Figure 3.

a) Schematic depicting SABRE catalyst activation and parahydrogen / substrate exchange on the Ir hexacoordinate complex, resulting in nicotinamide-¹⁵N hyperpolarization. b) ¹⁵N NMR spectrum recorded in situ in a 7 T NMR spectrometer during parahydrogen bubbling through methanol-d₄ solution containing activated 10 mM Ir hexacoordinate catalyst and 100 mM ¹⁵N-enriched nicotinamide. The signal enhancement for hyperpolarized bounded nicotinamide was about 100. The spectrum is recorded with 32 acquisitions, with 1 s repetition time between successive scans (total acquisition time: 32 s).