Abstract

Strong, directional interactions between building blocks have been prerequisites for the assembly of permanently porous frameworks. For instance, permanent porosity is realized in metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), and hydrogen-bonded organic frameworks (HOFs) by the rigid, directional natures of coordination, covalent, and hydrogen bonds, respectively. Conversely, van der Waals (vdW) interaction or dispersion interaction, a ubiquitous attraction interaction among molecules, has been barely used for the construction of permanently porous frameworks because of its weak interaction energy and the lack of directionality. In this study, we demonstrate that vdW interaction drives the assembly of three-dimensional open frameworks from supramolecular building blocks, so-called metal-organic polyhedra (MOPs), a group of cage-shaped metal complexes with high structural modularity like MOFs. Particularly, we designed octahedral MOPs and were assembled into diamond networks (Figure). The resulting porous solids assembled via vdW showed high chemical stability, high thermal stability over 300 ºC and high surface area (one is over 2,000 m2/g). By taking advantage of reversible vdW interaction, the porous solids can be dissolved in solvents as MOPs and recrystallized to be open framework structures. This discovery highlights an overlooked potential of weak, less directional vdW interactions toward the design of porous framework materials.

Biography

Prof. Shuhei Furukawa received his PhD in 2005 from Kyoto University. After postdoctoral research in the group of Prof. Steven De Feyter and Prof. Frans De Schryver at Katholieke Universiteit Leuven, Belgium, he returned to Kyoto University in 2007 as an Assistant Professor. In 2008, he moved to the JST ERATO Kitagawa Integrated Pores Project as a Group Leader and since 2010 he has been working at the Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University (2010-2020 Associate Professor, 2020- Full Professor). His main research interest is in coordination chemistry across multiple length scales, including synthesis and property of porous materials and their applications in cell biology, sensors and environmental science.