Swept-frequency two-pulse phase modulation for heteronuclear dipolar decoupling in solid-state NMR

We introduce a heteronuclear dipolar decoupling sequence for application in solid-state nuclear magnetic resonance. The sequence, called swept-frequency two-pulse phase modulation (SWf-TPPM), is based on one of the decoupling sequences, TPPM. The sequence is robust in performance with respect to various experimental parameters, such as, the pulse flip angle, pulse phase, and offset and a comparison is made with other decoupling schemes, namely TPPM, SPINAL, and XiX, on a sample of U–13C-labelled tyrosine for magic-angle spinning speeds up to 14 kHz.