Figure 2.

NMR pulse sequences for heteronuclear spin order transfer. a) The asymmetric J‐connectivity in the para‐hydrogenated sidearm is exploited to transfer spin order from the added para‐H₂ to the labeled carbons ¹³C₃ and ¹³C₄. The nuclei that compose the spin system of interest are highlighted in red. b) Pulse sequences for spin‐order transfer to ¹³C magnetization: b₁) polarization of ¹³C₃ and b2) polarization of ¹³C₄. The thin and large rectangles represent 90° and 180° pulses, and the subscripts indicate the phases. The black filled rectangle in the sequence block (b₁) represent a selective pulse on ¹³C₃. The vertical dashed lines separate the logical blocks of the pulse sequence. The circled numbers highlight specific time points used to follow the evolution of the spin density operator through the sequence as reported in the list beside the drawing. The dashed 90° pulse after timepoint 9 is used to convert S _4y into S _4z for magnetization storage before the cleavage step.