Accueil > Publications > Recherche par années > Années 1990 > 1998

Toth, E ; Helm, L ; Merbach, AE ; Hedinger, R ; Hegetschweiler, K ; Janossy, A

Structure and dynamics of a trinuclear gadolinium(III) complex : The effect of intramolecular electron spin relaxation on its proton relaxivity

Inorganic Chemistry 37 (16) 4104-4113

par Administrateur - publié le

Abstract :

The trinuclear [Gd-3(H(-3)taci)(2)(H2O)(6)](3+) complex has been characterized in aqueous solution as a model compound from the point of view of MRI : the parameters that affect proton relaxivity have been determined in a combined variable temperature, pressure, and multiple-field O-17 NMR, EPR,and NMRD study. The solution structure of the complex was found to be the same as in solid state : the total coordination number of the lanthanide(IB) ion is 8 with two inner-sphere water molecules. EPR measurements proved a strong intramolecular dipole-dipole interaction between Gd(III) electron spins. This mechanism dominates electron spin relaxation at high magnetic fields (B > 5 T).