The Chemistry Prize Committee for 1983/4 has unanimously chosen the following three candidates to equally share the award:
Herbert S, Gutowsky
University of Illinois at Urbana
Urbana, Illinois, USA
for his pioneering work in the development and applications of nuclear magnetic resonance spectroscopy in chemistry
Harden M. McConnell
Stanford University California
Stanford, California, USA
for his studies of the electronic structure of molecules through paramagnetic resonance spectroscopy and for the introduction and biological applications of spin label techniques.
John S. Waugh
Massachusetts Institute of Technology
Cambridge, Massachusetts, USA
for his fundamental theoretical and experimental contributions to high resolution nuclear magnetic resonance spectroscopy in solids.
Magnetic resonance spectroscopy has made a singular contribution to chemistry in theory, structure and dynamics of molecules in liquids and solids. This is reflected in the choice of the recipients of the Wolf Prize in Chemistry for 1983/84.
Professor Herbert S. Gutowsky was the first to apply the nuclear magnetic resonance method to chemical research. His experimental and theoretical work on the chemical shift effect and its relation to molecular structure has provided the chemist with working tools to study molecular conformation and molecular interactions in solutions. Gutowsky´s pioneering work on the spin-spin coupling effect developed this phenomenon into a 'finger print' method for the identification and characterization of organic compounds. He was also the first to observe the effect of dynamic processes on the lineshape of high resolution nuclear magnetic resonance spectra, and exploited it for the studies of hindered rotation in molecules, Simultaneously with others he discovered the effect of the scalar and dipolar interaction with unpaired electrons in solutions of paramagnetic ions.
Professor Harden M. McConnell recognized that the discovery of nuclear hyperfine interactions in aromatic free radicals represented a major breakthrough in the study of the electronic structure of unsaturated hydrocarbons. His theoretical and experimental studies of nuclear hyperfine interactions in such compounds showed conclusively that this interaction gave a measure of the unpaired electron spin densities on the carbon atoms. McConnell´s theoretical and experimental investigations of the anisotropic nuclear hyperfine interaction laid a firm foundation for the analysis of the paramagnetic resonance spectra of organic free radicals in. molecular crystals. His work also provided the first experimental demonstration of
a negative spin density at a proton. Finally, McConnell realized that certain nitroxide free radicals had the potential of providing labels for studying molecular motions. His introduction of 'spin labels' has led to a deep understanding of such motions, and to extensive applications in many biological systems of great interest.
Professor John S. Waugh extended the use of high resolution nuclear magnetic resonance spectroscopy from liquids to solids. He succeeded to sharpen the spectrum in solids, which is naturally broad and diffuse, by effectively averaging the spin Hamiltonian, using special combinations of externally oscillating fields. His studies have significantly deepened the physical and theoretical insights into the nature of the spin Hamiltonian and its role in nuclear magnetic resonance. In particular his method for enhancing the signal of diluted spins in the presence of abundant ones became extremely useful for carbon thirteen nuclear magnetic resonance in organic solids, where polarization transfer from the abundant protons to the rare carbon spins occurs, while at the same time broadening effects are eliminated.