The influence of fluorine spin-diffusion on C solid-state NMR line shapes of CF groups.

Indirect spin-spin couplings ("J-couplings") lead to well-known multiplet patterns in nuclear magnetic resonance (NMR) spectra that are also observable in non-decoupled solid-state NMR spectra, if the J-coupling constant exceeds the linewidth. Such J-multiplet line shapes in the solid state might however be affected by spin diffusion (SD) on the passive nuclei. When the SD rate constant is fast compared to the J-coupling constant, the multiplet resolution can be lost due to a so-called "self-decoupling" mechanism as has been already reported in the context of decoupling and for proton SD in solid adamantane.