Improved performance accordion heteronuclear multiple-bond correlation spectroscopy-IMPEACH-MBC.
A modification of the recently reported ACCORD-HMBC long-range heteronuclear shift correlation experiment is described. The new experiment, IMPEACH-MBC (improved performance accordion heteronuclear multiple-bond correlation), introduces a new pulse sequence element, a constant time variable delay. The incorporation of the constant time variable delay into the IMPEACH-MBC sequence suppresses (1)H-(1)H coupling modulation inherent to the utilization of the accordion principle to sample a broad range of potential long-range heteronuclear couplings. (1)H-(1)H coupling modulation, which introduces an F(1) modulation or a "skew" of responses in the second frequency domain of the ACCORD-HMBC experiment, is suppressed in the IMPEACH-MBC experiment. Results of identically optimized IMPEACH-MBC and ACCORD-HMBC experiments performed on a sample of strychnine are compared.
Hadden
C E
CE
Pharmaceutical Development, Pharmacia & Upjohn, Kalamazoo, Michigan 49001-0199, USA.
Martin
G E
GE
Krishnamurthy
V V
VV
D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015394:Molecular Structure; D013331:Strychnine / Q000737:chemistry*
D013331:Strychnine