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0D Hybrid Zn/Cd Halied for Color-Time-Dual-Resolved Security Applications: We devise a family of zero-dimensional (0D) hybrid metal halides based RTP materials with dual phosphorescence performance and adjustable lifetime scale, which realize color-lifetime-dual-resolved encoding ability, showcasing potential applications in multilevel anti-counterfeiting and information security. [Display omitted] • A new optical multiplexing concept of simultaneously utilizing the varied emission color and lifetime as dual temporary codes was proposed. • A new family of zero-dimensional (0D) organic metal halides was directly synthesized accompanied by tailorable lifetime at the same molecular platform. • High-security anti-Counterfeiting and 4D information encryption-decryption were demonstrated. Luminescent materials with engineered optical properties play an important role in anti-counterfeiting and information security technology. However, conventional luminescent coding is limited by fluorescence color or intensity, and high-level multi-dimensional luminescent encryption technology remains a critically challenging goal in different scenarios. To improve the encoding capacity, we present an optical multiplexing concept by synchronously manipulating the emission color and decay lifetimes of room-temperature phosphorescence materials at molecular level. Herein, we devise a family of zero-dimensional (0D) hybrid metal halides by combining organic phosphonium cations and metal halide tetrahedral anions as independent luminescent centers, which display blue phosphorescence and green persistent afterglow with the highest quantum yields of 39.9 % and 57.3 %, respectively. Significantly, the luminescence lifetime can be fine-tuned in the range of 0.0968–0.5046 μs and 33.46–125.61 ms as temporary time coding through precisely controlling the heavy atomic effect and inter-molecular interactions. As a consequence, synchronous blue phosphorescence and green afterglow are integrated into one 0D halide platform with adjustable emission lifetime acting as color- and time-resolved dual RTP materials, which realize the multiple applications in high-level anti-counterfeiting and information storage. The color-lifetime-dual-resolved encoding ability greatly broadens the scope of luminescent halide materials for optical multiplexing applications. [ABSTRACT FROM AUTHOR]

The charge‐transfer (CT) complexes with significant electron delocalization demonstrate abundant appealing physicochemical features and unique orbital hybridization, creating great promise as artificial light‐harvesting antennas for advanced optoelectronics, such as high‐performance organic room‐temperature phosphorescence (RTP). Herein, originally, a localized CT complex is proposed in organic microcrystals for exceptional orange‐emissive RTP with photoluminescence peaks at 575 and 625 nm based on the light‐harvesting antennas of CT states in organic microcrystals with donor doping. The localized CT state antennas can capture more singlet excitons, and transition them into triplet excitons, efficiently promoting intersystem crossing (ISC). Owing to the dense packing structure and strong CT interaction, the generation and stabilization of triplet excitons under ambient conditions are facilitated, imparting effective RTP with a lasting afterglow of up to 3 s. The controlled intensity ratio of fluorescence and phosphorescence is successfully achieved via finely adjusting the donor doping ratio, presenting a tunable CIE evolution from (0.42, 0.30) to (0.25, 0.12). The potential applications of these light‐harvesting microcrystals in information encryption and flexographic printing are illustrated. [ABSTRACT FROM AUTHOR]

Materials with room‐temperature phosphorescence (RTP) from deep red to near‐infrared (NIR) region exhibit great potential for emerging applications. However, such molecules typically require a low‐lying first triplet (T1) excited state, which may not be optimal for exciton stabilization, potentially compromising the phosphorescence lifetime. This study reports the design of four 9H‐carbazole (Cz) analogs with extended conjugation lengths used as dopants to achieve RTP emissions in deep red and NIR regions with lifetimes exceeding 700 ms. These findings reveal that substituting reactive hydrogen atoms in Cz analogs with methyl groups significantly enhances the photoluminescence quantum yield (PLQY) of these materials compared to their non‐methylated counterparts. Additionally, these doping systems can be activated by visible light, achieving persistent phosphorescence even under the excitation of 450 nm light. Theoretical calculations demonstrate the crucial roles of charge transfer state and the enhanced spin‐orbital coupling (SOC) matrix elements upon doping for achieving long‐lifetime phosphorescence beyond 600 nm. This research presents a strategy employing Cz‐based doping systems to facilitate RTP emissions extending from visible to deep red and NIR regions. [ABSTRACT FROM AUTHOR]

The maintenance of triplet excitons to produce room‐temperature phosphorescence while simultaneously improving the luminescence dissymmetry factor (glum) and photoluminescence quantum yield (PLQY) makes the preparation of circularly polarized room‐temperature phosphorescence (CP‐RTP) materials challenging. Herein, two chiral cocrystals are reported with CP‐RTP using S/R‐1‐(1‐Naphthyl)ethanol (S/R‐1‐nea) as the donor and 1,2,4,5‐Tetracyanobenzene (TCNB) as the acceptor. Simultaneous enhancement of glum and PLQY is accomplished, with the greatest phosphorescence in the PLQY of ≈31% and |glum| of 0.065, which is one of the highest |glum| in cocrystals. Doping two chiral cocrystals into the polyvinyl alcohol (PVA) matrix resulted in polymer films with circularly polarized long afterglow luminescence, indicating the potential for multilevel encryption applications. This study provides a novel approach to achieve the dual improvement of glum and phosphorescence PLQY, and broadens the application prospects of CP‐RTP materials. [ABSTRACT FROM AUTHOR]

