Shao Limin, Titman Jeremy J
School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
J Chem Phys. 2006 Aug 14;125(6):64507. doi: 10.1063/1.2207616.
An alternative magic angle spinning (MAS) exchange NMR experiment based on chemical shift anisotropy (CSA) amplification is described. The CSA amplification experiment correlates a standard MAS spectrum in the omega(2) dimension with a sideband pattern in omega(1) in which the intensities are identical to those expected for a sample spinning at some fraction 1N of the actual rate omega(r). In common with 2D-PASS, the isotropic shift appears only in the omega(2) dimension, and long acquisition times can be avoided without loss of resolution of different chemical sites. The new CSA amplification exchange experiment provides information about the time scale and geometry of molecular motions via their effect on the sideband intensities in a one-dimensional pattern. The one-dimensional patterns from different chemical sites are separated across two frequency dimensions according to the isotropic shifts.
描述了一种基于化学位移各向异性（CSA）放大的替代魔角旋转（MAS）交换核磁共振实验。CSA放大实验在ω(2)维度上使标准MAS谱与ω(1)中的边带模式相关联，其中边带强度与以实际旋转速率ω(r)的某个分数1/N旋转的样品所预期的强度相同。与二维PASS一样，各向同性位移仅出现在ω(2)维度中，并且可以避免长时间采集而不损失不同化学位点的分辨率。新的CSA放大交换实验通过其对一维模式中边带强度的影响，提供了有关分子运动的时间尺度和几何结构的信息。来自不同化学位点的一维模式根据各向同性位移在两个频率维度上分开。
