An Interdigitated Metalloporphyrin Framework: Two-Dimensional Tessellation, Framework Flexibility, and Selective Guest Accommodation

Abstract

A novel porphyrin-based metal−organic framework (MPF-3) was synthesized by the solvothermal reaction of Zn(NO3)2·6H2O and meso-tetra(3-pyridyl)porphine in N,N-dimethylformamide (DMF). Its structure was characterized by single crystal X-ray diffraction and found to be a two-dimensional (2D) interdigitated framework in which DMF solvent molecules reside between the interdigitated layers. The observed 2D topology can be related to the Cairo pentagonal tessellation. X-ray powder diffraction reveals that MPF-3 undergoes a phase transformation when the solvent molecules are removed by heating. Surprisingly, the original topologies are restored when the desolvated phase is immersed in DMF, thereby demonstrating the flexibility of the framework.