Supramolecular Organic Frameworks with Controllable Shape and Aggregation-Induced Emission for Tunable Luminescent Materials through Aqueous Host-Guest Complexation

Here, a series of shape-controllable and fluorescent supramolecular organic frameworks (SOFs) exhibiting aggregation-induced emission (AIE) are reported as a new kind of tunable luminescent material, constructed hierarchically from fluorescent guests (1-5) and cucurbit[8]uril (CB[8]) through homo/hetero host-guest complexation in water. These SOFs can further form regular supramolecular cuboids via a hierarchical assembly process in the solid state. Interestingly, the emission of hetero-SOFs systems exhibiting AIE, which are a combination of two or three SOFs with two complementary colors (i.e., yellow and blue) or three primary RGB colors (red, green, and blue) through the hetero host-guest complexation between CB[8] and two pyridinium rings of different guests, can be easily tuned by adjusting the excitation wavelength and guests ratios, thereby achieving a wide-color tunability (approximate to 64% sRGB area) and white-light emission (0.31, 0.34) in the solution state. This study therefore provides insight into the fabrication of tunable luminescent materials based on SOFs with controllable shapes and AIE properties as fluorescent platforms, and may facilitate the further design and synthesis of tunable luminescent materials and other fluorescent supramolecular systems based on host-guest complexation both in the solution and solid states.