Synthesis And Fluorescent Properties Of Ln-MOFs And BTD-based MOFs

In the past decades, metal organic frameworks（MOFs） materials, due to its flexible structure, made them ideal candidates for gas storage and separation, heterogeneous catalysis, chemical sensing, biological imaging and other aspects. Among the study, the luminescence properties and its application for the MOFs also won attentions. Luminescent metal organic frameworks（LMOFs） materials have been widely used in the sensory system, and their permanent porosity often serves as a powerful platform for the reversible adsorption and release of these molecules.In this paper, firstly, several new isostructural lanthanide Metal-Organic Frameworks {[Ln3（L）4（OH）（H₂O）2]·DMAC}n（Ln = Tb（1）, Gd（2）, Eu（3）, Gd0.81Tb0.10Eu0.09（4） and Gd0.75Tb0.18Eu0.07（5）） were designed and prepared. Excitingly, samples 1, 3, 4 and 5 showed a reversibly Al3+-induced chromaticity switching as well as the reversibly Fe3+-induced emission switching. For the dual-doped isostructural MOF 4（Gd0.81Tb0.10Eu0.09L） and 5（Gd0.75Tb0.18Eu0.07L）, the CIE chromaticity coordinates of Al3+-4（0.3218, 0.2789） and Al3+-5（0.2742, 0.2821） were close to the standard white light（0.333, 0.333）.Secondly, 4,7-dibromo-2,1,3-benzothiadiazole was used as substrate to design and synthesis two ligands: 2,1,3-benzothiadiazole-4,7-dicarboxylic acid（H₂BTDC） and 4,4′-（benzothiadiazole-4,7-diyl）dibenzoate（H₂BTDB）. By employing 2,1,3-benzothiadiazole-4,7-dicarboxylic acid（H₂BTDC）, three novel coordination polymers 6-8 have been successfully obtained. The fluorescent properties of ligands and complexes 6 and 7 were discussed.