The design and characterization of purely organic room‐temperature phosphorescent (RTP) materials for optoelectronic applications is currently the focus of research in the field of organic electronics. Particularly, with the merits of preparation controllability and modulation flexibility, host–guest material systems are encouraging candidates that can prepare high‐performance RTP materials. By regulating the interaction between host and guest molecules, it can effectively control the quantum efficiency, luminescent lifetime, and color of host–guest RTP materials, and even produce RTP emission with stimuli‐responsive features, holding tremendous potential in diverse applications such as encryption and anti‐counterfeiting, organic light‐emitting diodes, sensing, optical recording, etc. Here a roundup of rapid achievement in construction strategies, molecule systems, and diversity of applications of host–guest material systems is outlined. Intrinsic correlations between the molecular properties and a survey of recent significant advances in the development of host–guest RTP materials divided into three systems including rigid matrix, exciplex, and sensitization are presented. Providing an insightful understanding of host–guest RTP materials and offering a promising platform for high throughput screening of RTP systems with inherent advantages of simple material preparation, low‐cost, versatile resource, and controllably modulated properties for a wide range of applications is intended.

Developing full-color organic ultralong room temperature phosphorescence (OURTP) materials with continuously variable afterglow emission is of considerable practical importance in diverse optoelectronic applications but remains a formidable challenge. Here, we present an effective strategy for on-demand engineering of afterglow color in water-soluble polymeric systems via efficient phosphorescence Förster resonance energy transfer. Using a blue afterglow emitting water-soluble polymer as host and a series of fluorescent emitters with varied emissive colors as guests, afterglow emission is rationally modulated, conferring the full-color afterglow emission ranging from blue to red and even white with ultralong lifetimes up to 4.2 s and photoluminescence quantum yields of 36%.These water-soluble multicolor-emitting polymeric afterglow systems can function as OURTP security inks, and multilevel information encryption was successfully established by RGB-based multicolor security printing. These results present important guidance in developing high-performance afterglow polymers with on-demand color tuning ability for remarkable optoelectronic applications.

Oxidative α-cyanation of tertiary amines is catalyzed by gold complexes with trimethylsilyl cyanide to afford the corresponding α-aminonitriles in the presence of tert-butyl hydroperoxide in good to excellent yields under acid-free conditions at room temperature.

Through the fluorine-induced aggregate-interlocking (FIAI) strategy, the designed afterglow materials showed both improved quantum yields and prolonged lifetimes by breaking through the intrinsic bottlenecks of organic afterglow.