Fig. 1.
Structures of (a) diethylenetriaminepentaacetic acid (DTPA) and (b) 1,4,7,10-tetraazacyclododecane tetraacetic acid (DOTA); (c) (d) Examples of q = 2 DTPA based complexes (q: number of bound water molecules). The increase in q is made possible by removing one carboxylate arm of the parent DTPA.83,84
