Effects of a solid proton transfer on the 13C, 14N residual dipolar coupling in CPMAS NMR. Implications for the shape of the potential energy function

Abstract

A rapid spin–lattice ¹⁴N relaxation caused by an N–H proton transfer reaction in the solid state is likely to affect the ¹³C, ¹⁴N residual dipolar coupling generally observed in ¹³C CPMAS spectroscopy. A simple analysis is presented for studying the conditions under which the carbon resonances will be self-decoupled from the influence of ¹⁴N nuclei. The implications of the results as to the nature of the proton potential energy profile are also discussed.