Harden M. McConnell
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 Birth and education
Harden M. McConnell was born on July 18, 1927 in Richmond, Virginia. He completed his Bachelor of Science from George Washington University in 1947 and his PhD from the California Institute of Technology in 1951. He is a Robert Eckles Swain Professor at Stanford University.
He did important research to the understand the relation between molecular electronic structure and electron and nuclear magnetic resonance spectra during the period of 1955 through 1965. After that, he developed the technique of spin-labels, whereby electron and nuclear magnetic resonance spectra can be used to study the structure and kinetics of proteins and membranes.
He 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 (see McConnell equation for details). His 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. He also 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.
His recent research concerned with the physical chemistry of biological membranes. These studies range all the way from lipid monolayers at the air-water interface to the regions of membrane-membrane contact that are important in immunology.
 Awards and honours
He was awarded the Wolf Prize in Chemistry in 1983/84 for "his studies of the electronic structure of molecules through paramagnetic resonance spectroscopy and for the introduction and biological applications of spin label techniques".
California Section Award of the ACS (1961)
- National ACS Award in Pure Chemistry (1962)
- Election to the National Academy of Sciences (1965)
- Harrison Howe Award, ACS (1968)
- Irving Langmuir Award in Chemical Physics (1971)
- Elected Fellow of the American Association for the Advancement of Science (1982)
- Dickson Prize for Science, Carnegie-Mellon University (1982)
- ISCO Award (1984)
- Wolf Prize (shared with Herbert S. Gutowsky and John S. Waugh) (1984)
- Pauling Medal, Puget Sound and Oregon ACS Sections (1987)
- Wheland Medal, University of Chicago (1988)
- U.S. National Academy of Sciences Award in Chemical Sciences (1988)
- National Medal of Science (1989)
- Peter Debye Award in Physical Chemistry, ACS (1990)
- Doctor of Science, University of Chicago (Honorary) (1991)
- Bruker Prize, Royal Society of Chemistry (1995)
- ACS Award in Surface Chemistry (1997)
- Biophysical Society Fellow (1999)
- Zavoisky Award (2000)
- Welch Award in Chemistry (2002)