Application of Homonuclear INDOR to a Study of the PMR Spectrum of 15N-pyrrole

Homonuclear INDOR method has been applied to investigate the assignment of some lines of the PMR spectrum of 15N-pyrrole to the transitions in the energy level diagram of the AA'BB'C spin system. This study, based on the characters of some connected transitions and the corresponding line positions, shows that the couplings 1JNH , 2JNH and 3JNH carry the same signs, which is in accordance with a result obtained by the tickling method.