Metal–organic frameworks (MOFs) are a class of porous polymers consisting of metalclusters (also known as Secondary Building Units - SBUs) coordinated to organicligands to form one-, two- or three-dimensional structures. The organic ligands included are sometimes referred to as "struts" or "linkers", one example being 1,4-benzenedicarboxylic acid (H2bdc).

MOFs are classified as reticular materials.