP) in amorphous phase are good candidates for optoelectronic and biomedical applications. In this proof‐of‐concept work, a rational strategy to activate wide‐color ranged and persistent RTP from amorphous films by embedding electron‐rich organic phosphor into electron‐deficient matrix polyacrylonitrile (PAN) is presented. Through tailoring noncovalent interactions between the electron‐deficient PAN matrix and electron‐rich organic phosphors, an ultralong lifetime of 968.1 ms is obtained for doped film TBB‐6OMe@PAN. Control experiments conducted on the polymers polymethyl methacrylate (PMMA) and polystyrene (PS) without electron‐withdrawing groups, and organic phosphors containing electron‐withdrawing groups indicate that the persistent RTP of doped films may be triggered by strong electrostatic interactions between electron‐deficient PAN and electron‐rich organic phosphor. Further theoretical calculations including electrostatic potential distributions, binding energies, and energy decomposing analysis demonstrate that both electrostatic and dispersion interactions between electron‐deficient PAN and electron‐rich organic phosphor are responsible for the activation of persistent RTP of doped films. In addition, the doped film TBB‐6OMe@PAN still maintains brightness even after soaking in water for 12 weeks. This excellent water resistance not only is favorable for future applications but also demonstrates an advantage of electrostatic and dispersion interactions over hydrogen bonding interactions. [ABSTRACT FROM AUTHOR]

Pure organic room-temperature phosphorescent (RTP) materials have been attracting widespread attention due to the unique properties and broad applications. However, RTP materials with the adjustable photochromic property are still a challenge. Based on this, two polymers containing hexaarylbiimidazole are strategically designed with dual emission of both fluorescence and phosphorescence. Furthermore, both polymers show sensitive photochromic responses from faint yellow to brown upon exposure to ultraviolet light. This study can enrich pure organic luminescent systems and provide new ideas for functional RTP materials. [ABSTRACT FROM AUTHOR]

The 24-membered ring - SYT type extra-large pore zeolite, denoted as DESO-SYSU-3, has been synthesized by employing N,N′-diethylsophoridine and trimethylsulfanium in a mixed-template system, where the N,N′-diethylsophoridine and trimethylsulfanium played different roles in the crystallization process. A single usage of N,N′-diethylsophoridine led to the formation of an unknown phase (donated as SYSU-5). These results reveal that the utilization of alkaloid-derived organic structure-directing agents (OSDAs) is an efficient synthetic strategy to produce specific extra-large pore zeolites and related structures. Compared to the prototype SYSU-3, the addition of TMSF into the system not only improved the silicon content in the framework of DESO-SYSU-3 but also facilitated the generation of carbon dots (CDs) confined in extra-large pore structure. The structure and the proposed formation mechanism of CDs were investigated based on HRTEM, XPS, FI-IR, UV–Vis, Raman and photoluminescence spectrum. The CDs@zeolite composite exhibited intriguing optical properties of both fluorescence and room temperature phosphorescence, respectively. This work extends extra-large pore zeolite as the matrix for the development of CDs@zeolite composites with tunable optical properties. In this work, N, N′-diethylsophoridine and trimethylsulfonium were combined to form a mixed-template system in the synthesis of germanosilicate zeolite. The mixed-template system not only produced the extra-large pore zeolite DESO-SYSU-3 with increased framework silicon content, but also facilitated the generation of carbon dots (CDs), which were confined in the zeolitic matrix and formed the composite with fluorescence and room temperature phosphorescence. When N, N′-diethylsophoridine was used as the sole template, an unknown germanosilicate SYSU-5 was produced. The different roles of N, N′-diethylsophoridine and trimethylsulfonium in the synthesis process as well as the photoluminescence mechanism of CDs@composite were investigated. [Display omitted] • Organosulfonium trimethylsulfonium (TMSF) was combined with N,N′-diethylsophoridine (DESO) to form a mixed-template system. • In the mixed-template system, extra-large pore zeolite DESO-SYSU-3 with increased framework silicon content was produced. • Single usage of DESO gave rise to an unknown germanosilicate phase (donated as SYSU-5). • Carbon dots were formed and confined into the zeolitic matrix during the hydrothermal synthesis. • DESO-SYSU-3 exhibited impressive fluorescence and room-temperature phosphorescence properties. [ABSTRACT FROM AUTHOR]

