The Nature of NMR Absorptions The absorption frequency is not the same for all 1H and 13C nuclei Each chemically distinct nucleus in a molecule has a slightly different electronic environment and consequently a different effective field Each chemically distinct 13C or 1H nucleus in a molecule experiences a different effective field and will exhibit a distinct 13C or 1H NMR signalThe absorption frequency is not the same for all 1H and 13C nuclei ▪ Each chemically distinct nucleus in a molecule has a slightly different electronic environment and consequently a different effective field ▪ Each chemically distinct 13C or 1H nucleus in a molecule experiences a different effective field and will exhibit a distinct 13C or 1H NMR signal The Nature of NMR Absorptions