Synthesis, Crystal Structures And Properties Of Metal-Organic Frameworks Based On Cyclotriphosphazene-Functionalized Carboxylate Ligands

Cyclotriphosphazene and their derivatives are an important class of molecules which are widely applied in supramolecular chemistry and material chemistry; however MOF chemistry regarding cyclotriphosphazene and their derivatives remained less explored. As shown in the text, we designed and synthesized three novel cyclotriphosphazene-functionalized multicarboxylate ligands: hexakis(3,5-dicarboxylatephenyloxy)cyclotriphosphazene (H12L), hexakis(4-carboxylatephenoxy) cyclotriphosphazene (H6L1) and hexakis(3-carboxylatephenoxy) cyclotriphosphazene(H6L2), and used them to construct twelve metal-organic frameworks via solvothermal reactions with transition metal ions, alkaline-earth metal ions and rare-earth metal ions, respectively. Their formulae are shown as following:[Cu3L(H2O)3]·5DMA-4EtOH·2H2O (L=L1) (1)[Cu3L(H2O)3]·5DMF-2MeOH·2H2O (L=L2) (2)[Cd5L(H2O)4]·2(CH3)2NH2·6DMF (L=L3) (3)[Mg3L2(H2O)6]·6(Me2NH2)·DMA-H2O (L=L1) (4)[Ca3L(DMF)2](L=L1)(5)[Ba3L(H2O)4(DMF)]·DMF·2H2O (L=L1) (6)[Sm4L2(CH3COO)(H2O)]·(CH3)2NH2·17DMA (L=L1) (7)[Eu4L2(CH3COO)(H2O)]·(CH3)2NH2·17DMA (L= L1) (8)[Gd4L2(CH3COO)(H2O)]·(CH3)2NH2·13DMA (L=L1) (9)[Tb4L2(CH3COO)(H2O)]·(CH3)2NH2·15DMA (L= L1) (10)[Dy4L2(CH3COO)(H2O)]·(CH3)2NH2·17DMA (L=L1) (11)[Ho4L2(CH3COO)(H2O)]·(CH3)2NH2·20DMA (L= L1) (12)Single-crystal X-ray structure analysis and basic characterization were carried out on these MOFs, and the fluorescence properties and adsorption separation performance were investigated for some of them.