[Display omitted] Due to the high temperature that can easily lead to non-radiative transitions of triplet excitons, obtaining high-temperature phosphorescence (HTP) materials is challenging. Herein, using diarylfuro[3,2- b ]pyridines as the guest molecules and polyacrylic acid (PAA) as the host molecule, the two-component doped materials exhibit green room-temperature phosphorescence (RTP) with afterglow times of 2–8 s, delayed lifetimes of 256–939 ms, and phosphorescence quantum efficiencies of 140.3–21.2 %, and green HTP emissions with 2 s afterglow and 208 ms delayed lifetime at 373 K. The HTP activity of the doped system originates from the rigid environment provided by PAA , planar and rigid molecular structures of diarylfuro[3,2- b ]pyridines, and strong interactions between PAA and diarylfuro[3,2- b ]pyridines. Furthermore, using organic small molecules as the reference host molecules, compared to benzophenone, 5-methylphthalic anhydride, and butane-1,2,3,4-tetracarboxylic acid with chemical structures similar to PAA result in better RTP/HTP properties, revealing that strong interactions between host and guest molecules play a very important role in ultralong phosphorescence emissions of these host–guest doped materials. Moreover, these doped materials based on diarylfuro[3,2- b ]pyridines can be developed as advanced anti-counterfeiting and encryption materials. This result provides valuable reference for developing excellent RTP/HTP materials based on N,O-containing fused-ring compounds. [ABSTRACT FROM AUTHOR]

Organic room-temperature phosphorescence (RTP) shows high potential in optical fields, and self-assembly method via various non-covalent interactions is one facile and efficient way to enhance RTP performance. Herein, we investigated the RTP behaviors of three imidazole-based polymer films containing imidazole, methyl imidazolium, and benzyl imidazolium moieties, respectively. Their RTP behaviors and chemical structures were compared and discussed to explore the underlying structure-properties relationships. Owing to plenty of hydrogen bonds of polyacrylamide matrix to lock phosphors, imidazolium-based films gave an obvious green RTP due to cations and iodine anions-enhanced intersystem crossing. The blue RTP signals of imidazole-containing film was aroused by coordination with Zn2+ ions due to crosslinking and heavy atom effects. Moreover, the RTP performance of benzyl imidazolium-based film was remarkably improved by host-guest complexation with cucurbit[7]uril, showing a long lifetime up to 230.6 ms. By utilizing the difference in their RTP lifetimes, information encryption application was successfully achieved as a proof of concept. [Display omitted] [ABSTRACT FROM AUTHOR]

Two binaphthyl-based hyperbranched polyarylenes were facilely synthesized by the p -TsOH·H 2 O-catalyzed polycyclotrimerization of trimethylsilyl-protected internal diynes. They exhibited electrochemical properties and optical activities. When doped into the PVA matrix, the polymers showed yellow room-temperature phosphorescence. [Display omitted] • Two binaphthyl-based hyperbranched polyarylenes were synthesized by organo-catalyzed alkyne polycyclotrimerization. • They show electrochemical properties and optical activities. • When doped into PVA matrix, they exhibit room-temperature phosphorescence properties. Binaphthyl-based polymers have attracted increasing interest due to their unique properties and wide applications. Nevertheless, binaphthyl-containing hyperbranched polymers are rarely reported. Herein, two binaphthyl-based hyperbranched polyarylenes with high molecular weights were facilely synthesized in satisfactory yields by the polycyclotrimerization of internal diynes containing binaphthyl units in 1,2,4-trichlorobenzene (TCB) under heating in the presence of p -toluenesulfonic acid monohydrate (p -TsOH·H 2 O). The resultant polymers are soluble in common organic solvents, and thermally stable with 5% weight loss temperatures higher than 380 °C. They showed electrochemical properties, and optical activities. Furthermore, the polymer-doped polyvinyl alcohol (PVA) films exhibited yellow room-temperature phosphorescence (RTP) with the lifetime longer than 630 ms. [ABSTRACT FROM AUTHOR]

