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| Moses Gomberg | |
 Moses Gomberg, the father of radical chemistry
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| Born | 1866 |
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| Died | 1947 |
| Fields | chemistry |
| Institutions | University of Michigan |
| Alma mater | University of Michigan |
| Doctoral advisor | A. B. Prescott |
| Known for | radical chemistry |
Moses Gomberg (1866–1947) was a chemist.[1]
He was born in Elizabetgrad, Ukraine. In 1884, the family emigrated to Chicago to escape the pogroms following the assassination of Czar Alexander II. In 1886, Moses entered the University of Michigan, where he obtained his B.Sc in 1890 and his doctorate in 1894 under the supervision of A. B. Prescott. He remained at the University of Michigan for the rest of his life.
In 1896–1897 he took a year's leave to work as a postdoctoral researcher to work with Baeyer and Thiele in Munich and with Victor Meyer in Heidelberg, where he successfully prepared the long-elusive tetraphenylmethane.
During attempts to prepare the even more sterically congested hydrocarbon hexaphenylethane he correctly identified the triphenylmethyl radical, the first persistent radical to be discovered, and is thus known as the founder of radical chemistry. The work was later followed up by Wilhelm Schlenk. Gomberg was a mentor to Werner Emmanuel Bachmann who also carried on his work and together they discoverd the Gomberg-Bachmann reaction.[2]
Discovery of Persistent Radicals
Seeking to prepare hexaphenylethane (5) Gomberg attempted a Wurtz coupling of triphenylchloromethane (1). Elemental analysis of the resultant white crystalline solid however, uncovered discrepancies with the predicted molecular formula:
| calculated for (5) | found | |
|---|---|---|
| % Carbon | 93.83 | 87.93 |
| % Hydrogen | 6.17 | 6.04 |
Hypothesizing that (1) had combined with molecular oxygen to form the peroxide (4), Gomberg found that treatment of (1) with sodium peroxide was another means of synthesizing (4)
By preforming the reaction of triphenylchloromethane with zinc under an atmosphere of carbon dioxide Gomberg obtained the free radical (2) and hypothesized that it existed in equilibrium with its dimer hexaphenylethane (5) on the basis of molecular weight determination by freezing point depression, however this was later dis proven in favor of the quinoid dimer (3).[3]
External links
- Moses Gomberg in Ann Arbor Link
References
- ^ C. S. Schoepple and W. E. Bachmann (1947). "Moses Gomberg 1866-1947". Journal of the American Chemical Society 69: 2921–5, obituary. doi:.
- ^ M. Gomberg, W. E. Bachmann (1924). "The Synthesis of Biaryl Compounds by Means of the Diazo Reaction". Journal of the American Chemical Society 42: 2339–2343. doi:.
- ^ Gomberg, Journal of the American Chemical Society, (1900), 22, pg 757