Organic emitters that exhibit room‐temperature phosphorescence (RTP) in neat films have application potential for optoelectronic devices, bio‐imaging, and sensing. Due to molecular vibrations or rotations, the majority of triplet excitons recombine rapidly via non‐radiative processes in purely organic emitters, making it challenging to observe RTP in amorphous films. Here, a chemical strategy to enhance RTP in amorphous neat films is reported, by utilizing through‐space charge‐transfer (TSCT) effect induced by intramolecular steric hindrance. The donor and acceptor groups interact via spatial orbital overlaps, while molecular motions are suppressed simultaneously. As a result, triplets generated under photo‐excitation are stabilized in amorphous films, contributing to phosphorescence even at room temperature. The solvatochromic effect on the steady‐state and transient photoluminescence reveals the charge‐transfer feature of involved excited states, while the TSCT effect is further experimentally resolved by femtosecond transient absorption spectroscopy. The designed luminescent materials with pronounced TSCT effect show RTP in amorphous films, with lifetimes up to ≈40 ms, comparable to that in a rigid polymer host. Photoluminescence afterglow longer than 3 s is observed in neat films at room temperature. Therefore, it is demonstrated that utilizing intramolecular steric hindrance to stabilize long‐lived triplets leads to phosphorescence in amorphous films at room temperature. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Designing room‐temperature phosphorescent (RTP) hydrogels presents a unique challenge in comparison to RTP polymeric films and powders, due to the quenching of phosphorescence by water molecules within the hydrogel and their inherent softness. This study presents the first example of intrinsic RTP hydrogels without doping by luminophores or stiffening agents. The hydrogel is synthesized by copolymerizing acrylamide (Am) with N‐acryloyl‐aminoundecanoic acid (NAUA). The hydrophobic NAUA induces phase separation in the hydrogel network and the glass transition of the hydrophobic phase can stiffen the structure and constrain the mobility of water molecules and chain segments. Under such condition, the clustering of amide and carboxylic acid groups triggers the emission of RTP with a persistent afterglow exceeding 1.5 s, which is as good as the reported RTP hydrogels with dopants. When the hydrogel is heated above its glass transition temperature, its modulus drops quickly from 20.0 to 0.026 MPa within 2 s and RTP also diminishes. Taking advantage of the temperature‐switchable rigidity and RTP behavior, the hydrogels are endowed with functions such as shape memory, temperature‐sensing, and information concealment. [ABSTRACT FROM AUTHOR]

Aiming to design new efficient organic triplet emitters, here a new electron‐accepting moiety 11,13‐dihydro‐12H‐dibenzo[a,c]imidazo[4,5‐i]phenazin‐12‐one (BIPO) are reported. Three new BIPO derivatives containing long alkyl chains, namely DBIPO (acceptor only), DBIPOBr (acceptor containing bromine atoms), and DBIPOAc with acridan moieties in a donor‐acceptor‐donor configuration, are designed and investigated. Efficient room temperature phosphorescence (RTP) is detected for the three compounds, stemming from a high‐lying (anti‐Kasha type) triplet emission occurring in the acceptor moiety. Additionally, the tetrahydrofuran‐ and dichloromethane DBIPOAc solutions show (i) a dual‐band photoluminescence profile stemming from anti‐Kasha emissions from high‐lying charge‐transfer (1CT) and locally excited (1LE) states, and (ii) a thermally activated delayed fluorescence (TADF) from the same high‐lying 1CT state. Importantly, DBIPOAc doped in rigid nonpolar polymer Zeonex simultaneously exhibits both TADF and RTP, with the emission quantum yield reaching 69.6%. Due to these properties, the BIPO derivatives constitute promising candidates as multi‐functional new emitters for the preparation of active layers of electroluminescent devices and optical oxygen/pressure sensors. The reasons for these interesting properties are discussed in detail. [ABSTRACT FROM AUTHOR]

The development of persistent room‐temperature phosphorescent (pRTP) hydrogels is important for the practical applications of organic phosphors. Unfortunately, the phosphorescence emission of nontraditional luminogens (NTLs) can be strongly quenched by water in hydrogel networks. Herein, a series of pRTP organohydrogels based on NTLs are prepared by dissolving poly(vinyl alcohol) (PVA), biuret (BIU) and poly(maleic acid) (PMAc) (or other nonaromatic macromolecular acids) in a glycerol/water mixed solvent, followed by a simple freezing‐thawing treatment. Very impressively, the organohydrogel exhibits remarkable excitation‐dependent and metal cation‐responsive phosphorescence with a maximum lifetime up to 782.8 ms at ambient conditions. Moreover, the organohydrogels treated with metal cations also have excitation‐dependent phosphorescence. Multidimensional information encryption can be achieved by simply printing solutions of metal cations onto the gel surface and switching the irradiation lights, or using gel blocks prepared with different macromolecular acids. Structural characterizations, mechanical tests, and comparative studies prove that hydrogen bonding between BIU and macromolecular chains leads to rigidification of molecular conformations and the cooperative effect of the components leads to the pRTP of the organohydrogels. This work provides a reliable strategy for the preparation of nonaromatic phosphorescent hydrogels with long afterglows and greatly expands the practical applications of phosphorescent materials. [ABSTRACT FROM AUTHOR]

The large‐scale fabrication of long‐lived and sustainable room‐temperature phosphorescence (RTP) materials with color‐tunable afterglow is of considerable practical importance in diverse optoelectronic applications but remains challenging. Herein, based on a process for the mass production of cellulose acetoacetate filaments, large‐scale RTP filaments are synthesized by introducing amino‐bearing luminophores via a mild enamine reaction. Attributed to efficient intersystem crossing facilitated by acetoacetyl and benzoyloxy groups alongside a rigid environment provided by multiple hydrogen bonding, the resulting filaments exhibit impressive RTP with a lifetime of 772 ms and a phosphorescence quantum yield of 45.06%. Furthermore, the afterglow color of RTP filaments is rationally modulated from blue to greenish‐yellow to rosy‐red through triplet‐to‐singlet Förster resonance energy transfer. Meanwhile, the formation of diverse clusters with comparable but different lifetimes leads to interesting excitation‐dependent afterglows. This work not only provides an effective strategy to construct long‐lived, color‐tunable, sustainable afterglows but also establishes large‐scale and continuous preparation routes for functional cellulose filaments. [ABSTRACT FROM AUTHOR]