Room-temperature phosphorescent materials are widely concerned due to their potential applications in information encryption, anticounterfeiting and display. Herein, a rational strategy is designed by coassembling the carbazole derivatives with Laponite and poly (vinyl alcohol) (PVA) to inhibit their molecular rotation and vibrations. Laponite suppresses the nonradiative decay by abundant hydrogen bonds crosslinking with phosphorescent molecules and PVA chains. The synthesized inorganic-organic hybrid films are well used in information encryption and anticounterfeiting. Thus, this work provides a novel strategy for enhancing phosphorescence emission by doping organic molecules and Laponite in polymeric systems. The inorganic-organic hybrid film is prepared by supramolecular coassembly of carbazole derivatives and Laponite by solvent-free grinding, and then doped into PVA system, showing great potential in intelligent anticounterfeiting. [Display omitted] • Inorganic-organic hybrid film with enhanced phosphorescence lifetime and efficiency is synthesized. • Phosphorescence enhancement is owing to synergistic hydrogen bonding between Laponite and polymeric systems. • Intelligent anticounterfeiting is demonstrated by using this film. [ABSTRACT FROM AUTHOR]

The development of an accurate phosphorescent regulation strategy is key to customizing carbon dots (CDs) for anti-counterfeiting applications. To this target, we design a simple substrate regulation technique to manipulate phosphorescence of nitrogen-doped CDs (NCD). In this work, a cost-effective and environmentally friendly approach is proposed for combining NCD with urea (UA), boric acid (BA) and silica (SiO 2) through hydrogen bonding or covalent bonding, a series of RTP composites were designed and synthesized. The RTP wavelength and lifetime of the composites can be tuned effectively, by preparing composite materials (NCD/UA , NCD/BA and NCD/SiO 2) composed of NCD and different substrate (UA; BA; SiO 2). The average RTP lifetime of NCD/UA , NCD/BA and NCD/SiO 2 are 332.26 ms, 652.05 ms and 1587.22 ms, respectively. Furthermore, the RTP mechanism is verified. This facilitates the application of RTP materials and the adjustment of properties to practical requirements. Owing to the different phosphorescent wavelength and lifetime of NCD/UA , NCD/BA and NCD/SiO 2 , time-dependent multiple anti-counterfeiting can be achieved. Cell experiments show that NCD , NCD/BA , NCD/UA and NCD/SiO 2 have low cytotoxicity and good biocompatibility. This result indicates these RTP materials can be potentially used to realize multicolor and time-dependent anti-counterfeiting. [Display omitted] • The RTP lifetimes and colors tuning of NCD are realized by substrates regulation. • The photophysical properties and RTP mechanism were investigated systematically. • The average lifetimes of these materials were calculated to be 0.3–1.5 s. • These materials can realize multicolor and time-dependent anti-counterfeiting. [ABSTRACT FROM AUTHOR]

