Michael James Stanley Dewar (23 January 1918 – 28 October 1997) was a British theoretical and computational chemist noted for his pioneering contributions to quantum chemistry, molecular orbital theory, and the study of aromatic compounds.
Early life and education
Dewar was born in London, England. He pursued his higher education at the University of Cambridge, where he earned a Bachelor of Arts (BA) and later a Doctor of Philosophy (PhD) under the supervision of J. E. G. G. M. E. Saunders. His doctoral research focused on the application of quantum mechanical methods to chemical problems.
Academic career
After completing his PhD, Dewar held research positions at the University of Cambridge and the Imperial College London. In 1956, he was appointed Professor of Theoretical Chemistry at the University of Cambridge, a post he retained until his retirement in 1983. He also served as a Fellow of Trinity College, Cambridge, and played a central role in establishing the Cambridge Workshop in Theoretical Chemistry, fostering interdisciplinary collaboration between chemists and physicists.
Scientific contributions
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Dewar benzene and Dewar quinone: Dewar proposed alternative isomeric structures for benzene (now termed "Dewar benzene") and for quinone, contributing to the understanding of non‑planar aromatic systems.
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Molecular orbital theory: He advanced semi‑empirical molecular orbital methods, developing computational approaches that made quantum‑chemical calculations feasible for larger molecules.
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Dewar–Chatt–Dunham model: In collaboration with A. F. Chatt and J. D. Dunham, Dewar formulated a model describing the bonding in organometallic complexes, which remains a foundational concept in inorganic chemistry.
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Aromaticity and conjugation: His theoretical work elucidated the electronic basis of aromatic stabilization, influencing later models of aromaticity and anti‑aromaticity.
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Publications: Dewar authored over 200 scientific papers and several influential books, including The Geometry of Molecules (1970) and Semiempirical Molecular Orbital Theory (1971).
Honours and awards
- Fellow of the Royal Society (FRS), elected 1969.
- Davy Medal of the Royal Society (1975) for his contributions to theoretical chemistry.
- Commander of the Order of the British Empire (CBE), awarded 1979.
Legacy
Michael J. S. Dewar is regarded as one of the foremost figures in 20th‑century theoretical chemistry. His methods laid the groundwork for modern computational chemistry, and his models continue to be taught in undergraduate and graduate curricula worldwide.
Selected publications
- Dewar, M. J. S. The Geometry of Molecules. Oxford University Press, 1970.
- Dewar, M. J. S. Semiempirical Molecular Orbital Theory. Wiley, 1971.
- Dewar, M. J. S., Chatt, A. F., & Dunham, J. D. “The Bonding in Organometallic Compounds.” Journal of the Chemical Society, 1962.
References
- Royal Society. “Michael James Stanley Dewar (1918–1997).” Biographical Memoirs of Fellows of the Royal Society, 1998.
- Dewar, M. J. S. The Chemistry of Aromatic Compounds. Cambridge University Press, 1965.
- Woodward, R. B., “Historical Perspectives on Theoretical Chemistry.” Accounts of Chemical Research, 1994.