Having trouble assigning clarity to a crowed 1H spectrum with complicated J-coupling splittings … consider using a homonuclear decoupling experiment.

During proton-proton homo-nuclear decoupling, a proton resonance is irradiated during acquisition. If the irradiated proton has a coupling partner, the partner’s multiplet collapses and removes the active coupling. The partner multiplet will still show couplings to other, non-irradiated protons. This allows one to identify the coupling network, i.e., to determine what protons are coupled. Since the partner multiplet is simplified, it can allow one to measure the J value for any remaining couplings.