Dimension-Controllable and Photo-Responsive Supramolecular Organic Framworks through Cucurbit8uril-based Self-Assembly

Dimension-controllable supramolecular organic frameworks (SOFs) with aggregation-enhanced fluorescence are hierarchically fabricated through the host-guest interactions of cucurbit8uril (CB8) and coumarin-modified tetraphenylethylene derivatives (TPEC). The three-dimensional layered SOFs could be constructed from the further stacking of two-dimensional mono-layered structures via simply regulating the self-assembly conditions including the culturing time and concentration. Upon light irradiation under the wavelength of 365 nm, the photodimerization of coumarin moieties occurred, which resulted in the transformation of the resultant TPEC _n /CB8 _4n two-dimensional SOFs into robust covalently-connected 2D polymers with molecular thickness. Interestingly, the supramolecular system of TPEC _n /CB8 _4n exhibited intriguing multicolor fluorescence emission from yellow to blue in the time range of 0 - 24 h at 365 nm irradiation, possessing potential applicability for photochromic fluorescence ink.