A new stable luminescent Cd() metal-organic framework with fluorescent sensing and selective dye adsorption properties

A new luminescent metal-organic framework, {[Cd 3 (HL) 2 (H 2 O) 3 ]·3H 2 O·2CH 3 CN} n ( 1 ) (H 4 L = 1-(3,5-dicarboxylatobenzyl)-3,5-pyrazole dicarboxylic acid), has been synthesized by solvothermal reaction and characterized by infrared spectroscopy, powder X-ray diffraction, thermogravimetry measurements and so on. 1 shows a new trinodal (4,4,6)-connected topology. Importantly, 1 displays intense luminescence in the solid state and high luminescent sensitivity and selectivity for Fe 3+ , CrO 4 2− and Cr 2 O 7 2− ions in aqueous solution, making it a potential probe for detecting these substances. The quenching mechanisms are also further discussed in detail. In addition, further research on the adsorption of dyes shows that 1 can selectively adsorb Congo red dye from other dye molecules. A stable Cd-MOF with free carboxyl groups in the channels has been synthesized, showing luminescent sensitivity for Fe 3+ , CrO 4 2− and Cr 2 O 7 2− ions in aqueous solution, and selective adsorption of Congo red dye.