Highly Tunable MOF Luminophores Featuring Anthracene Directed Assembly and Fluorescence Regulation.

Metal-organic frameworks (MOFs) have been recognized as a potential platform for the development of tunable luminophores owing to their highly modulable structures and components. Herein, two MOF luminophores based on Cd(II) ions, 1,3,5-tri(4-pyridinyl)benzene (TPB), and 1,4-dicarboxybenzene (H ₂ BDC) were constructed. The directed assembly of the metal ions and organic linkers results in [Cd ₂ (BDC) ₂ (TPB)(H ₂ O)]· x (solvent) ( MOF-1 ) featuring TPB-based blue fluorescence centered at 425 nm. By introducing anthracene as the structure directing agent (SDA) for assembly regulation, [Cd ₂ (BDC)(TPB) ₂ (NO ₃ ) ₂ ]· x (solvent) ( MOF-2 ) was obtained, which reveals anthracene feeding-dependent high tunable emission in the 517-650 nm range. Detailed components, photophysical properties, and structural characteristics investigations of MOF-2 indicate the TPB and NO ₃ ^- interactions as the origin of its redshifted emission compared with that of MOF-1 . Furthermore, the fluorescence of MOF-2 was found to be regulatable by the anthracene feeding based on the SDA-determined crystallinity of the crystalline sample. All these results provided a unique example of the structural and fluorescence regulation of MOF luminophores.