Gradient Enhanced HMBC

HMBC (heteronucler multiple bond correlation) experiment reveals J couplings (through-bond) across multiple bonds between 1H and 13C nuclei. The following is the recommended gradient enhanced HMBC pulse sequence. No 13C decoupling is applied during acquisition. As a result, the fine splitting along 1H reflects the 1H<->13C J couplings in addition to homonuclear 1H<->1H couplings.

gHMBC sequence

Procedure

Example

Sample: Strychnine at ~ 25mg/mL (~ 100mM) in cdcl3
  • Data collected October 2010 (~17 mins with nt=4 ni=200)
  • Qurdrature detection: absolute-value mode
  • 13C centered at 90ppm with a 240ppm spectral width.
  • Processed and displayed with nmrPipe/nmrDraw
Strychnine

Strychnine

gHMBC spectrum of Strychnine

Strychnine gHMBC


H. Zhou Updated Oct 2010