Lehn, Jean-Marie (1939– )

French chemist who demonstrated for the first time how metal ions could be made to exist in a non-planar structure, tightly bound into the cavity of a crown ether molecule, explaining a possible mechanism for the transfer of metal ions across biological membranes. He was awarded the Nobel Prize for Chemistry in 1987 with Charles Pedersen and Donald Cram for their work on molecules with highly selective structure-specific interactions.

Lehn worked on the structures of crown ethers, which had just been discovered by his contemporary Pedersen and were found to have strong affinities for metal ions. Lehn demonstrated that if two nitrogen atoms replaced oxygen atoms in the ‘crown’, a three-dimensional structure could be made by connecting two crowns – which Lehn called a ‘cryptand’.

Lehn was then able to produce cryptands that could bind to molecules such as neurotransmitters. His research expanded the branch of organic chemistry known as host-guest chemistry and introduced the concept of supramolecules.

Lehn was born in Rosheim, France, and went to Strasbourg University. He studied the terpenes, and then at Harvard, Lehn worked on vitamin B12 synthesis. He moved between the two universities, gained a professorship, and finally settled at the College de France, Paris, where he held a chair in chemistry from 1979.