Harden M. McConnell (July 18, 1927 – October 8, 2014) was an American physical chemist. His many awards included the National Medal of Science and the Wolf Prize, and he was elected to the National Academy of Science."

Education and career

Harden earned a B.S. degree in chemistry from George Washington University in 1947, and his Ph.D. in chemistry from the California Institute of Technology in 1951 with Norman Davidson. After serving for two years as a National Research Fellow in physics at the University of Chicago with Robert S. Mulliken and John Platt, he held a position as research chemist at Shell Development Company. He was recruited by Norman Davidson, John D. Roberts, and

Linus Pauling Linus Carl Pauling (; February 28, 1901August 19, 1994) was an American chemist, biochemist, chemical engineer, peace activist, author, and educator. He published more than 1,200 papers and books, of which about 850 dealt with scientific top ...

at the California Institute of Technology in 1956 as Assistant Professor of Chemistry, he was promoted to Professor of Chemistry and Physics in 1963, and in 1964 he moved to

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

as a professor. In 1979 he was named Robert Eckles Swain Professor of Chemistry at Stanford University. From September 1989 to September 1992, he was Head of the Department of Chemistry at Stanford. On September 1, 2000, Harden was granted Emeritus status.

Research

McConnell did important research to the understanding of 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 In physical chemistry, the McConnell equation gives the probability of an unpaired electron in an in aromatic radical compound (such as benzene radical anion C_6H_6^-) being on a particular atom. It relates this probability, known as the "spin dens ...

for details). His theoretical and experimental investigations of the anisotropic nuclear hyperfine interactions 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 nitric oxide 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. These motions include the rates of translational diffusion of lipids in bilayer membranes as well as the rates of trans membrane phospholipid "flip-flop". In fact nitric oxide free radical "spin labels" provided some of the earliest evidence for the fluidity of biological membranes. His later research was 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. An important contribution was the introduction of supported lipid bilayers to mimic cell surfaces. For example, this system was used to mimic antigen presentation whereby a specific molecule of the major histocompatibility complex is incorporated into the bilayer, a specific antigenic peptide is added, and the combined system used to stimulate a specific T - helper cell. In 1983 McConnell founded Molecular Devices Corporation along with three former graduate students and post docs (Gillian Humphries, j. Wallace Parce and Dean Hafeman) together with a talented engineer, Calvin Chow. The company produced instrumentation for biochemical analysis and drug discovery. The company had over 1,000 employees when it was acquired in 2007. McConnell served on the Board of Directors between 1983 and 2007. "The majority of the 150 scientists who worked with Harden as graduate students, postdocs, and senior colleagues, attended a symposium on April 4, 1992, at Stanford University, in celebration of Harden's 65th birthday. As an outgrowth of that symposium, these scientists organized special issues of the ''Biophysical Journal'' and ''The Journal of Physical Chemistry'' to present current aspects of their work and his. Several other scientists whose work has been influenced by McConnell's contributed articles also. The symposium and these papers provide powerful testimony to the profound impact that Harden McConnell has had in the fields of chemical physics, molecular biophysics, and cellular biophysics. McConnell's influence comes not only from his own impressive publication list, but also from the scores of scientists whose careers he has inspired, by his example of intellectual brilliance, and personal integrity." "The McConnell Book: Biographical Sketches and Memoirs of Students and Lab Associates in Celebration of Harden M. McConnell's 65th Birthday," was also published. An updated and expanded version of Harden's research and publications is available as a website.

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". He has also received several

awards An award, sometimes called a distinction, is something given to a recipient as a token of recognition of excellence in a certain field. When the token is a medal, ribbon or other item designed for wearing, it is known as a decoration. An award ...

and honours. Following are the

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 The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

(1965) * Harrison Howe Award, ACS (1968) *

Irving Langmuir Award The Irving Langmuir Prize in Chemical Physics is awarded annually, in even years by the American Chemical Society and in odd years by the American Physical Society. The award is meant to recognize and encourage outstanding interdisciplinary resear ...

in Chemical Physics, American Chemical Society (1972) * International Academy of Quantum Molecular Sciences (1974)? * Elected Fellow of the American Association for the Advancement of Science (1982) *

Dickson Prize for Science The Dickson Prize in Medicine and the Dickson Prize in Science were both established in 1969 by Joseph Z. Dickson and Agnes Fischer Dickson. Dickson Prize in Medicine The Dickson Prize in Medicine is awarded annually by the University of Pittsburg ...

, Carnegie-Mellon University (1982) * ISCO Award (1984) * Wolf Prize (shared with

Herbert S. Gutowsky Herbert Sander Gutowsky (November 8, 1919 – January 13, 2000) was an American chemist who was a Professor of Chemistry at the University of Illinois Urbana-Champaign. Gutowsky was the first to apply nuclear magnetic resonance (NMR) methods ...

and

John S. Waugh John Stewart Waugh (April 25, 1929 – August 22, 2014) was 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 s ...

) (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 (Chemistry) (1989) *

Peter Debye Award The Peter Debye Award in Physical Chemistry is awarded annually by the American Chemical Society "to encourage and reward outstanding research in physical chemistry". The award is named after Peter Debye and granted without regard to age or natio ...

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) * Serbian Academy of Sciences and Arts (1997) * Biophysical Society Fellow (1999) * Zavoisky Award (2000) * Welch Award in Chemistry (2002) * Fellow, Royal Society of Chemistry (2008) * Fellow, International ESR/EPR Society (2014)

Personal life

Harden M. McConnell was born on July 18, 1927, in Richmond, Virginia and his interest in science, particularly chemistry, began when he discovered a box of copper sulfate crystals in the basement of his home at the approximate age of 12. He died on Wednesday, October 8, 2014.

References

External links

Research Studies of Harden M. McConnell (Autobiographical)

Harden M. McConnell's Citation Profile on Google Scholar

Student Theses (Harden M. McConnell as Primary Advisor)

The Wolf Prize in Chemistry in 1984/85

Harden M. McConnell at the International Academy of Quantum Molecular Science
{{DEFAULTSORT:McConnell, Harden M. 1927 births Columbian College of Arts and Sciences alumni California Institute of Technology alumni Stanford University Department of Chemistry faculty Wolf Prize in Chemistry laureates Members of the Serbian Academy of Sciences and Arts 2014 deaths National Medal of Science laureates Members of the United States National Academy of Sciences American physical chemists