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White light, which contains polychromic visible components, affects the rhythm of organisms and has the potential for advanced applications of lighting, display, and communication. Compared with traditional incandescent bulbs and inorganic diodes, pure organic materials are superior in terms of better compatibility, flexibility, structural diversity, and environmental friendliness. In the past few years, polychromic emission has been obtained based on organic aggregates, which provides a platform to achieve white-light emission. Several white-light emitters are sporadically reported, but the underlying mechanistic picture is still not fully established. Based on these considerations, we will focus on the single-component and multicomponent strategies to achieve efficient white-light emission from pure organic aggregates. Thereinto, single-component strategy is introduced from four parts: dual fluorescence, fluorescence and phosphorescence, dual phosphorescence with anti-Kasha's behavior, and clusteroluminescence. Meanwhile, doping, supramolecular assembly, and cocrystallization are summarized as strategies for multicomponent systems. Beyond the construction strategies of white-light emitters, their advanced representative applications, such as organic light-emitting diodes, white luminescent dyes, circularly polarized luminescence, and encryption, are also prospected. It is expected that this review will draw a comprehensive picture of white-light emission from organic aggregates as well as their emerging applications.

Due to the fast dynamics and re-equilibration of supramolecular self-assembly, bottom-up molecular strategies to fabricate well-defined and controllable multiblock structures are rare. Herein, we propose a new concept for fabrication of fluorescent multiblock microcolumns containing 1 to 7 blocks via hierarchical supramolecular self-assembly based on cucurbit[8]uril (CB[8]), NaBr and an AIEgen guest. Through the complexation between CB[8] and different numbers of AIEgen guests (2, 1, 0), the competitive displacement caused by the binding of the sodium cation to the CB[8] portal, and the reversible assembly of positively charged guests in salt solutions, one-pot hierarchical supramolecular self-assembly is realized. The molecular structure of each block is analyzed by single-crystal X-ray diffraction. The AIEgen enables the self-assembly of multiblocks to be visualized, understood, and regulated. © 2022 Wiley-VCH GmbH.

Materials showing metallophilic interactions continue to attract considerable theoretical and experimental attention largely because of their unusual and unanticipated photophysical behavior as well as their unique stimuli-responsive behavior in an aggregate or solid state. Metallophilic interactions are mostly found between metals with either identical (d10–d10) or different (s2–d8, d8–d10) configurations. Among various metallophilic interactions, aurophilic interactions (Au⋯Au) are well-known and widely reported. In this study, a new phosphorescent gold(I) complex, [(CF3Ph)3PAuC≡CPh] (TPPGPA) was reported. The crystal structure of TPPGPA demonstrated the formation of trimers caused by intermolecular aurophilic interactions. These trimeric crystals showed an efficient and nearly pure white-light emission with Commission Internationale de L’Eclairage 1931 chromaticity coordinates of (0.33, 0.34) at ambient conditions. Moreover, TPPGPA displayed fascinating mechanochromic and thermochromic luminescence properties in the crystalline state. The application of TPPGPA in temperature-responsive white-light illumination was also successfully demonstrated. The molecular packing and temperature-dependent modulation of the aurophilic interactions were subtly taken as a functional relationship of the experimental correlation with emission wavelength and intensity. It is anticipated that the present results will provide new insights into aurophilic interactions and provide a molecular design strategy for the construction of intelligent and stimuli-responsive gold(I) complex-based luminescent materials.

Stable organic radicals are promising materials for information storage, molecular magnetism, electronic devices, and biological probes. Many organic radicals have been prepared, but most are non- or weakly emissive and degrade easily upon photoexcitation. It remains challenging to produce stable and efficient luminescent radicals because of the absence of general guidelines for their synthesis. Herein, we present a photoactivation approach to generate a stable luminescent radical from tris(4-chlorophenyl)phosphine (TCPP) with red emission in the crystal state. The mechanistic study suggests that the molecular symmetry breaking in the crystal causes changes of molecular conformation, redox properties, and molecular packing that facilitates radical generation and stabilization. This design strategy demonstrates a straightforward approach to develop stable organic luminescent radicals that will open new doors to photoinduced luminescent radical materials.

Materials showing metallophilic interactions continue to attract considerable theoretical and experimental attention largely because of their unusual and unanticipated photophysical behavior as well as their unique stimuli-responsive behavior in an aggregate or solid state. Metallophilic interactions are mostly found between metals with either identical (d10–d10) or different (s2–d8, d8–d10) configurations. Among various metallophilic interactions, aurophilic interactions (Au⋯Au) are well-known and widely reported. In this study, a new phosphorescent gold(I) complex, [(CF3Ph)3PAuC≡CPh] (TPPGPA) was reported. The crystal structure of TPPGPA demonstrated the formation of trimers caused by intermolecular aurophilic interactions. These trimeric crystals showed an efficient and nearly pure white-light emission with Commission Internationale de L’Eclairage 1931 chromaticity coordinates of (0.33, 0.34) at ambient conditions. Moreover, TPPGPA displayed fascinating mechanochromic and thermochromic luminescence properties in the crystalline state. The application of TPPGPA in temperature-responsive white-light illumination was also successfully demonstrated. The molecular packing and temperature-dependent modulation of the aurophilic interactions were subtly taken as a functional relationship of the experimental correlation with emission wavelength and intensity. It is anticipated that the present results will provide new insights into aurophilic interactions and provide a molecular design strategy for the construction of intelligent and stimuli-responsive gold(I) complex-based luminescent materials.

The exploration of artificial luminogens with bright emission has been fully developed with the advancement of synthetic chemistry. However, many of them face problems like weakened emission in the aggregated state as well as poor renewability and sustainability. Therefore, the development of renewable and sustainable luminogens with anti-quenching function in the solid state, as well as to unveil the key factors that influence their luminescence behavior become highly significant. Herein, a new class of natural rosin-derived luminogens with aggregation-induced emission property (AIEgens) have been facilely obtained with good biocompatibility and targeted organelle imaging capability as well as photochromic behavior in the solid state. Mechanistic study indicates that the introduction of the alicyclic moiety helps suppress the excited-state molecular motion to enhance the solid-state emission. The current work fundamentally elucidates the role of alicyclic moiety in luminogen design and practically demonstrates a new source to large-scalely obtain biocompatible AIEgens.

Stable organic radicals are promising materials for information storage, molecular magnetism, electronic devices, and biological probes. Many organic radicals have been prepared, but most are non- or weakly emissive and degrade easily upon photoexcitation. It remains challenging to produce stable and efficient luminescent radicals because of the absence of general guidelines for their synthesis. Herein, we present a photoactivation approach to generate a stable luminescent radical from tris(4-chlorophenyl)phosphine (TCPP) with red emission in the crystal state. The mechanistic study suggests that the molecular symmetry breaking in the crystal causes changes of molecular conformation, redox properties, and molecular packing that facilitates radical generation and stabilization. This design strategy demonstrates a straightforward approach to develop stable organic luminescent radicals that will open new doors to photoinduced luminescent radical materials.