固体核磁共振魔角旋转条件下的定量交叉极化技术(英文)

交叉极化与魔角旋转结合（CP/MAS）的方法已经成为增强固体核磁共振（NMR）检测灵敏度最重要的技术之一.CP/MAS技术的应用大大提高了固体NMR谱图的采集效率.然而，I-S偶极耦合作用、旋转坐标系下的自旋-晶格弛豫、分子运动，以及样品中丰核的分布情况等因素，通常会导致CP/MAS谱图失去定量作用.近年来，多个研究组通过改进或者设计新型固体NMR脉冲序列，获得了基于CP的可用于定量分析的固体NMR谱图.本综述首先简要介绍了CP及CP动力学，随后介绍了一系列基于CP的定量固体NMR信号增强技术，具体包括ramped-amplitude CP（RAMP-CP）、multiple-contact CP、quantification of CP（QCP）、Lee-Goldburg frequency modulated CP（LG-FMCP）和quantitative CP（QUCP）.

Quantitative Cross Polarization Magic-Angle Spinning NMR Spectroscopy in Solids

The combination of cross polarization and magic-angle spinning (CP/MAS), is a routine technique for signal enhancement in solid-state nuclear magnetic resonance (NMR) spectrum. With CP/MAS, the acquisition efficiency of solid-state NMR experiments can be improved greatly. However, the enhanced signal is not quantitative according to the different CP dynamics dominated by several factors including heteronuclear dipolar couplings, spin-lattice relaxation times in the rotating frame, molecular motions, number of around abundant spins, and so on. Over the years, numerous efforts have been made to obtain quantitative CP/MAS spectroscopy. This review firstly briefly illustrated the introduction of CP and CP dynamics, and then a series of quantitative NMR methods based on CP were introduced, including ramped-amplitude CP (RAMP-CP), multiple-contact CP, quantification of CP (QCP), Lee-Goldburg frequency modulated CP (LG-FMCP) and quantitative CP (QUCP).