George A. Olah

George A. Olah, born in 1927, Hungarian-American chemist and Nobel Prize winner. Olah developed acids that stabilize reactive intermediates, substances formed during chemical reactions that vanish in the split second before the reaction is completed. Before Olah’s method, these intermediates could not be isolated or studied. For this important breakthrough, he was awarded the 1994 Nobel Prize in chemistry.

Born in Budapest, Hungary, Olah received his Ph.D. degree in organic chemistry from the Technical University of Budapest in 1949. He emigrated to the United States in 1957 to work as a research scientist for Dow Chemical Company. In 1965 he became professor of chemistry at Case Western Reserve University in Cleveland, Ohio. He moved to the University of Southern California (USC) in 1977, and in 1983 was appointed Loker Distinguished Professor of Organic Chemistry. Olah became director of the Loker Hydrogen Research Institute in 1991.

Scientists had developed theories about reactive intermediates without ever having seen them. These theories were needed to explain how the molecular shape of reactants (the original substance entering a reaction) could be transformed into the molecular shape of products (the substance produced by the reaction). There was little agreement about the specifics of intermediates, and some scientists doubted their existence. The main problem was that intermediates are highly unstable. They react immediately with any substance they touch, changing their structure instantly. Therefore, it was considered useless to analyze the intermediates, even if they could somehow be trapped or harnessed for observation. For example, one class of intermediates—carbocations—pick up an extra hydrogen atom when combined with an acid catalyst. They immediately react with any surrounding substance by trying to donate the atom to another molecule or by stealing necessary electrons from other atoms.

Olah realized that if he could outsmart carbocations—that is, if he could find a stronger substance that reacts the same way—he could keep the carbocations from reacting, and thus stabilize them for observation. He decided to use a highly potent substance known as a superacid, which contains both a positive hydrogen atom and a negative atom that has a shortage of electrons. This shortage causes the superacid to seek electrons or give away its hydrogen atom. As Olah predicted, in reaction the stronger superacid gave extra hydrogen to, or stole electrons from, the weaker carbocation. This stabilized the intermediates so that they could not react further. Olah was then able to study the intermediates and determine their structure using nuclear magnetic resonance (NMR) and other techniques.

After his discovery, Olah helped to develop a number of new superacids that are used in both industry and research to stabilize the reactive intermediates of important reactions.