Some marine animals form long‐lived luminescence for predation, communication, camouflage, and anti‐predation. These marine animals demonstrate soft nature, sustainable glowing, and underwater emission, which are difficult to achieve in synthetic room temperature phosphorescence (RTP) materials. Inspired by these marine animals, here the study reports RTP hydrogels that show long‐lived phosphorescence (lifetime >500 ms and afterglow >10 s) in water. Exceptional underwater mechanical properties are simultaneously achieved, including tensile strength of 5.1 MPa, tensile strain of 452%, and toughness of 19.3 MJ m−3. The key to this achievement lies in the in situ phase separation microarchitecture formed between polyacrylamide (PAM) and its partial hydrolysates, which confines the motions of polymer chains and protects vulnerable triplet excitons from quenching of water. Such a strategy shows the merits of facile fabrication without laborious synthesis. In addition, these RTP hydrogels offer repeatable photoprinting and highly stability in water, providing a versatile platform for underwater applications of RTP materials, including information encryption and camouflage of marine animals. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Room‐temperature phosphorescence (RTP) materials have experienced rapid development due to their potential in organic light‐ emitting diode, information security, bioimaging, etc. However, the design of chiral organic phosphors with circularly polarized RTP (CPP) property remains a formidable challenge. Here, we introduce a chiral perturbation approach using a combination of chiral binaphthol and phenoselenazine derivative to achieve CPP. The photoactivated CPP in polystyrene (PS) film demonstrates a luminescence dissymmetry factor (glum), emission efficiency, and RTP lifetime up to 9.32 × 10–3, 27.0%, and 40.0 ms, respectively. The remarkable sensitivity of PS film to oxygen and temperature enables the adjustable emission colors, ranging from green to offwhite and blue under varying conditions. The doping systems, utilizing hosts of triphenylphosphine and 9‐phenylcarbazole, demonstrate an extended CPP lifetime of 85.9 ms and exhibit a persistent mechanoluminescence property with low pressure response threshold as low as 0.15 N. The information security provided by this CPP material was attained via the using of diverse emission colors and afterglow generated by distinct UV irradiation times and host materials. Alternately, it can also be achieved by observing different emission patterns using R‐ and L‐polarizer. The research has presented a reliable approach for producing CPP materials with high emission efficiency and glum. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Room‐temperature phosphorescence (RTP) materials have experienced rapid development due to their potential in organic light‐ emitting diode, information security, bioimaging, etc. However, the design of chiral organic phosphors with circularly polarized RTP (CPP) property remains a formidable challenge. Here, we introduce a chiral perturbation approach using a combination of chiral binaphthol and phenoselenazine derivative to achieve CPP. The photoactivated CPP in polystyrene (PS) film demonstrates a luminescence dissymmetry factor (glum), emission efficiency, and RTP lifetime up to 9.32 × 10–3, 27.0%, and 40.0 ms, respectively. The remarkable sensitivity of PS film to oxygen and temperature enables the adjustable emission colors, ranging from green to offwhite and blue under varying conditions. The doping systems, utilizing hosts of triphenylphosphine and 9‐phenylcarbazole, demonstrate an extended CPP lifetime of 85.9 ms and exhibit a persistent mechanoluminescence property with low pressure response threshold as low as 0.15 N. The information security provided by this CPP material was attained via the using of diverse emission colors and afterglow generated by distinct UV irradiation times and host materials. Alternately, it can also be achieved by observing different emission patterns using R‐ and L‐polarizer. The research has presented a reliable approach for producing CPP materials with high emission efficiency and glum. [ABSTRACT FROM AUTHOR]

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-tosinglet 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. [ABSTRACT FROM AUTHOR]

The efficient utilization of clean and safe sunlight as an excitation source for room‐temperature phosphorescent (RTP) materials is crucial for practical applications in solar energy. Herein, sunlight‐activated RTP nitrogen‐doped carbon dots @ alumina (N‐CDs@Al2O3) composites with long lifetime and exceptional stability are designed and fabricated using an in situ preparation strategy. The N‐CDs@Al2O3 display bright yellow RTP (more than 18 s to the naked eye) when activated by sunlight. The results indicate that the introduction of nitrogen into the CDs not only promotes the effective filling of triplet excitons but also facilitates the red‐shift of the absorption spectrum of the CDs. The high rigidity structure of Al2O3 and stable strong covalent bonds effectively protect the triplet excitons. Additionally, the numerous oxygen vacancy defects formed under appropriate calcination conditions effectively store and release triplet excitons. Finally, the application of N‐CDs@Al2O3 in multi‐color 3D artworks, defense markings, and emergency signs is demonstrated. This work provides design principles and feasible strategies for the development of new sunlight‐activated RTP materials. [ABSTRACT FROM AUTHOR]

Organic afterglow can be generated from persistent thermally activated delayed fluorescence (pTADF) or organic ultralong room temperature phosphorescence (OURTP), but the pTADF plus OURTP type organic afterglow is challenging to achieve, especially for the color‐tunable and high‐temperature ones. Herein, an accessible strategy toward such dual‐mode afterglow is presented by doping the indolo[3,2‐b]carbazole (ICZ‐p1) into polymethyl methacrylate (PMMA). The resulting films exhibit photo‐activated afterglow with two persistent emission peaks of ca. 435 and 497 nm. Impressively, their longest lifetimes respectively reach to 2.28 and 2.47 s at 298 K, along with 0.32 and 0.42 s at 360 K, enabling the afterglow at room and high temperature. Experimental and theoretical results reveal that the photo‐activated afterglow is associated with the elimination of molecular O2 inside film and composed by the pTADF with multi‐resonance (MR) effect and OURTP. By altering the temperature from 77 to 358 K, the color‐tunable afterglows of green and blue are harvested at such temperature ranges. Benefiting from the multi‐resonance thermally activated delayed fluorescence (MRTADF) characteristics, this emitter can release narrow‐band electroluminescence. Consequently, the results obtained here may offer important references for chasing MRTADF plus OURTP‐type dual‐mode organic afterglow showing color‐tunable and high‐temperature features. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Avoiding the tedious process of crystal cultivation and directly obtaining organic crystals with desirable phosphorescent performance is of great significance for studying their structure and properties. Herein, a set of benzophenone‐cored phosphors with bright green afterglow are obtained on a large scale through in‐situ generation via an end‐capping strategy to suppress non‐radiative triplet excitons and reinforce the intermolecular interactions. The ordered arrangement of phosphors with alkyl‐cyano groups as regulators is crucial for the enhancement of room‐temperature phosphorescence (RTP) emission, which has been further verified by the attenuated lifetimes in isolated states through the formation of inclusion complexes upon binding with pillar[5]arenes. Moreover, the hierarchical interactions of phosphors, including hydrogen bonding, π‐π stacking interactions, and van der Waals forces, are quantified by crystal structures and theoretical calculation to deeply interpret the origins of RTP emission. With this study, we provide a potential strategy for the direct acquisition of crystalline organic phosphors and modulation of RTP. [ABSTRACT FROM AUTHOR]

