Fig. 3. Simulated polarization buildup curves (dashed lines) for the experiment shown in Fig. 2, taking into account the cumulative contribution of all spin pairs whose internuclear distance lies below a cutoff distance increased from 4 Å to 20 Å. The y-axis corresponds to the absolute transferred polarization, and no scaling has been applied to the simulated curves. Experimental points (black points) are identical to those given in Fig. 2c, including normalization with respect to the CO polarization.