Hadamard Long-Range Proton-Carbon Coupling Constant Measurements with Pulsed Field Gradients

• Published in: Magnetic resonance in chemistry Vol. 34; no. 5; pp. 377 - 382
• Main Authors: Nishida, T., Widmalm, G., Sándor, P.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-05-1996
• Subjects: 1,6‐anhydro‐β‐D‐galactopyranoside; 3-acetylpyridine; 6-anhydro-β-D-galactopyranoside; band-selective homonuclear decoupling; Hadamard spectroscopy; J-doubling; long-range13C-1H coupling constants; multiple-selective excitation; pulsed field gradients
• ISSN: 0749-1581; 1097-458X
• DOI: 10.1002/(SICI)1097-458X(199605)34:5<377::AID-OMR893>3.0.CO;2-U

Sources of artifacts in Hadamard spectra were investigated and identified as insufficient suppression of signals from solvent, protons attached to 12C atoms and error signals caused by non‐ideal excitation and the subsequent Hadamard transformation. Pulsed field gradients (PFG) effectively eliminate the former error signals while re‐optimized Hadamard‐shaped pulses produce practically ideal excitation and Hadamard transformation affords artifact‐free spectra. Long‐range 13C–1H coupling constants of 1,6‐anhydro‐β‐D‐galactopyranoside and 3‐acetylpyridine were determined by using a PFG pulse sequence and re‐optimized Hadamard‐8 shaped pulses.