¹H NMR Studies of Plastic Organic Solids

The ¹H MAS spectrum of a plastic organic solid is usually composed of a high-resolution component and a breadline component. The high-resolution component corresponds to a plastic phase, while the broadline component corresponds to the rigid phase. The high-resolution spectrum of the plastic phase can be observed by the echo-MAS experiment with a long echo time; the high-resolution spectrum of the whole ¹H system can be observed by the CRAMPS technique, mainly coming from the contribution of the rigid phase at usual temperature. It is shown that combination of CRAMPS with ¹H MAS and echo-MAS is an effective way for studying the ratio of the plastic phase to the rigid phase, molecular structure and states of motion in organic solids.