Population transfer HMQC for half-integer quadrupolar nuclei.
This work presents a detailed analysis of a recently proposed nuclear magnetic resonance method [Wang et al., Chem. Commun. 49(59), 6653-6655 (2013)] for accelerating heteronuclear coherence transfers involving half-integer spin quadrupolar nuclei by manipulating their satellite transitions. This method, called Population Transfer Heteronuclear Multiple Quantum Correlation (PT-HMQC), is investigated in details by combining theoretical analyses, numerical simulations, and experimental investigations. We find that compared to instant inversion or instant saturation, continuous saturation is the most practical strategy to accelerate coherence transfers on half-integer quadrupolar nuclei. We further demonstrate that this strategy is efficient to enhance the sensitivity of J-mediated heteronuclear correlation experiments between two half-integer quadrupolar isotopes (e.g., (27)Al-(17)O). In this case, the build-up is strongly affected by relaxation for small T2' and J coupling values, and shortening the mixing time makes a huge signal enhancement. Moreover, this concept of population transfer can also be applied to dipolar-mediated HMQC experiments. Indeed, on the AlPO4-14 sample, one still observes experimentally a 2-fold shortening of the optimum mixing time albeit with no significant signal gain in the (31)P-{(27)Al} experiments.
National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
Qiang
Q
Wang
National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
Yixuan
Y
Li
Unit of Catalysis and Chemistry of Solids (UCCS), CNRS UMR-8181, University of Lille, 59652 Villeneuve d'Ascq, France.
Julien
J
Trébosc
Unit of Catalysis and Chemistry of Solids (UCCS), CNRS UMR-8181, University of Lille, 59652 Villeneuve d'Ascq, France.
Olivier
O
Lafon
National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
Jun
J
Xu
Physics Department and Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China.
Bingwen
B
Hu
National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
Ningdong
N
Feng
Physics Department and Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China.
Qun
Q
Chen
Unit of Catalysis and Chemistry of Solids (UCCS), CNRS UMR-8181, University of Lille, 59652 Villeneuve d'Ascq, France.
Jean-Paul
JP
Amoureux
National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
Feng
F
Deng
D000537:Aluminum Oxide / Q000737:chemistry; D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008956:Models, Chemical; D011789:Quantum Theory
D000537:Aluminum Oxide