Hyperpolarization of [13C]formate using parahydrogen

Abstract

Sodium [13C]formate was successfully hyperpolarized using parahydrogen-induced polarization by means of side-arm hydrogenation (PHIP-SAH). Allyl [13C]formate was hyperpolarized using homogeneous hydrogenation of the corresponding unsaturated precursor (propargyl [13C]formate) in acetone-d6 with parahydrogen. The observed proton polarization was estimated as 16.6 ± 0.6 % while achieving 80 % chemical conversion. The 1H-to-13C polarization transfer was performed using magnetic field cycling. The highest observed polarization for 13C nuclei was estimated as 1.7 ± 0.2 % and was obtained at 250 nT polarization transfer magnetic field. We demonstrate that the 13C hyperpolarization is retained during the hydrolysis of allyl [13C]formate and hyperpolarized sodium [13C]formate was produced with P13C of 0.4 ± 0.1 %.

Keywords

• hyperpolarization · parahydrogen · PHIP-SAH · formate