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

Herein, cucurbituril‐regulated supramolecular multi‐dimensional organic framework constructed is reported by tetraphenylvinyl grafted bromophenylpyridine salt derivatives (TPE‐BrN) and cucurbit[n]uril (n = 6, 7, 8) via non‐covalent cross‐linked, giving supramolecular macrocycle‐confined fluorescence‐phosphorescence dual emission at 560 and 510 nm in solid state. Different from the formation of TPE‐BrN⊂CB[6] complexes and TPE‐BrN⊂CB[7] nanoparticle, TPE‐BrN⊂CB[8] manifested high‐efficient 2D network assembly. TPE‐BrN⊂CB[8] assembly can effectively activate triplet‐state to singlet‐state Förster resonance energy transfer (TS‐FRET) with long‐lived near‐infrared emission at 675 nm via doping organic dye Nile red (NiR) and the energy transfer efficiency reached up to 99%. Although CB[7] can also induce the typical phosphorescence emission at 510 nm, there is no TS‐FRET occurring after doping NiR into TPE‐BrN⊂CB[7] assembly due to the formation of different assembly modes. The multicolor long‐lived emission has been demonstrated very well based on the TS‐FRET process activated by CB[8] macrocyclic confined 2D organic framework, which can be successfully applied to fingerprint imaging and the construction of logic gate systems. It provides a novel method for supramolecular macrocycle confined phosphorescence regulation and the development of luminescent materials. [ABSTRACT FROM AUTHOR]

Organic photoluminescent materials with room‐temperature phosphorescence (RTP) are of great interest, yet achieving RTP in hydrogels faces challenges due to water‐quenching effects. In this study, a straightforward method is presented to achieve RTP hydrogel using a self‐healing and salt‐hardening hydrogel. The hydrogel is synthesized by polymerizing acrylic acid (AA) with diethylenetriamine (DETA) as the dynamic crosslinker. The poly(acrylic acid)/DETA hydrogel could achieve an afterglow lasting 1.6 s after soaking with NaBr solution. The salt‐enhanced hydrophobic aggregation of the hydrogel network promotes the clustering of carboxyl groups and oxygen atoms, resulting in a rigid environment that suppresses nonradioactive transitions and leads to the manifestation of RTP. Additionally, the dynamic association of AA‐DETA allows the freeze‐dried hydrogel powder to be blended with various hydrophobic dyes, leading to a remodelable hydrogel with delayed emission of multiple colors. In general, by combining salt‐hardening property with self‐healing property together, a RTP hydrogel platform that can be facilely loaded with various organic dyes is proposed. [ABSTRACT FROM AUTHOR]

Supramolecular organic framework (SOF) has recently garnered significant research interest in the field of luminescent materials. However, SOF with room‐temperature phosphorescence emission in solution is very rare due to the quenching of dissolved oxygen and free molecular motions, which would lead to nonradiative deactivation of triplet exciton in liquid state. In this work, a 3D cationic phosphorescent SOF is synthesized through host‐guest interaction between CB[8] and a tetrahedral monomer TBBP, which can rapidly adsorb anionic guests in solution. When anionic dyes are introduced, triplet to singlet Förster resonance energy transfer (TS‐FRET) in solution can be achieved, and delayed fluorescence with large Stokes shift can be realized. Additionally, when anionic drugs are introduced, the phosphorescence of TBBP‐CB[8] can be quenched due to charge transfer, enabling the detection of drugs through phosphorescence signals. Taking advantage of the fast adsorption property of 3D SOF, an INHIBIT logic gate with three inputs and two outputs is constructed. These findings provide a novel method to prepare phosphorescent functional materials and a new pathway to construct TS‐FRET system in solution. [ABSTRACT FROM AUTHOR]

Despite rapid progress and wide applications of room temperature phosphorescence (RTP) materials, it is still a great challenge to optimize the RTP activity through rational structural design at a molecular level. Herein, a successful cationic engineering strategy is demonstrated to modulate the crystal flexibility achieving controllable RTP in a new pair of metal halides [APML]ZnCl4 ([APML] = N‐(3‐Aminopropyl)morpholine) and [AEML]ZnCl4 ([AEML] = N‐(2‐Aminoethyl)morpholine). Both halides display blue fluorescence under 365 nm UV. Comparing with longer [APML]+, shorter [AEML]+ significantly enhances crystal rigidity and restrains non‐radiative scattering, boosting photoluminescence quantum yield (PLQY) from 18.89% to 22.41%. Synchronously, enhanced crystal rigidity significantly promotes the inter‐system crossing from singlet to triplet excited states. As a consequence, [AEML]ZnCl4 displays long‐lived green RTP property with millisecond scale lifetime in contrast to the blank RTP activity of [APML]ZnCl4. Comprehensive investigations demonstrate that the energy transfer between inorganic and organic components greatly changes the redistribution of singlet and triplet excited states, resulting in distinct phosphorescence activity. The different short‐lived blue fluorescence and long‐lived green phosphorescence provide a color‐time‐dual‐resolved luminescent tag with advanced applications in anti‐counterfeiting, etc. This work highlights a new structural engineering strategy to achieve controllable RTP affording a guide to rationally design RTP materials. [ABSTRACT FROM AUTHOR]

Organic room‐temperature phosphorescence (RTP) materials are actively explored as attractive candidates for optoelectronic and bioelectronics applications given their unique long‐lived excited‐state features and inherent merits of low‐cost, appreciable functionality, and good biocompatibility. In recent years, many efforts in molecular design and aggregation modulation are devoted to achiev efficient RTP from organics, among which an emerging strategy focuses on confining chromophores within polymer matrices. Polymers possess intertwined chains making them a good platform to restrain the nonradiative decays and quenching, allowing the triplet excitons to survive a long time enough for emission at room temperature. Progress relating to polymer‐based organic RTP materials is highlighted as a new creative subject in the field. This review outlines recent advancements in polymer‐based organic RTP materials. The fundamental mechanism of organic RTP is first presented. Thereafter, design considerations and strategies to construct polymer‐based organic RTP materials are summarized in detail. Several promising progresses in the proposed use of these RTP materials, such as encryption and anti‐counterfeiting, sensors, and bioimaging are overviewed. Finally, the challenges and future perspectives are discussed to emphasize the directions that deserve focus attention in the field. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Kasha's exciton model proposes that T1 energy levels of organic compounds are insensitive to molecular aggregation and microenvironment change because of negligible small transition dipole moments of T1 states. This model holds true in most organic systems till now. Here we report the fabrication of twisted organic phosphors with intramolecular charge transfer characters and flexible molecular structures. When doped into different organic matrices, the twisted phosphor adopts different conformation, exhibits distinct phosphorescence colors and T1 energy levels, which violates Kasha's exciton model in organic system. Given that the change of phosphorescence colors and maxima can be readily distinguished by human eyes and conventional instrument, the twisted phosphors would be exploited as a new type of molecular probe, which would exhibit potential application in optical sensing and stimuli‐responsive systems. [ABSTRACT FROM AUTHOR]

