Structure, Design and Synthesis

Abstract

Flexible metal–organic frameworks (MOFs) form an attractive class of solid-state materials that exhibit structural softness and a discernible response to external stimulus, physical or chemical. These features make them suitable for several applications for energy, environment and biomedicine, with the ability to tune their characteristics at the molecular level. This chapter provides a detailed analysis of their synthesis and structural properties, with the aim to derive design principles. The flexibility is stated at two levels: one part with the focus on the building blocks of such systems, and the other considering the topological viewpoint in their supramolecular assemblies. The role of metals, ligands and guest molecules in influencing their dynamic nature is discussed with several examples from a range of MOFs. The chapter closes with a perspective on the factors that can enable complete understanding of flexibility in MOFs and thereby lead to a greater understanding in terms of designing such materials.