Two Synthesizer Nuclear Spin Decoupling; INDOR Spectroscopy

A proton-stabilized, frequency-swept, high resolution NMR spectrometer using a frequency synthesizer was described previously by E. B. Baker and L. W. Burd. The addition of a second synthesizer and suitable power amplification allows a variety of nuclear spin decoupling experiments to be carried out with any pair of nuclear species, including INDOR experiments. For INDOR experiments a dispersion signal lock-on provides extra stability for resting on the peak of a very sharp absorption line. A P31 INDOR spectrum of trimethyl phosphite is shown as an example.