Metal–organic frameworks (MOFs) are a class of compounds consisting of
metal clusters (also known as SBUs) coordinated to organic ligands 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 (BDC).
More formally, a metal–organic framework is a potentially porous extended
structure made from metal ions and organic linkers. An extended structure is a
structure whose sub-units occur in a constant ratio and are arranged in a
repeating pattern.