Broad-band homo-nuclear correlations assisted by 1H irradiation for bio-molecules in very high magnetic field at fast and ultra-fast MAS frequencies |
| |
Authors: | Hu Bingwen Lafon Oliver Trébosc Julien Chen Qun Amoureux Jean-Paul |
| |
Institution: | aPhysics Department, Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China;bUCCS, Lille North of France University, Villeneuve d’Ascq 59652, France |
| |
Abstract: | We propose a new broadband second-order proton-assisted 13C–13C correlation experiment, SHANGHAI. The 13C–13C magnetization transfer is promoted by 1H irradiation with interspersed four phases super-cycling. This through-space homo-nuclear sequence only irradiates on the proton channel during the mixing time. SHANGHAI benefits from a large number of modulation sidebands, hence leading to a large robustness with respect to chemical shift differences, which permits its use in a broad MAS frequency range. At ultra-fast MAS (νR ? 60 kHz), SHANGHAI is only efficient when the amplitude of 1H recoupling rf-field is close to half the spinning speed (ν1 ≈ νR/2). However, at moderate to fast MAS (νR = 20–35 kHz), SHANGHAI is efficient at any rf-power level larger than ν1 ≈ 10 kHz, which simultaneously permits avoiding excessive heating of bio-molecules, and using large sample volumes. We show that SHANGHAI can be employed at the very high magnetic field of 23.5 T and then allows the observation of correlation between 13C nuclei, even if their resonance frequencies differ by more than 38 kHz. |
| |
Keywords: | Solid-state NMR Indirect homo-nuclear correlation Bio-molecules Ultra-fast MAS Very-high magnetic field |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|