Gd(III) complex has one coordinated water molecule and shows
better relaxometric properties than the complexes of ligands based
on the DOTA or DTPA skeleton.60
Structures with DOTA-like ligands
The prototype dota4− anion is coordinated to a lanthanide(III)
ion by four ring nitrogen atoms and four carboxylate groups in a well-known fashion. The nitrogen atoms as well as oxygen atoms
form N4 and O4 bases, which are planar and parallel to each other.
The O4 plane is capped with a coordinated water molecule. The
ethylene groups of the macrocycle adopt a gauche conformation
forming a five-membered coordination metallacycle with either d
or k configuration. This results in two possible square [3,3,3,3]
conformations of the macrocycle, dddd and kkkk. The pendant
acetate arms may occupy two orientations, D or K. Therefore, in