Cyclam, is a metal complex of azamacrocycles which is often more stable in vitro alternatives to open chain ligands. Cyclam (1,4,8,11-tetraazacyclotetradecane) is an organic compound with the formula (NHCH2CH2NHCH2CH2CH2)2. It is a white solid that is soluble in water. The compound is notable as a macrocyclic ligand, which binds strongly to many transition metal cations.