Organic scintillators have recently gained considerable attentions in X‐ray detection for their potential applications in biomedical radiograph and security inspection. However, the weak X‐ray absorption and/or inefficient exciton utilization have limited the development and commercialization of organic scintillators. Currently, high‐performance X‐ray organic scintillators are scarce and organic scintillators with dual triplet‐harvesting channels have not been explored before. Here, we develop several proof‐of‐concept sulfone‐based organic molecules, C1–C7, using different alkoxy chains to manipulate molecular packing mode. These materials exhibit dual triplet‐harvesting channels of thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP) in aggregated state. Inspiringly, these molecules display distinct radioluminescence under the X‐ray stimulation. Among them, C6 behaves the highest light yield of 16,558 photons MeV−1. Moreover, clear X‐ray images are demonstrated in both aggregated state and single‐molecule level. High spatial resolutions of 15.0 and 10.6 line pairs per millimeter (lp mm−1) are achieved for rigid and flexible scintillator screens, exceeding most reported organic and conventional inorganic scintillators. These results highlight the great potential of organic molecules with TADF and RTP nature for efficient X‐ray scintillation and imaging. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Supramolecular room temperature phosphorescence (RTP) materials are attractive due to their excellent RTP characteristics and water resistance. By evaluating the photophysical properties of HA/BisNpI‐doped materials, it is proved that hyaluronic acid (HA) is a promising matrix and the rigid plane N,N′‐(1,4‐phenylene)‐bis(1,8‐naphthalimide) (Ph‐BisNpI) is an excellent luminescent guest molecule for constructing RTP materials. Moreover, it is found that γ‐cyclodextrin (γ‐CD) can successfully bind BisNpI guest molecule. Accordingly, a tightly arranged ternary supramolecular system with HA as matrix, Ph‐BisNpI as the guest, and γ‐CD as the host is constructed by host‐guest interaction and hydrogen bonding. As expected, the obtained ternary supramolecular system HA/Ph@CD8 displays a superior RTP performance (52.7 ms longer lifetime than HA/Ph), water‐resistance, and even aqueous RTP (τ = 207 µs), which significantly extends the application of RTP in aqueous solution. These results are possibly attributed to the inclusion of γ‐CD on Ph‐BisNpI guest molecules and the self‐assembly of γ‐CD and HA to form a rigid hydrogen bonding network, which effectively inhibits the non‐radiative decay of Ph‐BisNpI and shields the triplet excitons from water and oxygen. Furthermore, the prepared ternary supramolecular RTP materials are successfully used as anticounterfeiting ink and exhibit broader application prospects in water environments. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In purely organic room‐temperature phosphorescence (RTP) materials, fluorescence radiative transitions generally compete against inter‐system crossing (ISC) transitions to give fluorescence/phosphorescence dual emission. In order to achieve pure phosphorescence in RTP organic light‐emitting diodes (OLEDs), extended π‐conjugation is introduced into Se‐containing donors to suppress the fluorescence radiative transitions by the symmetry excited state orbitals in the introduced π–π* transitions that cancel the overlap of the orbitals, and two novel nonaromatic amine donor containing orange RTP emitters namely 2‐(benzo[c]phenoxaselenin‐10‐yl)‐4,6‐diphenyl‐1,3,5‐triazine (BPXSeDRZ) and 2‐(dibenzo[a,c]phenoxaselenin‐11‐yl)‐4,6‐diphenyl‐1,3,5‐triazine (DBPXSeDRZ) are developed, both of which exhibit efficient orange pure phosphorescence in doped films thanks to the sufficient ISC transitions. As a result, high external quantum efficiencies of 17.2% and 17.9% are respectively achieved for the orange RTP‐OLEDs based on BPXSeDRZ and DBPXSeDRZ for the first time, and they also exhibit stable pure electro‐phosphorescence spectra in a wide driving voltage. Moreover, by adopting DBPXSeDRZ as a sensitizer to harvest the triplet excitons and tetraphenyldibenzoperiflanthene as a conventional fluorescent emitter, the external quantum efficiency of the sensitized red fluorescent OLED can be elevated to 10.1%, which greatly expands the potential applications of the metal‐free phosphors in OLEDs. [ABSTRACT FROM AUTHOR]

The development of a persistent luminescence system with long‐lived phosphorescence and color‐tunable afterglow at room temperature represents a challenge, largely due to the intensive non‐radiative deactivation pathway. In this study, an ultralong‐lived room temperature phosphorescence (RTP) system has been achieved using a hydrogen‐bonding strategy where poly(vinyl alcohol) (PVA) matrices were doped with tryptophan (Trp) derivatives. The PVA film doped with N‐α‐(9‐Fluorenylmethoxycarbonyl)‐L‐tryptophan (Fmoc‐L‐Trp) exhibited a long‐lived phosphorescence emission of up to 3859.70 ms, and a blue afterglow for a duration greater than 34 s, under ambient conditions. The introduction of two other fluorescent dyes (i. e. Rhodamine B and Basicred14) to the PVA film facilitates adjustment to the color of the afterglow from blue to orange, and pink, by a triplet‐to‐singlet Förster‐resonance energy transfer (TS‐FRET) process. These films have been successfully applied in silk‐screen printing and in multicolor afterglow light‐emitting diode (LED) arrays. [ABSTRACT FROM AUTHOR]

