Efficient identification of different types of carbons in organic solids by 2D solid-state NMR spectroscopy
writer：Zhang, RC; He, X; Fu, WG; Chen, TH; Sun, PC; Li, BH; Ding, DT
keywords：Carbon Types, Organic Solids, NMR, PISEMA
source：期刊
specific source：Journal of Physical Chemistry A 2011, 115, 11665–11670
Issue time：2011年
The structure and dynamic behavior of mobile components play a significant role in determining properties of solid materials. Herein, we propose a novel real-time spectrum editing method to extract signals of mobile components in organic solids on the basis of the polarization inversion spin exchange at magic angle (PISEMA) pulse sequence and the difference in 13C T1 values of rigid and mobile components. From
the dipolar splitting spectrum sliced along the heteronuclear dipolar coupling dimension of the 2Dspectrum, the structural and dynamic information can be obtained, such as the distances between atoms, the dipolar coupling strength, the order parameter of the polymer backbone chain, and so on. Furthermore, our proposed method can be used to achieve the separation of overlapped NMR signals of mobile and rigid phases in the PISEMA experiment. The high efficacy of this 2D NMR method is demonstrated on organic solids, including crystalline L-alanine, semicrystalline polyamide-6, and the natural abundant silk fibroin.