Synthesis, crystal structure and iodine capture of Zr-based metal-organic polyhedron

Abstract A new zirconium-based metal-organic polyhedron (Zr-MOP-1) was successfully synthesized from Bis(cyclopentadienyl)zirconium dichloride and 2,5-pyridinedicarboxylic acid under solvothermal condition. It was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Four trinuclear zirconocene building blocks as well as six linear carboxylate ligands give rise to its tetrahedral configuration. Interestingly, Zr-MOP-1 possesses considerable reversible iodine sorption performance in organic phase featuring an optimal adsorption capacity of 283 mg g-1. The related kinetics absorption and desorption process were fully explored in detail by multiple complementary experiments and the adsorbed iodine species (I- and I3-) in Zr-MOP-1 had been further identified through crystallographic analyses. This work provides new possibilities for developing new and functional zirconium-based molecular cages materials.