NMR studies of other nuclei

Phosphorus is an abundant spin- nucleus that occurs more frequently in biopolymers than in synthetic polymers. In biopolymers, the chemical shifts are related to the phosphate conformation and the ionisation state. Phosphorus NMR has been used to characterise synthetic polymers such as poly(phosphazines) [13]. The P chemical shifts provide a probe of the polymer backbone in such polymers. 

Nitrogen is a commonly occurring element in many polymers, such as nylons, polyimides, and biopolymers. The use of N-NMR to characterise these materials is limited in sensitivity by the low magnetogyric ratio and natural abundance. These materials can be studied in concentrated solutions or by the synthesis of materials enriched with N. The results show that the N chemical shifts are extremely sensitive to the polymer sequence and environment. The chemical shifts can be used to study the conformation of biopolymers in important materials such as silk and wool. 

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