Metal–Organic Frameworks: Examples, Counterexamples, and an Actionable Definition

It is not unusual for advances in science to run ahead of nomenclature for the discovered phenomena. However, in the case of metal–organic frameworks (MOFs), research activity has been booming for more than a decade, and yet there is no agreed upon definition for the term. Different structural aspects of these materials are critically analyzed with examples and counterexamples to arrive at a definition of MOF that is both definite and consistent with common usage.