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Dynamic emissive materials in aqueous media have received much attention owing to their ease of preparation, tunable luminescence and environmental friendliness. However, hydrophobic fluorophores usually suffer from aggregation-caused quenching in water. In this work, we constructed an artificial light-harvesting system by using a non-covalent aggregation-induced emission dimer as antenna and energy donor. The dimer is quadruple hydrogen bonded from a ureidopyrimidinone derivative ( M ) containing a tetraphenylethylene group. The dispersed nano-assemblies based on the dimer in aqueous media were fabricated with the help of surfactant. By loading a hydrophobic acceptor molecule DBT into the nano-assemblies, man-made light-harvesting nanoparticles were fabricated, showing considerable energy transfer efficiency and a relatively high antenna effect. Additionally, the fluorescence color of the system can be gradually tuned by varying the content of the acceptors. This study provides a general way for the construction of an aqueous light-harvesting system based on a supramolecular dimer, which is important for potential application in luminescent materials.

White-light emission in donor–acceptor systems usually requires relatively high acceptor content and/or multiple acceptors to "neutralize" the primary color of donors. Herein, a cyanostilbene-bridged ditopic ureidopyrimidinone donor (CSU) was designed and synthesized, which can self-assemble into dispersed nanoparticles in water. Fascinatingly, efficient white-light emission can be realized by co-assembling 0.1% DBT into the nanoparticles through a light-harvesting strategy. This new system is further demonstrated for use in white-light encryption materials. [ABSTRACT FROM AUTHOR]

Efficient energy transfer is ubiquitous in natural light-harvesting systems (LHSs), which has inspired humans to develop various carrier platforms and energy transfer strategies to mimic nature. In this study, we employ pillar [5]arene-mediated nanoparticles as the nano-platform and a sequential energy transfer strategy to achieve a highly efficient LHS. Specifically, by incorporating the hydrophobic dye, eosin Y (ESY) into the nanoparticles as a relay acceptor, the excitation energy from the host-guest donor WP5 ⸧ G can be efficiently transferred to the final acceptor, sulforhodamine 101 (SR101), making the overall donor energy transfer efficiency up to 94%. Under this condition, the radiative rate constant (k r) of WP5 ⸧ G is almost 8 times higher, and the emission brightness (ε (λ abs) × φ F) is nearly doubled, indicative of the rapid and efficient energy transfer process. Finally, the as-prepared LHS nanoparticles were applied to LED devices to achieve color-tunable photoluminescence. This work demonstrates a fabrication strategy for highly efficient light-harvesting systems that holds great potential for manufacturing bright organic luminescent materials. [Display omitted] • A two-step light-harvesting system was successfully constructed. • The system was completely self-assembled in water phase. • The overall energy transfer efficiency of the donor is up to 94%. • The emission brightness after energy transfer was doubled. • The nanoparticles can be used to make photoluminescent devices. [ABSTRACT FROM AUTHOR]