Manfred Eigen

Manfred Eigen
(1927)

German physicist who was corecipient, with R.G.W. Norrish and George Porter, of the 1967 Nobel Prize for Chemistry for work on extremely rapid chemical reactions. By perturbing a system at equilibrium, then following its return to equilibrium via a "relaxation" process, Eigen was able to avoid the time required to mix reagents, and thus study the kinetics of very fast reactions. He found, for example, that the reaction H+ + OH- > H2O occurs at every encounter between the solvated ions. Using similar methods, Eigen measured rates of proton transfer in organic acids and bases, and extended the method to complex sequences of biological reactions.
Eigen was born in Bochum, Germany, received the Ph.D. in physics and chemistry at the University of Gottingen (1950) and became Professor and Director of the Max-Planck Institute for Biophysical Chemistry there.

Eigen was able to study many extremely fast chemical reactions by a variety of methods that he introduced and which are called relaxation techniques. These involve the application of bursts of energy to a solution that briefly destroy its equilibrium before a new equilibrium is reached. Eigen studied what happened to the solution in the extremely brief interval between the two equilibria by means of absorption spectroscopy. Among specific topics thus investigated were the rate of hydrogen ion formation through dissociation in water, diffusion-controlled protolytic reactions, and the kinetics of keto-enol tautomerism.