Gadolinium complex of tris[(3-hydroxy-1-methyl- 2-oxo-1,2-didehydropyridine-4-carboxamido)ethyl]-amine: A New Class of gadolinium magnetic resonance relaxation agents

Approaching the Kinetic Inertness of Macrocyclic Gadolinium(III)‐Based MRI Contrast Agents with Highly Rigid Open‐Chain Derivatives

“…Raymond and co-workers. [20] Kinetic measurements: The rates of the metal exchange reactions involving the [Gd(cddadpa)]  complex and the Cu 2+ ion were studied by using UV-Vis spectrophotometry following the formation of the [Cu2(cddadpa)] complex. The conventional UV-vis spectroscopic method was applied to follow the decomplexation reactions of [Gd(cddadpa)]  as these reactions were very slow even at relatively low pH.…”

“…This is demonstrated by comparing the pGd values calculated as proposed by K. N. Raymond and co-workers (Table 1). [20] The , resulting from the integration of a highly rigid diaminocyclohexane unit in the ligand skeleton. The deceleration of the dissociation is a consequence of the strained structure of the chelate, as demetallation requires structural rearrangements that will proceed more slowly for complexes with non-flexible ligands.…”

High‐Relaxivity MRI Contrast Agents: Where Coordination Chemistry Meets Medical Imaging

“…Complex 12 demonstrates the importance of an intramolecular hydrogen-bonding network which preorganizes the ligand for metal complexation in the TREN-capped complexes such as 1. [44,60,61] The extension of the spacer in TRPN disrupts these interactions, resulting in a lower pGd. While most deviations from the TREN cap have resulted in significantly decreased stability, an exception is the TACN (triazacyclononane) scaffold (13) which attains a similar pGd = 18.7.…”

1,2-Hydroxypyridonates as Contrast Agents for Magnetic Resonance Imaging: TREN-1,2-HOPO

“…TREN-1,2-HOPO 15 and 3-benzoxy-4-carboxy-2-pyridone (3,2-HOPO(Bn) acid) 5 were synthesized as previously reported. 1 H and 13 C NMR spectra were obtained on Bruker AVQ-400 spectrometers and are reported in ppm.…”