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Toth, E ; Helm, L ; Kellar, KE ; Merbach, AE

Gd(DTPA-bisamide)alkyl copolymers : A hint for the formation of MRI contrast agents with very high relaxivity

Chemistry-A European Journal 5 (4) 1202-1211

par Administrateur - publié le

Abstract :

A variable-temperature, multiple-field O-17 NMR and EPR spectroscopic study has been performed on three Gd(DTPA-bisamide)alkyl copolymers, [Gd(DTPA-BA)-(CH2)(n)](x) (n = 6, 10, 12 ; DTPA = diethylenetriamine-N,N,N’,N ",N’’’-pentaacetate). The rate and mechanism of water exchange is identical for the polymer complexes and [Gd(DTPA-BMA)(H2O)], which can be considered as the monomer unit of the polymers. Transverse electronic relaxation rates, measured by EPR, increase with increasing rotational correlation time. Rigid intramolecular micellelike structures form in aqueous solutions of the Gd(DTPA-bis-amide)alkyl copolymers.