Solvothermal syntheses and properties of europium metal organic framework with 1, 3-bis(carboxymethyl)imidazolium chloride ionic liquid

A new lanthanide metal organic framework, namely [Eu(C7H7O4N2)(H2O)2(Cl0.38)2]Cl1.24 (1), was solvothermally synthesized using 1,3-bis(carboxymethyl)imidazolium chloride ([H2imdc]Cl) ionic liquid as a ligand. This compound was structurally characterized by single crystal X-ray diffraction and its properties were analyzed spectroscopy and theoretical studies. In 1, Eu (III) ions have only one coordination environment, and the ligands exhibit one coordination mode. The Eu3+ ions and ligands are connected to construct wavelike 2D cationic layers through coordination bonds, and then the 2D networks further interconnected through hydrogen bonds. The luminescent properties were studied at 77 K. The emission spectrum shows that there is one Eu3+ ion site in asymmetric unit, which is consistent with the results of the X-ray crystal structure analysis. Compound 1 exhibits characteristic emission bands of Eu3+ with emission lifetime of 0.336 ms.