On the relationship between NMR chemical shifts of thermally polarized and hyperpolarized 89Y complexes and their solution structures

摘要

Recently developed dynamic nuclear polarization (DNP) technology offers the potential of increasing the NMR sensitivity of even rare nuclei for biological imaging applications. Hyperpolarized ⁸⁹Y is an ideal candidate because of its narrow NMR linewidth, favorable spin quantum number (I=½) and long longitudinal relaxation times (T1). Strong NMR signals were detected in hyperpolarized ⁸⁹Y samples of a variety of yttrium complexes. A dataset of ⁸⁹Y NMR data composed of 23 complexes with polyaminocarboxylate ligands was obtained using hyperpolarized ⁸⁹Y measurements or ¹H,⁸⁹Y-HMQC spectroscopy. These data were used to derive an empirical equation that describes the correlation between the ⁸⁹Y chemical shift and the chemical structure of the complexes. This empirical correlation serves as a guide for the design of ⁸⁹Y sensors. Relativistic (DKH2) DFT calculations were found to predict the experimental ⁸⁹Y chemical shifts to a rather good accuracy.