White-Light Emission of a Binary Light-Harvesting Platform Based on an Amphiphilic Organic Cage

White-light emissive materials with stable photophysical properties are of great importance for their potential applications in information display, fluorescent sensors, and optical-recording systems. Herein, an amphiphilic tetraphenylpyrazine (TPP)-based cage compound (TPP-Cage) was facilely synthesized by reaction of propeller-like TPP with aggregation-induced emission characteristics and triglycol monomethyl ether-substituted triazine. By immobilizing the twisted conformation of TPP, TPP-Cage showed obvious helical chirality in the solution and aggregated state. TPP-Cage emits strong deep blue fluorescence in solution due to the restriction of intramolecular rotation of the TPP unit. Its amphiphilic nature enables it to serve as an excellent light harvesting platform to encapsulate diketopyrrolopyrrole (DPP) with aggregation-caused quenching effect in its hydrophobic cavity in aqueous medium, forming the DPP@TPP-Cage complex. Such inclusion prevents pi-pi stacking of DPP enabling it to emit strong yellow-light emission in the aggregated state. Due to the complementary emission colors of TPP-Cage and DPP, DPP@TPP-Cage exhibited stable white-light emission in the aggregated state and poly(ethylene glycol) film. This work not only introduces a promising strategy for development of chiral compounds through immobilization of propeller like achiral molecules but also provides a prospective pathway for white-light emission based on supramolecular assembly.