In recent years, oxidized phenothiazine derivatives with low toxicity, environmentally friendly behavior and great photophysical properties have become a research hotspot in room-temperature phosphorescence (RTP) materials. Researchers usually regulate packing modes by introducing different functional groups to obtain different RTP properties. This work focuses on the effect of relative packing mode characterized by overlapping area, vertical distance and slip angle on RTP performance by exploring the electron transition processes of the dimers. The results suggest that 5,5-dioxide phenothiazine derivatives would generate RTP phenomenon when the overlapping area is within 25–60 %, the vertical distance is within 2.1–3.0 Å and the slip angle is within 54–90° after we scanned intermolecular relative positions of the parent skeleton dimers with π–π stacking. In the range of above packing modes, the excitons prefer jumping to high excited singlet states which could generate more triplet excitons through the ISC process, reducing nonradiative transition rate, and transition back to the ground state in the form of RTP radiation, which is verified by some reported experimental oxidized phenothiazine derivatives when we carried out similar calculations on them. This focuses on the overlapping area, vertical distance and slip angle in 5,5-dioxide phenothiazine derivatives could provide interesting findings for the RTP materials. • The correlation between the packing methods and RTP phenomenon in derivative crystals. • Packing methods: overlapping area, vertical distance, slip angle. • RTP phenomenon would be generated in the range of 25-60% overlapping area, 2.1-3.0 Å vertical distance, 54-90° slip angle. • More triplet excitions are gengerated by ISC and prefer transitioning to S 0 in the form of radiation. k nr would be reduced. [ABSTRACT FROM AUTHOR]

Understanding the local triplet (3LE), charge transfer triplet (3CT), and charge transfer singlet (1CT) is of great importance in designing thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP) materials for their use in organic light‐emitting devices (OLEDs), sensing, and bioimaging. Herein, two phenothiazine–quinoline conjugates (PTzQ1, PTzQ2) in which the donor (PTz) and acceptor (Q1, Q2) parts are held in near‐orthogonal orientation that gives rise to spatial separation of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are reported. Photophysical studies of both conjugates along with their individual components (PTz, Q1, Q2) show that TADF occurs via reverse intersystem crossing (rISC) from the upper‐level local triplet (3LE) to lower‐level singlet 1CT mediated by vibronic coupling between 3LE and 3CT, whereas RTP is realized from 3LE. It is found that all three excited states are close in energy, 0.16–0.19 eV (3LE−1CT), 0.02–0.03 eV (1CT−3CT), and 0.14–0.16 eV (3LE−3CT) with the order of 3LE > 1CT > 3CT. Both conjugates exhibit a high rate constant of rISC (krISC, 7.9–9.7 × 105 s−1), resulting in external quantum efficiency (EQE) values of ≈4.7% (solution processed) with emission from both RTP and TADF components.

Manipulation of long‐lived triplet excitons in organic molecules is key to applications including next‐generation optoelectronics, background‐free bioimaging, information encryption, and photodynamic therapy. However, for organic room‐temperature phosphorescence (RTP), which stems from triplet excitons, it is still difficult to simultaneously achieve efficiency and lifetime enhancement on account of weak spin–orbit coupling and rapid nonradiative transitions, especially in the red and near‐infrared region. Herein, we report that a series of fluorescent naphthalimides—which did not originally show observable phosphorescence in solution, as aggregates, in polymer films, or in any other tested host material, including heavy‐atom matrices at cryogenic temperatures—can now efficiently produce ultralong RTP (ϕ=0.17, τ=243 ms) in phthalimide hosts. Notably, red RTP (λRTP=628 nm) is realized at a molar ratio of less than 10 parts per billion, demonstrating an unprecedentedly low guest‐to‐host ratio where efficient RTP can take place in molecular solids. [ABSTRACT FROM AUTHOR]

Fluorescence and phosphorescence are known as two kinds of fundamental optical signals, which have been used for myriad applications. To date, simultaneous activation of stable fluorescence and long‐lived room‐temperature phosphorescence (RTP) emission in the aqueous phase remains a big challenge. We prepare zinc‐doped silica nanospheres (Zn@SiNSs) with fluorescence and RTP properties using a facile hydrothermal synthetic strategy. For the as‐prepared Zn@SiNSs, the recombination of electrons and holes in defects and defect‐stabilized excitons derived from oxygen vacancy/C=N bonds lead to the production of stable fluorescence and long‐lived RTP (emission lasting for ≈9 s, quantum yield (QY): ≈33.6 %, RTP lifetime: ≈236 ms). The internal Si−O bonded networks and hydrophilic surface in Zn@SiNSs can reduce nonradiative decay to form self‐protective RTP, and also provide high water solubility, excellent pH‐ and photostability. [ABSTRACT FROM AUTHOR]

