CLIP-HSQMBC: easy measurement of small proton-carbon coupling constants in organic molecules
Josep Saurí1, Teodor Parella, Juan F Espinosa
1Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, 08193-Bellaterra, Barcelona, Spain.
Abstract:
A user-friendly 2D NMR approach denoted as CLIP-HSQMBC is proposed for the very easy, direct and accurate measurement of long-range proton-carbon coupling constants in organic molecules and natural products. The J value can be extracted directly from the analysis of resolved in-phase (1)H multiplets that show an additional splitting arising from the proton-carbon coupling. In cases of unresolved peaks, a simple fitting analysis using the internal satellite lines as a reference is performed. Addition of a spin-lock period results in a CLIP-HSQMBC-TOCSY experiment that is suitable for the measurement of very small coupling values or to observe correlations from overlapped resonances.
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