In order to improve the performance of organic luminescent materials, lots of studies have been carried out at the molecular level. However, these materials are mostly applied as solids or aggregates in practical applications, in which the relationship between aggregation structure and luminescent property should be paid more attention. Here, we obtained five phenothiazine 5,5‐dioxide (O‐PTZ) derivatives with distinct molecular conformations by rational design of chemical structures, and systematically studied their room‐temperature phosphorescence (RTP) effect in solid state. It was found that O‐PTZ dimers with quasi‐equatorial (eq) conformation tended to show stronger π‐π interaction than quasi‐axial (ax) conformers in crystal state, which was more conducive to the generation of RTP. Based on this result, a multi‐level structural model of organic solids was proposed to draw the relationship between aggregation structure and RTP effect, just like the research for the structure‐property relationship of proteins. Using this structural model as the guide, boosted RTP efficiency from 1% to 20% was successfully achieved in the corresponding host‐guest doping system, showing its wide applicability. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescent (CPL) materials have significant promising applications in organic light‐emitting diodes, asymmetric synthesis, and other fields. However, due to the instability of triplet‐state excitons, how to achieve an effective combination of CPL with room‐temperature phosphorescence (RTP) remains a formidable challenge. Here, a simple and feasible method for constructing polymer‐based CPRTP materials is proposed by preparing chiral phosphorescent liquid crystals through copolymerization. A series of RTP chiral liquid crystal copolymers are successfully synthesized by copolymerizing phosphorescent monomer bearing chiral cholesterol mesogen with phosphorescent monomer bearing dibenzofuran chromophore. Due to the introduction of chiral cholesterol mesogen, copolymers can form chiral smectic C‐phase liquid crystals. Utilizing their selective reflection characteristic, efficient CPRTP is achieved, with a glum value of up to −1.6 × 10−2. In addition, both components in copolymers exhibit RTP properties and show significant differences in phosphorescence color and lifetime. By changing the composition of copolymers, the regulation of their phosphorescence properties is successfully achieved. As a result, multicolor‐tunable and time‐dependent CPRTP materials are successfully prepared. [ABSTRACT FROM AUTHOR]

Tautomers coexisting in an equilibrium system have significant potential for regulating luminescent properties because of their structural differences. However, separating and stabilizing tautomers at room temperature is a considerable challenge. In this study, it is found that hydrogen‐bonded organic frameworks (HOFs) composed of Br‐ anions can effectively separate and stabilize two proton‐transfer tautomers of triarylformamidinium bromide: namely, the nitrogen cation (BA‐N) and carbon cation (BA‐C). The BA‐N crystal consisting of a dense anionic HOF and parallelly aligned organic cations exhibits green thermally activated delayed fluorescence and red room‐temperature phosphorescence (RTP). The BA‐C crystal contains acetone molecules that induce an antiparallel arrangement of the organic cations to form a loose HOF, producing blue prompt fluorescence and green RTP. Interestingly, switching of the HOFs between BA‐N and BA‐C can be achieved through the uptake and release of acetone, thereby dynamically adjusting multiple luminescent properties. Consequently, the HOF crystals can be used for the highly sensitive and specific sensing of acetone with a detection limit of 66.74 ppm. This study not only stabilizes tautomeric luminescent materials at room temperature, but also provides a new method for constructing smart HOFs with a sensitive response to a stimulus. [ABSTRACT FROM AUTHOR]

Achieving circularly polarized organic ultralong room‐temperature phosphorescence (CP‐OURTP) with a high luminescent dissymmetry factor (glum) is crucial for diverse optoelectronic applications. In particular, dynamically controlling the dissymmetry factor of CP‐OURTP can profoundly advance these applications, but it is still unprecedented. This study introduces an effective strategy to achieve photoirradiation‐driven chirality regulation in a bilayered structure film, which consists of a layer of soft helical superstructure incorporated with a light‐driven molecular motor and a layer of room‐temperature phosphorescent (RTP) polymer. The prepared bilayered film exhibits CP‐OURTP with an emission lifetime of 805 ms and a glum value up to 1.38. Remarkably, the glum value of the resulting CP‐OURTP film can be reversibly controlled between 0.6 and 1.38 over 20 cycles by light irradiation, representing the first example of dynamically controlling the glum in CP‐OURTP. [ABSTRACT FROM AUTHOR]

Purely organic materials exhibiting room temperature phosphorescence (RTP) are promising candidates for oxygen sensors and information encryption owing to their cost‐effective and environmentally friendly nature. Herein, we report a bimolecular RTP system where DTBU acts as the guest and TBBU serves as the host. In contrast to previously reported results, we find that both pure DTBU and TBBU do not exhibit RTP in the solid state even under N2 atmosphere. A DTBU/TBBU system with a low doping ratio (0.1 mol %) exhibits persistent yellowish‐green afterglow with a lifetime of 340 ms and is highly sensitive to oxygen. A DTBU/TBBU system with a higher doping ratio (10 mol %) maintains a phosphorescence lifetime of 179 ms under air. Applications of DTBU/TBBU at varied doping ratios in both oxygen sensing and information encryption are demonstrated. We propose that the T1 state of TBBU acts as an energy transfer intermediate between Tn and T1 of DTBU, ultimately leading to the generation of persistent RTP. Overall, this work demonstrates the critical importance of material purity in the design of RTP systems, and how an understanding of host–guest doping enables their photophysical properties to be precisely tuned. [ABSTRACT FROM AUTHOR]

Organic materials with room‐temperature phosphorescence (RTP) are in high demand for optoelectronics and bioelectronics. Developing RTP materials highly relies on expert experience and costly excited‐state calculations. It is a challenge to find a tool for effectively screening RTP materials. Herein we first establish ground‐state orbital descriptors (πFMOs) derived from the π‐electron component of the frontier molecular orbitals to characterize the RTP lifetime (τp), achieving a balance in screening efficiency and accuracy. Using the πFMOs, a data‐driven machine learning model gains a high accuracy in classifying long τp, filtering out 836 candidates with long‐lived RTP from a virtual library of 19,295 molecules. With the aid of the excited‐state calculations, 287 compounds are predicted with high RTP efficiency. Impressively, experiments further confirm the reliability of this workflow, opening a novel avenue for designing high‐performance RTP materials for potential applications. [ABSTRACT FROM AUTHOR]

The accurate thermosensing requires a minimum impact of autofluorescence and light scattering from the samples. In this study, we discovered that commercially available benzene‐1,4‐diboronic acid (BDBA) doped co‐crystals with trimethylolpropane (TMP) exhibit excellent thermochromic dual phosphorescence properties over a wide temperature range from −132 to 40 °C, despite its simple structure that does not have any donor‐acceptor linkage. The dual phosphorescence was consisted of monomeric benzene‐1,4‐diboronate (BDBA ester) and aggregation‐stabilized species. With an increase in temperature, the emission intensity from the monomeric state significantly decreased, whereas that originating from the aggregated state remained almost constant owing to the difference in their thermal stabilities. Further investigation revealed that molecular distortions in singlet excited states enable efficient intersystem crossing, causing efficient phosphorescence from the monomeric state of BDBA ester. [ABSTRACT FROM AUTHOR]