Angular sulfide and sulfone bridged cis-benzothiazinophenothiazine derivatives with phenyl and benzoyl attached at the amino positions were synthesized and characterized. Crystallographic analyses revealed their twisted structures. The phenyl substituted sulfone bridged benzothiazinophenothiazine demonstrated bright fluorescence emission in both solution and crystalline state. The benzoyl substituted benzothiazinophenothiazine and the sulfone derivatives showed room-temperature phosphorescence in the crystalline states. The electron-rich phenyl substituted cis-benzothiazinophenothiazine compound could be chemically oxidized to monocation and dication with gradually planarized structures depending on the oxidation states. [ABSTRACT FROM AUTHOR]

Room-temperature phosphorescence (RTP) of arenes, naphthalene-d8 and phenanthrene, in complexes with β-cyclodextrin (βCD) in the presence of a third component, tert-butylbenzene or p-tert-butyltoluene, providing the appearance of long-lived arene RTP, has been studied. The RTP lifetimes τph of naphthalene-d8 in the naphthalene-d8–βCD–tert-butylbenzene and naphthalene-d8–βCD–p-tert-butyltoluene complexes in the presence of oxygen are 14 and 4.8 s, respectively, and increase up to 16.4 and 6.6 s after oxygen removal. The rate constants of the phosphorescence quenching in these complexes are 34.4 and 76 L mol−1 s−1, respectively, indicating a high degree of naphthalene-d8 isolation from oxygen in the supramolecular system based on βCD. The highest value of τph for phenanthrene in the phenanthrene–βCD–tert-butylbenzene complex in the presence of oxygen is 2.4 s. The RTP decay in the presence of oxygen is always the superposition of two exponents, which is the general property of such three-component complexes, and indicates the presence of two types of phosphorescing complexes. The proposed structures of the complexes have been calculated by the quantum-chemistry method. The mechanism of the arene RTP quenching by oxygen is discussed with the use of the calculated structures of the complexes. [ABSTRACT FROM AUTHOR]

Ultralong organic room-temperature phosphorescence (RTP) materials have attracted tremendous attention recently due to their diverse applications. Several ultralong organic RTP materials mimicking the host-guest architecture of inorganic systems have been exploited successfully. However, complicated synthesis and high expenditure are still inevitable in these studies. Herein, we develop a series of novel host-guest organic phosphorescence systems, in which all luminophores are electron-rich, commercially available and halogen-atom-free. The maximum phosphorescence efficiency and the longest lifetime could reach 23.6% and 362 ms, respectively. Experimental results and theoretical calculation indicate that the host molecules not only play a vital role in providing a rigid environment to suppress non-radiative decay of the guest, but also show a synergistic effect to the guest through Förster resonance energy transfer (FRET). The commercial availability, facile preparation and unique properties also make these new host-guest materials an excellent candidate for the anti-counterfeiting application. This work will inspire researchers to develop new RTP systems with different wavelengths from commercially available luminophores. [ABSTRACT FROM AUTHOR]

Purely organic circularly polarized luminescent (CPL) materials have attracted much attention owing to their fascinating photophysical properties and potential applications in the fields of optical data storage, smart sensors/probers, high‐resolution 3D display, and so on. With the development of photophysical science, the emergence of some novel emission phenomena, such as thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP), have become hot topics and enriched CPL materials. However, there is no systematic review that summarizes the recent development of chiral small organic molecules (SOMs) with TADF and RTP characters. In this minireview, the progress of purely organic CPL materials in the last 5 years is reviewed by categorizing into chiral fluorescence molecules, chiral TADF molecules, and chiral RTP molecules. Furthermore, the design strategy of chiral TADF emitters is discussed and the correlation between chirality and RTP properties is concluded.

