Europium-cadmium organic framework with zwitterionic ligand exhibiting tunable luminescence, CO2 adsorption and dye degradation

Porous lanthanide-transition heterometallic metal-organic frameworks (MOFs) as a subclass of porous hybrid materials have attracted considerable attention as a new advance in the research on MOFs. However, rationally designing and constructing heterometallic MOFs with desirable properties remains a challenging task. In this work, involving the heterometallic cooperative crystallization method, a novel europium-cadmium MOF based on a zwitterionic carboxylate ligand, [EuCd(pbbp) 2 (SO 4 ) 2 Cl 2 (H 2 O) 3 ] ( 1 ), (H 2 pbbp·2Cl ​= ​1,1'-(1,4-phenylene-bis(methylene))-bis(3-carboxy pyridinium) dichloride), has been solvothermally synthesized. Complex 1 was characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectroscopy, and thermogravimetric analysis. The structure of complex 1 consists of Eu–Cd heterometallic chains with one-dimensional channels. Complex 1 shows interesting excitation-dependent luminescence at room temperature. The gas adsorption studies show that complex 1 exhibits highly selective adsorption of CO 2 over N 2 and H 2 under ambient conditions, which may be caused by the stronger interaction of CO 2 with the positively charged pyridinium functional groups. In addition, the photocatalytic activity studies indicate that complex 1 shows good activity in rhodamine B dye degradation. A europium-cadmium MOF based on a zwitterionic carboxylate ligand has been solvothermally synthesized, which exhibits interesting excitation-dependent luminescence, highly adsorption of CO 2 under ambient conditions, and good photocatalytic activity in rhodamine B dye degradation. • A europium-cadmium heterometal-organic framework was prepared. • Complex 1 exhibit excitation-dependent luminescence at room temperature. • Complex 1 shows the good photocatalytic activity for degradation of rhodamine B. • Gas adsorption was applied to study the porosity.