ID One-dimensional NMR Methods

A convenient collection of explanations of some of the terminology of NMR spectroscopy to which some may wish to refer is the monograph, A Handbook of Nuclear Magnetic Resonance, by Freeman [13]. In addition, there are also numerous monographs dealing with various aspects of NMR that have appeared over the last 10—15 years that are worthy of note [14—32]. Those cited are by no means intended to be an exhaustive compilation, but rather are those volumes that the authors have found useful. 

The simplest ID NMR experiments involve the apphcation of a pulse followed by observation of the resulting signal in the time domain, with subsequent Fourier transformation of the data to the frequency domain for presentation in a format that we, as chemists, can understand. Pulsed NMR methods had their inception in 1966 [33] and have almost completely supplanted earlier continuous wave (CW) methods. For reasons of sensitivity, only ID NMR spectra were typically acquired prior to the 1970s. The advent of pulsed Fourier transform NMR instruments made it possible to acquire natural abundance C NMR spectra on a routine basis in the early 1970s. With the routine availabihty of C NMR data came the compilation of chemical shift data bases and a very different way of approaching chemical structure elucidation. 

We will briefly consider in this section various aspects of homonuclear spin-de-coupling experiments and nuclear Overhauser effect (NOE) difference spectra. Obviously any detailed treatment is far beyond the size limitations of this chapter. Moving next to ID NMR techniques, we wiU briefly consider the utilization of selective spin-population transfer (SPT) and experiments which rely on these principles such as INEPT and DEPT, off-resonance proton decoupling techniques, decoupler gating experiments, and finally spin—lattice or Tj relaxation techniques. 

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