Recently, a remarkable advance has been made for metal‐free room‐temperature phosphorescence (RTP) crystals with high phosphorescence quantum yield. However, amorphous, especially heavy‐atom‐free, RTP materials still suffer from low quantum yield due to the transition‐forbidden character of phosphorescence and the relatively poor suppression of nonradiative transition in amorphous materials. In this study, a series of single‐benzene structure‐based high intersystem crossing yield phosphor is obtained. After embedding into polyvinyl alcohol matrix, all these phosphor exhibits efficient phosphorescence emission (ФP, up to 44.0%). Besides, photo‐switchable phosphorescence emission can be obtained by doping these molecules into a polymethyl methacrylate (PMMA) matrix. The phosphorescence can be gradually switched on by consuming the residual oxygen in the PMMA matrix under continuous UV light irradiation. Furthermore, the phosphorescence will be spontaneously switched off under ambient conditions. Taking advantage of the photoactivation character, this material has potential in information storage and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Development of pure organic room‐temperature phosphorescent (RTP) materials with strong emission and decent processability is highly desirable. However, in the pursuit of high quantum yield (QY) of phosphorescence, the processability of RTP materials is suppressed unwarily. Here, a liquid crystalline (LC) copolymer is envisioned, NpA‐Chol, comprising bromonaphthalimide as the phosphor and cholesterol as the LC mesogen. NpA‐Chol exhibits LC flexibility at high temperatures, thus enabling the material to possess decent processability. In addition, the liquid crystallinity of NpA‐Chol could be improved remarkably after thermal annealing, making a 7.5‐fold increase in phosphorescence QY. This cholesterol copolymerization strategy paves a general avenue for addressing the major defect well: highly efficient RTP materials always suffer from suppression of thermal processability. [ABSTRACT FROM AUTHOR]

Sulfur dots are a new class of recently developed nonmetallic luminescent nanomaterials with various potential applications. Herein, we synthesized sulfur dots using a mild chemical etching method and then modified the structural features of the as-synthesized sulfur dots using a slow and defined solvent-assisted aggregation process. This increases the particle size and overall crystallinity along with the modifications of the surface functional groups, which eventually show a new emission band at longer wavelengths. Detailed photophysical and temperature-dependent luminescence studies confirmed that the new emissive state evolves due to interparticle interactions in the excited state. Furthermore, the occurrence of a new emissive state in a longer-wavelength region helped reduce the energy gap between the lowest excited singlet state and the lowest excited triplet state in modified sulfur dots, resulting in an aqueous stable room-temperature phosphorescence/afterglow emission through efficient intersystem crossing. This typical efficacious afterglow emission directly shows the potential applicability of structurally modified sulfur dots in encryption devices and can also be potentially effective in light emitting diodes (LED) and sensing devices.

Herein, a type of light- and heat-driven flexible supramolecular polymer with reversibly long-lived phosphorescence and photochromism is constructed from acrylamide copolymers with 4-phenylpyridinium derivatives containing a cyano group (P-CN, P-oM, P-mM), sulfobutylether-β-cyclodextrin (SBCD), and polyvinyl alcohol (PVA). Compared to their parent solid polymers, these flexible supramolecules based on the non-covalent cross-linking of copolymers, SBCD, and PVA efficiently boost the phosphorescence lifetimes (723.0 ms for P-CN, 623.0 ms for P-oM, 945.8 ms for P-mM) through electrostatic interaction and hydrogen bonds. The phosphorescence intensity/lifetime, showing excellent responsiveness to light and heat, sharply decreased after irradiation with a 275 nm flashlight or sunlight and gradually recovered through heating. This is accompanied by the occurrence and fading of visible photochromism, manifesting as dark green for P-CN and pink for P-oM and P-mM. These reversible photochromism and phosphorescence behaviors are mainly attributed to the generation and disappearance of organic radicals in the 4-phenylpyridinium derivatives with a cyano group, which can guide tunable luminescence and photochromism., (© 2024 Wiley‐VCH GmbH.)

