Selective measurement of ^{11 H– 11 H scalar couplings from crowded chemical shift regions: Combined pure shift and spin‐echo modulation approach}

摘要

> J _HH scalar couplings carry rich structural information and their measurements are fundamental in the 1 H NMR based elucidation of small and medium molecules, which, however, are hampered in the presence of large J ‐coupling network. Further, enhanced spectral resolution is often essential for precise determination of a specific set of 1 H– 1 H J ‐couplings among the complex J ‐multiplets. In the light of the recent advancements in homodecoupling pure shift strategies, here, we report absorption mode, band‐selective refocused pure shift spin‐echo method, which helps in determining 1 H– 1 H J ‐couplings from crowded spectral regions. The importance of the present band‐selective refocused pure shift spin‐echo experiment is exemplified for 2 steroid molecules, estradiol and testosterone.