Fig. 1.

Chemical (left) and crystallographic structures from diffraction of Gd^III-containing complexes 1 (center) and 2 (right). Thermal ellipsoids are drawn at 50% probability. Counterions, outer-sphere water molecules, and hydrogen atoms are not shown for clarity. Grey = carbon; blue = nitrogen; red = oxygen; green = fluorine; and sea green = gadolinium. Crystallographic data for the structures has been deposited at the Cambridge Crystallographic Data Centre under deposition numbers CCDC 1991782 and 1991783.