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Ultralong organic phosphorescence (UOP) is essential for potential applications in bioelectronics and optoelectronics. However, the precise design of UOP materials remains a formidable challenge. Herein, a facile strategy is presented to confine dimeric chromophores for triggering UOP emission, based on the manipulation of the carbonyl, sulfonyl, and amino groups within organic phosphors. The experimental data reveal that saccharin analogs in crystals containing dimeric chromophores, confined by the (3D) hydrogen‐bonded networks, exhibit ultralong emission lifetime of up to 635 ms under ambient conditions. Whereas for saccharin analogue crystals lacking dimeric chromophores, the lifetime decreases to 54 ms, resulting in the absence of UOP emission. Moreover, the non‐toxic saccharin crystals with UOP have succeeded in drug anti‐counterfeiting. These findings will open a novel avenue for the design UOP materials and broaden the domain of UOP to diverse applications. [ABSTRACT FROM AUTHOR]

Carbonaceous materials are promising anode candidates for potassium‐ion batteries (PIBs) given its high conductivity, stable property, and abundant resource, while its practical implementation is still hampered by its limited capacity and inferior rate behavior. Herein, we report a superior carbonaceous anode through a combined strategy of carbon hybridization and heteroatom doping. In this composite, hollow carbon spindles (HCS) were anchored on the surface of graphene (G) followed with sulfur doping treatment, aiming to integrate the high conductivity of graphene, the good structure stability of HCS, and the S doping‐induced ample active sites. As a PIB anode, the S‐G@HCS composite can display high capacity (301 mA h g−1 at 0.1 A g−1 after 500 cycles) and long‐term cyclability up to 1800 cycles at 2 A g−1. Impressively, it can deliver an outstanding rate capacity of 215 mA h g−1 at 10 A g−1, which is superior to most carbon anodes as‐reported so far for PIBs. Experimental and theoretical analysis manifests that the construction of graphene/amorphous carbon interface as well as S doping enables the regulation of electronic structure and ion adsorption/transportation properties of carbonaceous material, thus accounting for the high capacity and superior rate capability of S‐G@HCS composite. [ABSTRACT FROM AUTHOR]

Amorphous purely organic phosphorescence materials with long-lived and color-tunable emission are rare. Herein, we report a concise chemical ionization strategy to endow conventional poly(4-vinylpyridine) (PVP) derivatives with ultralong organic phosphorescence (UOP) under ambient conditions. After the ionization of 1,4-butanesultone, the resulting PVP-S phosphor showed a UOP lifetime of 578.36 ms, which is 525 times longer than that of PVP polymer itself. Remarkably, multicolor UOP emission ranging from blue to red was observed with variation of the excitation wavelength, which has rarely been reported for organic luminescent materials. This finding not only provides a guideline for developing amorphous polymers with UOP properties, but also extends the scope of room-temperature phosphorescence (RTP) materials for practical applications in photoelectric fields., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Provided here is evidence showing that the stacking between triplet chromophores plays a critical role in ultralong organic phosphorescence (UOP) generation within a crystal. By varying the structure of a functional unit, and different on-off UOP behavior was observed for each structure. Remarkably, 24CPhCz, having the strongest intermolecular interaction between carbazole units exhibited the most impressive UOP with a long lifetime of 1.06 s and a phosphorescence quantum yield of 2.5 %. 34CPhCz showed dual-emission UOP and thermally activated delayed fluorescence (TADF) with a moderately decreased phosphorescence lifetime of 770 ms, while 35CPhCz only displayed TADF owing to the absence of strong electronic coupling between triplet chromophores. This study provides an explanation for UOP generation in crystal and new guidelines for obtaining UOP materials., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Although carborane-based luminescent materials have been studied for years, no persistent phosphor has been reported so far. Herein, we describe boron-cluster-based persistent phosphors obtained by linking a σ-aromatic carboranyl cage to the π system of a carbazolyl group. The carboranes were found to promote intersystem crossing from a singlet to a triplet state. The rigid boron cluster was able to stabilize the ultralong triplet excitons through multiple nonclassical hydrogen bonds, such as B-H⋅⋅⋅π interactions, thus leading to a long lifetime of up to 0.666 s and an absolute phosphorescence quantum yield of 7.1 %, which is outstanding for an organic phosphor without heavy atoms. These phosphors can be excited by visible light and show dynamic emission behavior, including thermochromism and mechanochromism. This study demonstrates that non-metal/heavy-atom boron clusters can be used to develop multifunctional high-performance phosphors for potential applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Smart materials with ultralong phosphorescence are rarely investigated and reported. Herein we report on a series of molecules with unique dynamic ultralong organic phosphorescence (UOP) features, enabled by manipulating intermolecular interactions through UV light irradiation. Our experimental data reveal that prolonged irradiation of single-component organic phosphors of PCzT, BCzT, and FCzT under ambient conditions can activate UOP with emission lifetimes spanning from 1.8 to 1330 ms. These phosphors can also be deactivated back to their original states with short-lived phosphorescence by UV irradiation for 3 h at room temperature or through thermal treatment. Additionally, the dynamic UOP was applied successfully for a visual anti-counterfeiting application. These findings may provide unique insight into dynamic molecular motion for optical processing and expand the scope of smart-response materials for broader applications., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Ultralong organic phosphorescence (UOP) based on metal-free porous materials is rarely reported owing to rapid nonradiative transition under ambient conditions. In this study, hydrogen-bonded organic aromatic frameworks (HOAFs) with different pore sizes were constructed through strong intralayer π-π interactions to enable ultralong phosphorescence in metal-free porous materials under ambient conditions for the first time. Impressively, yellow UOP with a lifetime of 79.8 ms observed for PhTCz-1 lasted for several seconds upon ceasing the excitation. For PhTCz-2 and PhTCz-3, on account of oxygen-dependent phosphorescence quenching, UOP could only be visualized in N 2 , thus demonstrating the potential of phosphorescent porous materials for oxygen sensing. This result not only outlines a principle for the design of new HOFs with high thermal stability, but also expands the scope of metal-free luminescent materials with the property of UOP., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new type of materials, organic salts in the crystal state, have ultralong organic phosphorescence (UOP) under ambient conditions. The change of cations (NH 4 + , Na + , or K + ) in these phosphors gives access to tunable UOP colors ranging from sky blue to yellow green, along with ultralong emission lifetimes of over 504 ms. Single-crystal analysis reveals that unique ionic bonding can promote an ordered arrangement of organic salts in crystal state, which then can facilitate molecular aggregation for UOP generation. Additionally, reversible ultralong phosphorescence can be realized through the alternative employment of fuming gases (ammonia and hydrogen chloride), demonstrating its potential as a candidate for visual ammonic or hydrogen chloride gas sensing. The results provide an environmental responsible and practicable synthetic approach to expanding the scope of ultralong organic phosphorescent materials as well as their applications., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)