“…The field of MRI contrast agents has been dominated by trivalent gadolinium (Gd 3+ ) complexes [5][6][7][8] as they are paramagnetic with seven unpaired electrons [5]. However, concerns regarding Gd 3+ toxicity [9][10][11] are directing research towards the use of other metals as paramagnetic contrast agents. This resulted in an expansion of non-lanthanide based contrast agents (e.g.…”