Dy-DTPA as supersensitive shifting and relaxational probe for NMR/MRI control of local temperature

摘要

The article develops an approach in which paramagnetic lanthanide complexes are considered and studied as NMR / MRI relaxational and shifting probes for determining local temperature and prospective diagnostics. A detailed NMR study of the paramagnetic properties of Na-2[Dy(DTPA)(H2O)] (I) complex is an example of the application of this approach. The substantial temperature dependence of the transverse relaxation on the ligand nuclei at high magnetic fields is due to the Curie spin contribution to the paramagnetic relaxation rate enhancement. A significant temperature dependence of relaxivity r(2) was experimentally detected. The activation free energy of the racemization Delta G(not equal)(298) in I is found to be 50 kJ mol(-1). The coordination compound I can also serve as the most sensitive H-1 NMR relaxational and shifting lanthanide paramagnetic probe for in situ temperature control in liquid medium. (C) 2020 Published by Elsevier Ltd.