Macrocyclic compound

Patent Pending A macrocycle is, as defined by IUPAC, "a cyclic macromolecule or a macromolecular cyclic portion of a molecule."[1] In the chemical literature, organic chemists may consider any molecule containing a ring of nine or more atoms to be a macrocycle.[citation needed] In general, coordination chemists define a macrocycle more narrowly as a cyclic molecule with three or more potential donor atoms that can coordinate to a metal center. A well-known example is the group of drugs known as macrolides.