Benefits and complexity of defects in metal-organic frameworks

Defect engineering has developed over the last decade to become an inimitable tool with which to shape Metal-Organic Framework (MOF) chemistry; part of an evolution in the perception of MOFs from perfect, rigid matrices to dynamic materials whose chemistry is shaped as much by imperfections as it is by their molecular components. However, challenges in defect characterisation and reproducibility persist and, coupled with an as-yet opaque role for synthetic parameters in defect formation, deny chemists the full potential of reticular synthesis. Herein we map the broad implications defects have on MOF properties, highlight key challenges and explore the remarkable ways imperfection enriches MOF chemistry. Engineering defects into metal-organic frameworks is a strategy to grant additional properties but there are still challenges with their reproducibility. Here, this Perspective presents the benefits of defects in metal-organic framework properties and key challenges in the field.