论文部分内容阅读
在核磁共振(NMR)领域,~(13)C-NMR是应用比较广泛的常规方法.但对于一些样品,如高聚物或生物大分子,其~(13)C谱中各信号峰互相重叠,这给谱的解析带来了困难.对液体样品,有许多技术如无畸变极化传递增强方法(DEPT)等可简化复杂的图谱,它们是根据与碳原子直接成键的氢原子个数来区分不同的~(13)C信号.而对固体样品,虽然用交叉极化(CP)结合魔角旋转(MAS)及质子大功率去耦技术可获得高分辨~(13)C谱,但对严重重迭的谱,也急需发展谱编辑技术.近年来,吴肖令等在深入研究交叉极化动力学的基础上,提出了固体~(13)C CPMAS谱的谱编辑技术,应用该方法,可以得到分别仅含C,CH,CH_2,CH_3信号峰的各个子谱,从而大大简化了图谱,给谱的解析带来了极大的方便,因而在固体NMR领域内引起了广泛的注意.
In the field of nuclear magnetic resonance (NMR), ~ (13) C-NMR is a widely used conventional method, but for some samples, such as polymers or biological macromolecules, the signal peaks in the ~ (13) C spectrum overlap with each other , Which has caused difficulties in the resolution of the spectra.For liquid samples, there are many techniques such as the DEPT method to simplify complex maps based on the number of hydrogen atoms directly bonded to a carbon atom (13) C signals, whereas for solid samples, high-resolution (13) C spectra were obtained using cross-polarization (CP) combined with magic angle rotation (MAS) and proton power decoupling In the recent years, Wu Xiao-Ling et al. Proposed the spectrum editing technique of the solid -13C CPMAS spectrum based on the in-depth study of the cross polarization kinetics. By applying this method, The spectra of C, CH, CH_2 and CH_3 signal peaks can be obtained respectively, which greatly simplifies the spectra and brings great convenience to the analysis of spectra. Therefore, extensive attention has been paid to the field of solid state NMR.