Two Zirconium Metal–Organic Cages with S4 and D2d Symmetry: Construction and Detection of Antibiotics

The construction of robust zirconium metal–organic cages (Zr-MOCs) with specific geometric structures and properties is of great significance but is challenging. Herein, two Zr-MOCs (Zr-MOC-1 and Zr-MOC-2), which respectively comprise triphenylamine and carbazole functional groups, are synthesized and structurally characterized. Compared with the perfect tetrahedral geometry with S4 symmetry in Zr-MOC-1, the presence of carbazole structural units leads the tetrahedral structure of Zr-MOC-2 to be distorted, and then assumes it a trigonal pyramid geometry with D2d symmetry. Furthermore, these two Zr-MOCs could be used as soluble chemical sensors for probing nitrofuran antibiotics, and the detection sensitivity of Zr-MOC-2 is higher than that of Zr-MOC-1. These results demonstrate that the introduction of appropriate structural units into Zr-MOCs may significantly impact their architectures and properties.