Jean-Marie Lehn

Jean-Marie Lehn, born in 1939, French chemist and Nobel Prize winner. Lehn is a pioneer in the field of supramolecular chemistry, the study of organic compounds that form without the normal binding of shared electrons. His work has enabled researchers to understand the principles of molecular recognition (how specific molecules are able to recognize and react with each other). His discoveries have made it possible for scientists to mimic the components and behavior of enzymes and cells and thus create them artificially. For his work, Lehn was awarded the 1987 Nobel Prize in chemistry, which he shared with American chemists Charles J. Pedersen and Donald James Cram.

Born in Rosheim, France, Lehn received his Ph.D. degree in 1963 from the University of Strasbourg. After postdoctoral work at Harvard University, he returned to Strasbourg and became a full professor in 1970.

Lehn expanded on the work of cowinner Charles Pedersen, who discovered crown ethers in 1963. These crown-shaped compounds were the first to form bonds with the electrically charged atoms of alkali metals. Each crown ether is a ring of atoms with a hollow center (a receptor, or “host”), into which fits another atom (a “guest”). Before Lehn's contributions, crown ethers were flat, two-dimensional structures whose shape and size could not be determined. Therefore, scientists could not create receptors that would bind with specific atoms. Lehn reasoned that three-dimensional crown ethers would form much stronger bonds than their predecessors. To make the receptor molecule more rigid and expand the range of guests that it could bind with, Lehn created multiple layers of atoms with interconnected chains. He called these receptors cryptands because of their hollow, cryptlike shape. By varying the size and shape of the cryptands, he could bind specific molecules. In 1967 his first synthesized cryptand formed a bond to a potassium atom that was almost 10,000 times stronger than that demonstrated by Pedersen's crown ether. By the mid-1970s Lehn had developed hundreds of different receptors. He also discovered that when cryptands formed bonds, their structure was reorganized. This discovery formed the basis for what Lehn called supramolecular chemistry, since cryptand bonds were temporary and did not involve shared pairs of electrons like typical molecular bonds. His research was key to the understanding of molecular recognition, because all life depends on the ability of specific molecules to recognize and react with each other. Lehn was soon able to create molecules that imitate the properties and behavior of specific enzymes, and thus cause chemical reactions.

Lehn was made chair of chemistry at the Collège de France, Paris, in 1979 and began directing a research group in 1980. In addition to the Nobel Prize, he received the Bronze, Silver, Gold medals of the Centre National de la Recherche Scientifique in 1963, 1972, and 1981, respectively.