Direct detection of 17O NMR in [Gd(DOTA)]- by NMR Spectroscopy

Abstract

The 17O NMR spectrum of the non-coordinated carboxyl oxygen in the Gd(III) DOTA complex has been observed experimentally. Its line width is essentially unaff ected by paramagnetic relaxation due to Gd, and due only to the quadrupole pathway. The results are supported by the relevant parameters (hyperfine and quadrupole coupling constant) calculated by relativistic DFT methods. This finding opens new avenues for investigating the structure and reactivity of paramagnetic Gd(III) complexes used as contrast agents in MRI.