J-modulated ADEQUATE (JM-ADEQUATE) experiment for accurate measurement of carbon-carbon coupling constants

Research output: Contribution to journalArticle

38 Citations (Scopus)


A new method for the accurate determination of carbon-carbon coupling constants is described. The method is based on a modified ADEQUATE experiment, where a J-modulated spin-echo sequence precedes the ADEQUATE pulse scheme. The J-modulation and scaling of carbon-carbon couplings is based on simultaneous incrementation of 13C chemical shift and coupling evolution periods. The time increment for the homonuclear carbon-carbon coupling evolution can be suitably scaled with respect to the corresponding increment for the chemical shift evolution. Typically a scaling factor of 2 to 3 is employed for the measurement of one-bond coupling constants, while multiplication by a factor of 10 to 15 is applied when small long-range couplings are determined. The same pulse scheme with coupling evolution period optimized for one-bond or long-range couplings allows the determination of the corresponding carbon-carbon coupling constants. The splittings of the ADEQUATE crosspeaks in the F1 dimension yield the appropriately multiplied coupling constants.

Original languageEnglish
Pages (from-to)47-52
Number of pages6
JournalJournal of Magnetic Resonance
Issue number1
Publication statusPublished - Jan 1 2004



  • Carbon-carbon coupling constant
  • J-modulation
  • Long-range coupling constants
  • One-bond coupling constant

ASJC Scopus subject areas

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

Cite this