Instrumentation and Measurement of Nuclear Magnetic Triple Resonance Including 14 N Resonance

Abstract

A bridge-type high-resolution NMR spectrometer has been modified to yield a triple-resonance spectrometer which decouples two kinds of interaction, ¹⁴N-¹H and ¹H-¹H. The instrumentation of this modification is described in detail. The conditions for decoupling the UN interaction with proton were investigated experimentally, especially the dependence of the proton resonance resolution on both power and frequency of the rf field corresponding to the UN resonance. It is pointed out that the resonance frequency of the ¹⁴N nucleus can be measured with high accuracy using this double-resonance technique. The triple-resonance technique was applied to pyrrole, and was successful in obtaining the finely resolved spectrum and in attributing the spin-spin couplings to the interactions between specified groups of proton.