fig9

Figure 9. (A) Pulse sequence of RINEPT-$$ \mathrm{SR4_{1}^{2}} $$ (tt)-QCPMG used to transfer the DNP-enhanced ¹H polarization to the half-integer quadrupolar nucleus, S; (B) ^47/49Ti QCPMG NMR spectra of unmodified MoO₃/TiO₂ enhanced by indirect DNP using ¹H → ^47/49Ti RINEPT-$$ \mathrm{SR4_{1}^{2}} $$ (tt) transfer and DFS scheme; (C) ⁹⁵Mo QCPMG spectra enhanced by indirect DNP using ¹H → ⁹⁵Mo RINEPT-$$ \mathrm{SR4_{1}^{2}} $$ (tt) transfer of MoO₃/TiO₂ and by DFS of MoO₃/TiO₂ and α-MoO₃. Reproduced with permission from^[131]. Copyright 2020, American Chemical Society. RINEPT: Refocused insensitive nuclei enhanced by polarization transfer; QCPMG: quadrupolar Carr-Purcell Meiboom-Gill; DNP: dynamic nuclear polarization; NMR: nuclear magnetic resonance; DFS: double-frequency sweep.