Organic semiconductors provide the potential of biodegradable technologies, but prototypes do only rarely exist. Transparent, ultrathin programmable luminescent tags (PLTs) are presented for minimalistic yet efficient information storage that are fully made from biodegradable or at least industrially compostable, ready-to-use materials (bioPLTs). As natural emitters, the quinoline alkaloids show sufficient room temperature phosphorescence when being embedded in polymer matrices with cinchonine exhibiting superior performance. Polylactic acid provides a solution for both the matrix material and the flexible substrate. Room temperature phosphorescence can be locally controlled by the oxygen concentration in the film by using Exceval as additional oxygen blocking layers. These bioPLTs exhibit all function-defining characteristics also found in their regular nonenvironmentally degradable analogs and, additionally, provide a simplified, high-contrast readout under continuous-wave illumination as a consequence of the unique luminescence properties of the natural emitter cinchonine. Limitations for flexible devices arise from limited thermal stability of the polylactic acid foil used as substrate allowing only for one writing cycle and preventing an annealing step during fabrication. Few-cycle reprogramming is possible when using the architecture of the bioPLTs on regular quartz substrates. This work realizes the versatile platform of PLTs with less harmful materials offering more sustainable use in future., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)

Tunable-lifetime room-temperature phosphorescence (RTP) materials have been widely studied due to their broad applications. However, only few reports have achieved wide-range lifetime modulation. In this work, ultra-wide range tunable-lifetime efficient dark blue RTP materials were realized by doping methyl benzoate derivatives into polyvinyl alcohol (PVA) matrix. The phosphorescence lifetimes of the doped films can be increased from 32.8 ms to 1925.8 ms. Such wide range of phosphorescence lifetime modulation is extremely rare in current reports. Moreover, the phosphorescence emission of the methyl 4-hydroxybenzoate-doped film is located in the dark blue region and the phosphorescence quantum yield reaches as high as 15.4 %, which broadens their applications in organic optoelectronic information. Further studies demonstrated that the reason for the tunable lifetime was that the magnitude of the electron-donating ability of the substituent group modulates the HOMO-LUMO and singlet-triplet energy gap of methyl benzoate derivatives, as well as the ability to non-covalent interactions with PVA. Moreover, the potential applications of luminescent displays and optical anti-counterfeiting of these high-performance dark blue RTP materials have been conducted., (© 2024 Wiley-VCH GmbH.)

Molecular ultralong room-temperature phosphorescence (RTP), exhibiting multiple stimuli-responsive characteristics, has garnered considerable attention due to its potential applications in light-emitting devices, sensors, and information safety. This work proposes the utilization of photochemical cascade processes (PCCPs) in molecular crystals to design a stepwise smart RTP switch. By harnessing the sequential dynamics of photo-burst movement (induced by [2+2] photocycloaddition) and photochromism (induced by photogenerated radicals) in a bismuth (Bi)-based metal-organic halide (MOH), a continuous and photo-responsive ultralong RTP can be achieved. Furthermore, utilizing the same Bi-based MOH, diverse application demonstrations, such as multi-mode anti-counterfeiting and information encryption, can be easily implemented. This work thus not only serves as a proof-of-concept for the development of solid-state PCCPs that integrate photosalient effect and photochromism with light-chemical-mechanical energy conversion, but also lays the groundwork for designing new Bi-based MOHs with dynamically responsive ultralong RTP., (© 2024 Wiley-VCH GmbH.)

Narrowband afterglow materials display interesting functions in high-quality anti-counterfeiting and multiplexed bioimaging. However, there is still a limited exploration of these afterglow materials, especially for those with a full width at half maxima (FWHM) around 30 nm. Here, we report the fabrication of narrowband organic/inorganic hybrid afterglow materials via energy transfer technology. Coronene (Cor) with a long phosphorescence feature and broad phosphorescence band is selected as the donor for energy transfer, and inorganic quantum dots (QDs) of CdSe/ZnS with a narrowband emission are used as acceptors. Upon doping into the organic matrix, the resultant three-component materials exhibit a narrowband afterglow with an afterglow lifetime of approximately 3.4 s and an FWHM of 31 nm. The afterglow wavelength of the afterglow materials can be controlled by the QDs. This work based on organic/inorganic hybrids provides a facile approach for developing multicolor and narrowband afterglow materials, as well as opens a new way for expanding the features of organic afterglow for multifunctional applications. It is expected to rely on narrowband afterglow emitters to solve the "spectrum congestion" problem of high-density information storage in optical anti-counterfeiting and information encryption.

