Fig. 3. Comparison of benchtop (1 T) 1H NMR spectra acquired without (top) and with (bottom) SABRE hyperpolarization for 52 mM 4-methylpyridine and 5.2 mM catalyst in (A) methanol-d4 and (B) protonated methanol. SABRE enhancement factors and polarization levels as a function of substrate concentration in (C) methanol-d4 and (D) protonated methanol. The pre-catalyst concentration (5.2 mM) was kept constant in all cases. Enhancement factors and polarization levels are reported for the three distinct 1H resonances of the substrate: ortho (gray), meta (green) and methyl (blue). Error bars represent the standard deviation across 5 measurements.
