Selective excitation doubles the transfer of parahydrogen-induced polarization to heteronuclei

In this work, we present a new pulse sequence to transform the spin order added to a molecule after the pairwise addition of parahydrogen into C-13 polarization. Using a selective 90 degrees preparation instead of a non-selective 45 degrees excitation, the new variant performed twice as well as previous implementations in both simulations and experiments, exemplified with hyperpolarized ethyl acetate. This concept is expected to extend to other nuclei and other spin order transfer schemes that use non-selective excitation.

Automated summary

In this study, a new pulse sequence was introduced to convert spin order in a molecule after the addition of parahydrogen into C-13 polarization. By using selective preparation instead of non-selective excitation, the new variant outperformed previous implementations in simulations and experiments, showing potential for extension to other nuclei and spin order transfer schemes using non-selective excitation.