Long‐lived room‐temperature phosphorescence (RTP) materials have been widely applied in various fields. However, achieving high‐performance carbon dots (CDs) RTP remains a great challenge. Here, a facile synthetic strategy is rationally designed for the synthesis of high‐performance dual‐mode emitting CDs by constructing rigid structures through the synergistic effect of the matrices. The obtained CD RTP powder possesses an ultrahigh photoluminescence quantum yield (PLQY) of 70.7%, a phosphorescence lifetime of about 0.45 s, and an afterglow that lasts for 15 s to the naked eyes. Most importantly, the prepared CD RTP powder can be utilized as a commercial phosphor powder for the fabrication of a high‐performance white lighting‐emitting diode (WLED) with a CIE coordinate of (0.39, 0.39), a high color rendering index of 93.6, and a color temperature of 3805 K for warm WLED. Especially the luminous efficiency of the fabricated WLED can reach up to 66.89 lm W−1, which is much higher than the values reported for most CDs‐based WLED devices. Additionally, CD RTP can be applied to advanced invisible inks for information encryption due to its excellent water solubility and can also be exploited for advanced information anti‐counterfeiting by utilizing phosphorescent properties. [ABSTRACT FROM AUTHOR]

Colloidal carbon dots (C‐dots) are considered as promising heavy‐metal‐free materials to achieve room‐temperature phosphorescence (RTP) properties for promising applications, such as photoelectronic devices, information encryption, and bio‐imaging. However, most of the current obtained RTP C‐dots have a short lifetime with a relatively low quantum yield (QY). In this work, the C‐dots large‐scale synthesized via a vacuum heating approach have multiple RTP emissions (blue, green, and yellow), a long RTP lifetime of as high as 1.92 s, and a high QY of 34.4% by selecting different types of precursors, which is superior to most of reported RTP C‐dots. The multiple atoms doping and strong bonding between neighbored C‐dots promoted by vacuum heating contributes to the excellent RTP properties. As a proof‐of‐concept, the as‐obtained RTP C‐dots are used as optical ink for flexible security codes, exhibiting a bright shape with a lifetime of 1.37 s. This work offers an efficient approach for producing large‐scale high‐quality RTP C‐dots, which can be applied to anti‐counterfeiting and information encryption systems. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Monitoring of sweat pH plays important roles in physiological health, nutritional balance, psychological stress, and sports performance. However, the combination of functional MOFs with phosphorescent material to acquire the real‐time physiological information, as well as the application of dual mode anti‐counterfeiting, has seldom been reported. Herein, we developed multifunctional gel films based on MOFs and phosphorescent dyes which responded to H+ ions and the related mechanism was studied in detail. Upon exposure to H+, the composite gel film exhibited decreased fluorescent signal but enhanced room temperature phosphorescence (RTP), which could be utilized for sweat pH sensing through a dual‐mode. Moreover, multifunctional gel films exhibited a potential application in information encryption and anti‐counterfeiting by designing of stimulus responsive multiple patterns. This research provided a new avenue for portable and non‐invasive sweat pH monitoring methods while also offering insights into stimulus‐responsive multifunctional materials. [ABSTRACT FROM AUTHOR]

Pure organic persistent room‐temperature phosphorescence (p‐RTP) materials have attracted rapidly growing attention due to their unique photophysical properties and wide potential practical applications. However, most of the reported pure organic p‐RTP materials have low quantum yields and short lifetimes, and many p‐RTP compounds contain large π‐conjugated structures, which are difficult and complex to synthesize. Herein, a series of triazole derivatives with efficient p‐RTP emissions is reported. 2H‐1,2,3‐triazole‐4,5‐dicarboxylic acid (TDAc) is first found to exhibit green RTP under 312 nm excitation. Then, a series of ionized products of TDAc and their isomers with red‐shifted RTP emissions are further obtained by ionization of TDAc. Among them, the sodium 2H‐1,2,3‐triazole‐4‐carboxy‐5‐carboxylate can emit RTP with an ultra‐long phosphorescence lifetime (3.25 s) and high photoluminescence (PL) and p‐RTP quantum yields of 31.3% and 14.2%, respectively, as well as mechanorochromic behavior. Experimental results and theoretical calculations prove that strong intra‐/intermolecular interactions including hydrogen bonding and ionic bonding promote the overlap of molecular orbitals to form effective through‐space conjugation (TSC) and greatly stabilize the conformations, thus achieving efficient p‐RTP emissions. This work provides a simple and efficient strategy for designing p‐RTP compounds with high quantum yields. [ABSTRACT FROM AUTHOR]

Polymer‐based organic room‐temperature phosphorescent (RTP) materials have recently attracted significant attention. In most of the previous works, 'chemical approaches' were applied to improve the performance of RTP materials, such as designing certain phosphors or selecting specific polymeric matrixes. However, enhancing triplet emission through facile 'physical approaches' is rarely reported. In this study, enhanced RTP emissions of phosphor‐doped polymers are reported by thermal annealing. By doping a difluoroboron β‐diketonate derivative into poly(diacetone acrylamide) (PDAAM), green RTP emissions can be obtained. After thermal annealing at 125 °C for 5 min, the afterglow duration of RTP increases from 2.6 to 5.3 s and also the brightness of RTP emission exhibits a threefold increase. Such post‐treatment is applicable for various polymeric matrixes. The mechanism underlying thermal‐annealing enhanced RTP is investigated. Moreover, it demonstrates that controlled RTP by thermal annealing can be used in information encryption and anti‐counterfeiting. This work provides new insight into the development of organic RTP materials with tunable emissions. [ABSTRACT FROM AUTHOR]

Room temperature phosphorescent (RTP) materials have triggered wide interests because of their excellent performance and various promising applications. However, conventional RTP materials possessing color‐tunable and ultralong afterglow often suffer from low phosphorescent emission efficiency. Herein, a long lifetime and high‐efficiency RTP emission system composed of boric acid as the host matrix and organic phosphors as guest molecules is constructed by suppressing the non‐radiative transition process and promoting the triplet exciton of the phosphors. The synergistic effect of the physically limited domain and supramolecular anchoring also contributes to the ultralong lifetime (up to 1.85 s) and high phosphorescence quantum yield (up to 53%). The afterglow can be visually observed for 30 s. With a large overlap of π‐conjugated chromophores, the emission peak of RTP redshifted, realizing cyan, green, and red afterglow in the monochromatic domain. In addition, the emission of colorful afterglow and white afterglow is adjustable with the different co‐doping ratios. Finally, the application of RTP materials to anti‐counterfeiting encryption is demonstrated. [ABSTRACT FROM AUTHOR]

