| Citation | Richard Ernst is a world-famous pioneer in high resolution nuclear magnetic resonance research and has created a whole new methodology of NMR spectroscopy. His early work (with Dr W.A. Anderson in the United States) introduced the Fourier transform method, which revolutionized the field by enhancing sensitivity by two orders of magnitude, paving the way for the study of the "difficult" nuclear species such as carbon-13. A second factor that made carbon-13 spectroscopy practically feasible was a further sensitivity improvement afforded by noise decoupling, a concept developed by Ernst out of his Ph.D. thesis work on stochastic excitation. The Fourier transform method has also opened up an entire family of time-dependent NMR experiments, including spin relaxation studies, chemical exchange, and the nuclear polarization resulting from the recombination of transient free radicals. Virtually all NMR spectrometers now employ the Fourier transform method. These innovations initiated an explosive growth in NMR studies of the less-common nuclear species. Inspired by a proposal of Professor Jeener, Ernst went on to develop the extremely fruitful concept of multidimensional NMR spectroscopy. This addresses the problem that many molecules of chemical interest generate NMR spectra that are grossly overcrowded. Spreading this information into two or more frequency dimensions permits the resolution and assignment of features that would normally be obscured by multiple overlap. Two-dimensional NMR spectra are now used routinely by structural chemists and impressive progress has been made in applying these methods to the larger molecules encountered in molecular biology. In particular, Ernst's studies of the transient nuclear Overhauser effect have led to new methods for measuring interproton distances within macromolecules, giving vital information about the tertiary structure of proteins and other biologically important species in solution. The principle of multidimensional spectroscopy has also had an important impact on magnetic resonance imaging (introduced by Professors Lauterbur and Mansfield) which seems set to supersede the earlier X-ray tomography technique for medical "scanners". Ernst's introduction of the three-dimensional Fourier transform technique is the basis of one widely-used method of magnetic resonance imaging. His most recent experiments have extended these new multidimensional techniques to time-domain electron spin resonance with considerable success. It would be no exaggeration to say that, almost single-handedly, Ernst has created a completely new field of magnetic resonance, and his undisputed leadership has recently been recognized by many international honours, including the Wolf Prize (1991) and the Nobel Prize for Chemistry (1991). |