A Microporous Anionic Metal- Organic Framework for Sensing Luminescence of Lanthanide( III) Ions and Selective Absorption of Dyes by Ionic Exchange

Herein, a novel anionic framework with primitive centered cubic (pcu) topology, [(CH3)(2)NH2](4)[(Zn(4)dttz(6))Zn-3]15DMF4.5H(2)O, (IFMC-2; H(3)dttz=4,5-di(1H-tetrazol-5-yl)-2H-1,2,3-triazole) was solvothermally isolated. A new example of a tetranuclear zinc cluster {Zn(4)dttz(6)} served as a secondary building unit in IFMC-2. Furthermore, the metal cluster was connected by Zn-II ions to give rise to a 3D open microporous structure. The lanthanide(III)-loaded metal-organic framework (MOF) materials Ln(3+)@IFMC-2, were successfully prepared by using ion-exchange experiments owing to the anionic framework of IFMC-2. Moreover, the emission spectra of the as-prepared Ln(3+)@IFMC-2 were investigated, and the results suggested that IFMC-2 could be utilized as a potential luminescent probe toward different Ln(3+) ions. Additionally, the absorption ability of IFMC-2 toward ionic dyes was also performed. Cationic dyes can be absorbed, but not neutral and anionic dyes, thus indicating that IFMC-2 exhibits selective absorption toward cationic dyes. Furthermore, the cationic dyes can be gradually released in the presence of NaCl.