Organic room temperature phosphorescence materials (RTP) have attracted much attention for their wide application in organic light‐emitting diodes, anti‐counterfeiting, and sensors. In this work, a series of organic luminogens containing carbonyl and aromatics were fixed in a three‐dimensional polymethyl methacrylate (PMMA) network by in situ polymerization. All organic luminogens‐doped in situ PMMA (s‐PMMA) columns achieved longer RTP lifetimes than those of doped commercial PMMA (c‐PMMA) films, especially, the RTP lifetime of NMP2O in these PMMA matrixes increased from 1.82 ms to 156.34 ms by about 86 times. It is mainly due to the restriction of molecular motions by highly entangled polymer chains and rigid environments to efficiently inhibit the non‐radiative transitions. Also, the excellent shielding effect toward oxygen by the in situ polymerization process can avoid possible quenching effects on triplet excited states, beneficial to RTP emission. Thus, it affords an efficient approach to achieving persistent RTP for three‐dimensional displaying applications. [ABSTRACT FROM AUTHOR]

Research of thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP) materials is attractive owing to their extensive applications in various fields. However, achieving organic TADF and RTP materials, particularly those with stimulus‐responsiveness and tunability, is highly desirable but challenging and rarely reported. Herein, two easily synthesized organic molecules are reported with abnormal stimulus‐responsive switchable TADF and RTP effects, in which phenothiazine (PTZ) and benzo[b]phenothiazine (BPTZ) based donor−acceptor molecules PTZ‐DBQ and BPTZ‐DBQ show mechanical‐induced TADF in crystalline phase and photo‐responsive RTP in doping poly(methyl methacrylate) (PMMA) films. This is the first time tetracyclic BPTZ has been used as a donor in achieving TADF and RTP materials, and it is found that BPTZ‐DBQ exhibits remarkably better photophysical properties than PTZ‐DBQ. Systematic studies of experimental results and theoretical calculations indicate that the conformational heterogeneity plays an essential role in achieving mechanical‐induced TADF with mechanochromic luminescence (MCL) property. Embedding the organic phosphors into rigid polymer matrices effectively suppresses the molecular motion, thus turning on the RTP emission channel. The conversion of 3O2 to 1O2 under UV irradiation is mainly responsible for the photo‐induced process. These multifunctional luminescent materials have great potential applications in chemical sensors, information encryption, and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Ultralong organic room‐temperature phosphorescence (RTP) materials, especially high‐energy blue emission materials, have attracted tremendous attention but remain difficult to achieve. Here, a strategy based on the multi‐hydrogen bonds enhanced anchoring effect is developed to activate single‐molecule blue phosphorescence emission with the highest efficiency of 29.79%. Specifically, the aromatic electrophilic directing (AED) effect provides a rational explanation for the structural spectral change. The construction of artificial light‐harvesting systems via physical blending achieves on‐demand modulation for afterglow color, including white afterglow. Furthermore, cold‐white emission is also achieved via a structural π‐extension optimization strategy. Moreover, the high transmittance and reversible water‐sensitivity render these polymer films with applicability as smart organic optoelectronic materials. [ABSTRACT FROM AUTHOR]

Organic materials showing reversible changes in persistent room‐temperature phosphorescence (RTP) upon exposure to external stimuli have attracted considerable attention in recent years. One potentially groundbreaking development in this area is the introduction of the gating concept for organic persistent RTP materials. This refers to a material where a desired responsive ability only occurs when it is triggered by a specific stimulus, but it remains a formidable challenge. In this study, photoirradiation‐gated excitation‐dependent (Ex‐De) persistent RTP is achieved. A series of molecules, triphenylphosphine and carbazole derivatives connected through flexible carbon chains, are designed and prepared. Upon removal of ultraviolet (UV) irradiation, all these compounds doped polyvinyl alcohol (PVA) films exhibit obvious blue or green afterglow RTP. Among them, (2‐(9H‐[3,9′‐bicarbazol]−9‐yl)ethyl)triphenylphosphonium bromide (TPP‐2C‐Cz) doped PVA film initially exhibits blue persistent RTP after removal of 300 nm excitation but no RTP upon ceasing 365 nm irradiation. Interestingly, upon UV irradiation with a power density of 0.05 W cm−2 (UVA) for 50 min, the Ex‐De RTP behavior of TPP‐2C‐Cz doped PVA film is activated. Eventually, photoirradiation‐gated Ex‐De afterglow emission will be used for a wide range of applications, including the quantitative determination of UV irradiation dose and the permanent record of UV irradiation history, and read on‐demand. [ABSTRACT FROM AUTHOR]

Organic photoluminescent materials exhibiting room‐temperature phosphorescence (RTP) have attracted widespread attention. However, most of them can emit phosphorescence only in the solid state, which strongly limits their applications. Herein, a type of phosphorescent hydrogel with excellent mechanical properties is prepared by immersing an as‐prepared poly(vinyl alcohol) (PVA) hydrogel in a poly(sodium maleate) solution and then in a CaCl2 solution, followed by drying under stretching at 90 °C and finally soaking it in deionized water until equilibrium swelling to produce poly(vinyl alcohol)/poly(calcium maleate)‐DS (PVA/PMACa‐DS) hydrogels. Such hydrogels exhibit excellent mechanical properties, showing tensile strengths up to 15 MPa, due to the presence of strong hydrogen bonding and especially ionic bonding. The PVA/PMACa‐DS hydrogels emit varied phosphorescence emission colors from blue to yellow‐green upon excitation with 312–400 nm light, with a maximum lifetime of 13.4 ms. Experiments and theoretical calculations demonstrate that ionic crosslinking between Ca2+ and nonconventional chromophores prevents the contact of the nonconventional chromophores with water molecules and hence restricts nonradiative decay, leading to RTP emission. This work provides a reliable strategy for designing RTP hydrogels with excellent mechanical properties based on nonaromatic polymers for emerging applications. [ABSTRACT FROM AUTHOR]