Introduction

A comprehensive unit covering the entirety of NMR spectroscopy could easily fill an entire semester course. The goal of this unit is to develop introductory concepts on NMR spectroscopy that are most relevant for undergraduate chemistry majors. Furthermore, there are some topics developed in this unit where a rigorous coverage would lengthen the discussion and likely confuse a beginner. In these instances, the concept under development has been simplified so that the important consequences that relate to the resulting NMR spectrum are appreciated. Development of the concepts of NMR is accomplished through an examination of the normal hydrogen (¹H) nucleus. The unit is focused on understanding what occurs in molecules and within the NMR spectrometer that causes ¹H NMR spectra to look the way they do. There is less of an emphasis on interpreting NMR spectra, although the concepts developed herein provide students with the understanding needed to begin interpreting NMR spectra. Components of both a quantum mechanical and classical description of NMR spectroscopy are developed.

It is helpful to examine the words in “nuclear magnetic resonance spectroscopy” to consider some aspects of this area. “Nuclear” indicates that the technique probes some aspect of the nuclei of atoms. “Magnetic” indicates that magnetic fields must be involved with this technique. “Resonance” indicates that some energy transition between a ground and excited state is being probed. And finally, “spectroscopy” indicates that the energy transition is excited through the use of appropriate frequencies of electromagnetic radiation.