Aggregation in Amphiphilic Macrocycle-Substituted Gd³⁺ DOTA-Type Chelates Is Affected by the Regiochemistry of Substitution

Gd³⁺ chelates of macrocyclic bifunctional chelators (BFCs) can differentiate into two regioisomers: corner and side. These isomers afford different orientations of chelate relative to conjugate. These differences alter the self-assembly, tumbling, and effectiveness as magnetic resonance imaging contrast agents of the two biphenyl conjugate isomers