Xia Y, Deng F, Ye C
Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Chinese Academy of Sciences, Wuhan, People's Republic of China.
Solid State Nucl Magn Reson. 1995 Dec;5(3):227-32. doi: 10.1016/0926-2040(95)01185-4.
The off-resonance effects on 2D NMR nutation of I = 3/2 quadrupolar nuclei are demonstrated with perturbation theory and numerical calculation in static samples. The off-resonant (delta omega) rf field (omega 1) enlarges a nutation frequency and consequently increases the measurement range of nuclear quadrupolar interaction parameters. When omega e > omega Qmax, and arctg(omega 1/delta omega) = +/- 54.7 degrees (magic angle), the satellite lines (produced by coherence transfers) in a nutation spectrum are superimposed with the line of central transition, and hence the nutation spectrum is simplified and its sensitivity is enhanced. The nuclear quadrupolar interaction parameters of 23Na nuclei in Na omega molecular sieve are obtained using 2D NMR nutation.
利用微扰理论和数值计算，在静态样品中展示了偏离共振对I = 3/2四极核二维核磁共振章动的影响。偏离共振（δω）射频场（ω1）增大了章动频率，从而扩大了核四极相互作用参数的测量范围。当ωe > ωQmax，且arctg(ω1/δω) = +/- 54.7°（魔角）时，章动谱中（由相干转移产生的）卫星线与中心跃迁线重叠，因此章动谱得到简化且灵敏度提高。利用二维核磁共振章动获得了钠ω分子筛中23Na核的核四极相互作用参数。
