The popular PISEMA experiment is highly sensitive to the 1H chemical shift dispersion and the choice of the 1H carrier frequency. This is due to the off-resonance 1H irradiation in the FSLG-CP sequence employed during the dipolar evolution period. In the modified approach described in this work, the interfering frequency offset terms are suppressed. In the new pulse schemes, conventional FSLG-CP is intercalated with 180° pulses applied simultaneously to both frequency channels, and with phases set orthogonal to those of the spin-lock fields. The technique is demonstrated on a nematic liquid-crystalline sample. Extensions to amplitude-modulated FSLG-CP recoupling under MAS are also presented.

Original languageEnglish
Pages (from-to)163-169
Number of pages7
JournalJournal of Magnetic Resonance
Volume175
Issue number1
DOIs
StatePublished - 1 Jul 2005

    Scopus subject areas

  • Biophysics
  • Biochemistry
  • Nuclear and High Energy Physics
  • Condensed Matter Physics

    Research areas

  • Cross-polarization, Dipolar couplings, MAS, PISEMA, Separated local field spectroscopy

ID: 48949020