Shape–Tunable and Luminescence Cascade–Enhanced 2d Supramolecular Organic Framework

Abstract

Owing to their specific properties including good flexibility, lightweight, high adaptability and adjustable structure, two–dimensional (2D) nano–materials have attracted much attention in recent years. Herein, an unprecedented, shape–controllable two–dimensional and fluorescent supramolecular organic framework (CE–SOF) that exhibiting assembly–induced emission enhancement, was reported through dynamic self–assembly and self–sorting from coumarin–modified dibenzo–24–crown–8 derivative (G) and cucurbit[8]uril (CB[8]) with crown ether as the guest in water. Without any tedious chemical modification, we have succeeded in tuning the topological morphologies of free G from nanoparticles to nano–sheets, octahedron–liked 3D nanostructures, with the addition of CB[8] and dodecyl–modified sulfonatocalix[4]arene (SC4AD), in sequence. Significantly, the first–order and cascaded assembly result in 3.3 and 56.1 times increase in fluorescence intensity, along with red shifts from 436 nm to 545, 530 nm, respectively. When energy acceptor pyridine cautions modified diarylethene derivative (DAE) was introduced, photo–controlled energy transfer in water could be realized with luminescent color transferred from green to no light, enabling the potential application in multicolor anti–counterfeiting by the altered light of UV/NIR. Besides, these assemblies also presented good applications in cells imaging and antibiotics detection.

Keywords: Supramolecular organic frameworks (SOFs), Two-dimensional (2D) nanomaterials, Cucurbit[8]uril, Multicolor luminescence, Controlled morphology