Harden M. McConnell
Encyclopedia
Harden M. McConnell is an American
physical chemist at Stanford University
.
. 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 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.
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".
He has also received several awards and honours. Following are the awards and honours received by Dr. McConnell.
California Section Award of the ACS (1961)
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
physical chemist at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
.
Birth and education
Harden M. McConnell was born on July 18, 1927 in Richmond, VirginiaRichmond, Virginia
Richmond is the capital of the Commonwealth of Virginia, in the United States. It is an independent city and not part of any county. Richmond is the center of the Richmond Metropolitan Statistical Area and the Greater Richmond area...
. He completed his Bachelor of Science
Bachelor of Science
A Bachelor of Science is an undergraduate academic degree awarded for completed courses that generally last three to five years .-Australia:In Australia, the BSc is a 3 year degree, offered from 1st year on...
from George Washington University
George Washington University
The George Washington University is a private, coeducational comprehensive university located in Washington, D.C. in the United States...
in 1947 and his PhD from the California Institute of Technology
California Institute of Technology
The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...
in 1951. He is a Robert Eckles Swain Professor at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
.
Research
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
McConnell equation
McConnell equation describes the proportional dependence of the hyperfine splitting constant a on the spin density \rho in aromatic radical compounds such as benzene radical anion C_6H_6^-....
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 ChemistryWolf Prize in Chemistry
The Wolf Prize in Chemistry is awarded once a year by the Wolf Foundation in Israel. It is one of the six Wolf Prizes established by the Foundation and awarded since 1978; the others are in Agriculture, Mathematics, Medicine, Physics and Arts.-Laureates:...
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".
He has also received several awards and honours. Following are the awards and honours received by Dr. McConnell.
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. GutowskyHerbert S. GutowskyHerbert S. Gutowsky was an American chemist who was a Professor of Chemistry at the University of Illinois at Urbana-Champaign. His pioneering work made nuclear magnetic resonance spectroscopy one of the most effective tools in chemical and medical research.- Birth and education :Herbert S...
and John S. WaughJohn S. WaughJohn Stewart Waugh is an American chemist and Institute Professor at the Massachusetts Institute of Technology. He is known for developing average hamiltonian theory and using it to extend NMR spectroscopy, previously limited to liquids, to the solid state...
) (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 ChicagoUniversity of ChicagoThe University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
(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)