Sadet A, Fernandes L, Kateb F, Balzan R, Vasos P R
Laboratoire de Chimie et Biochimie Toxicologiques et Pharmacologiques UMR-8601, Université Paris Descartes - CNRS, PRES Paris Sorbonne Cité, 75006 Paris, France.
J Chem Phys. 2014 Aug 7;141(5):054203. doi: 10.1063/1.4891565.
Long-lived coherences (LLC's) are detectable magnetisation modes with favourable relaxation times that translate as sharp resonances upon Fourier transform. The frequency domain of LLC's was previously limited to the range of J-couplings within pairs of homonuclear spins. LLC evolution at high magnetic fields needs to be sustained by radio-frequency irradiation. We show that LLC-based spectral dispersion can be extended beyond the J-couplings domain using adapted carrier offsets and introduce a new reduced-power sustaining method to preserve LLC's within the required range of offsets. Spectral resolution is enhanced as the natively narrow lines of LLC's are further dispersed, making them potential probes for the study of biomolecules featuring strong resonance overlap and for media where NMR spectroscopy is commonly hindered by line broadening.
长寿命相干（LLC）是具有良好弛豫时间的可检测磁化模式，经傅里叶变换后表现为尖锐的共振。LLC的频域以前局限于同核自旋对之间的J耦合范围。在高磁场下，LLC的演化需要通过射频辐射来维持。我们表明，使用适配的载波偏移，基于LLC的谱色散可以扩展到J耦合域之外，并引入一种新的低功率维持方法，以在所需的偏移范围内保持LLC。随着LLC本身的窄线进一步分散，光谱分辨率得到提高，这使得它们成为研究具有强共振重叠的生物分子以及核磁共振光谱通常因谱线展宽而受阻的介质的潜在探针。
