DOTA

1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (also known as DOTA) is an organic compound with the formula (CH₂CH₂NCH₂CO₂H)₄. The molecule consists of a central 12-membered tetraaza (i.e., containing four nitrogen atoms) ring. DOTA is used as a complexing agent, especially for lanthanide ions. Its complexes have medical applications as contrast agents and cancer treatments.