It is of practical significance to develop polymer-based room-temperature phosphorescence (RTP) materials with ultralong lifetime and multicolor afterglow. Herein, the benzocarbazole derivatives were selected and combined with a poly(vinyl alcohol) (PVA) matrix by a coassembly strategy. Owing to the hydrogen-bonding interactions between benzocarbazole derivatives and the PVA matrix, the nonradiative transition and the quenching of triplet excitons are effectively inhibited. Therefore, the maximum phosphorescence emission lifetime of 2202.17 ms from ABfCz-PVA and the maximum phosphorescence quantum efficiency of 34.97% from ABtCz-PVA were obtained, respectively. In addition, commercially available dye molecules were selected to construct phosphorescent resonance energy transfer (PRET) systems for energy acceptors, enabling full-color afterglow emission in blue, green, yellow, red, and even white. Based on the characteristics of prepared RTP materials, multifunctional applications to flexibility, information encryption, and erasable drawing were deeply explored.

Recently, biomass-derived carbon dots (CDs) have attracted considerable attention in high-technology fields due to their prominent merits, including brilliant luminescence, superior biocompatibility, and low toxicity. However, most of the biomass-derived CDs only show bright fluorescence in diluted solution because of aggregation-induced quenching effect, hence cannot exhibit solid-state long-lived room-temperature phosphorescence (RTP) in ambient conditions. Herein, matrix-free solid-state RTP with an average lifetime of 0.50 s is realized in the CDs synthesized by one-pot hydrothermal treatment of duck feather waste powder. To further enhance RTP lifetime, hydrogen bonding is introduced by employing polyols like polyvinyl alcohol (PVA) and phytic acid (PA), and a bimodal luminescent CDs/PVA/PA ink is exploited by mixing the CDs and polyols. Astonishingly, the CDs/PVA/PA ink screen-printed onto cellulosic substrates exhibits unprecedented green RTP with average lifetime of up to 1.97 s, and the afterglow lasts for more than 14 s after removing UV lamp. Such improvement on RTP is proposed to the populated excited triplet excitons stabilized by rigid chains. Furthermore, the CDs/PVA/PA ink demonstrates excellent potential in anticounterfeiting and information encryption. To the best of the authors' knowledge, this work is the first successful attempt to fabricate matrix-free ultra-long RTP CDs by reclamation of the feather wastes for environmental sustainability., Competing Interests: The authors declare no conflicts of interest., (© 2024 The Author(s). Exploration published by Henan University and John Wiley & Sons Australia, Ltd.)

Molecules with nonplanar architectures are highly desirable due to their unique topological structures and functions. We report here the synthesis of two molecular containers (1 ⋅ 3Br - and 1 ⋅ 3Cl - ), which utilize intramolecular cation-π interactions to enforce macrocylic arrangements and exhibit high binding affinity and luminescent properties. Remarkably, the geometry of the cation-π interaction can be flexibly tailored to achieve a precise ring arrangement, irrespective of the angle of the noncovalent bonds. Additionally, the C-H⋅⋅⋅Br - hydrogen bonds within the container are also conducive to stabilizing the bowl-shaped conformation. These bowl-shaped conformations were confirmed both in solution through NMR spectroscopy and in the solid state by X-ray studies. 1 ⋅ 3Br - shows high binding affinity and selectivity: F - >Cl - , through C-H⋅⋅⋅X - (X=F, Cl) hydrogen bonds. Additionally, these containers exhibited blue fluorescence in solution and yellow room-temperature phosphorescence (RTP) in the solid state. Our findings illustrate the utility of cation-π interactions in designing functional molecules., (© 2024 Wiley-VCH GmbH.)