Hadjiali, Sara, Marvin Bergmann, Alexey Kiryutin, Stephan Knecht, Grit Sauer, Markus Plaumann, Hans-Heinrich Limbach, Herbert Plenio, and Gerd Buntkowsky. “The Application of Novel Ir-NHC Polarization Transfer Complexes by SABRE.” The Journal of Chemical Physics 151, no. 24 (December 28, 2019): 244201.
https://doi.org/10.1063/1.5128091.
In recent years, the hyperpolarization method Signal Amplification By Reversible Exchange (SABRE) has developed into a powerful technique to enhance Nuclear Magnetic Resonance (NMR) signals of organic substrates in solution (mostly via binding to the nitrogen lone pair of N-heterocyclic compounds) by several orders of magnitude. In order to establish the application and development of SABRE as a hyperpolarization method for medical imaging, the separation of the Ir-N-Heterocyclic Carbene (Ir-NHC) complex, which facilitates the hyperpolarization of the substrates in solution, is indispensable. Here, we report for the first time the use of novel Ir-NHC complexes with a polymer unit substitution in the backbone of N-Heterocyclic Carbenes (NHC) for SABRE hyperpolarization, which permits the removal of the complexes from solution after the hyperpolarization of a target substrate has been generated.