FLAX Jean-Marie

Linen, Jean-Marie (Lehn, Jean-Marie) (p. 1939) (France). Nobel Prize in Chemistry, 1987 (jointly with D. Kramov and C. Pedersen).

Born September 30, 1939 in Rozheyme, an old Alsatian town. Father, a baker, was fond of music, but because the city became organist. Mother contained a house and shop. He was the eldest of four sons and helped the mother in the store. In 11 years of age enrolled in secondary school, Collц?ge Freppel in Obernai, a small town 5 kilometers from Rozheyma. Music was his primary interest. Education in the school from 1950 to 1957 was a classic: Latin, Greek, German and English languages, French literature, and in the last year of study - philosophy. However, he became interested in chemistry. In July 1957, received a bachelor's degree in philosophy, and in September the same year - and in the natural sciences.

In Strasbourg University, he began with physics and chemistry. Organic chemistry has made such an impression on him that he began experimenting at home.

In October 1960, assumed the dissertation work involved the study of conformational and physico-chemical properties of triterpenes. He has adjusted well to the method of nuclear magnetic resonance, which helped him to further studies. This was the first key stage of its preparation.

After receiving his Ph.D. in July 1963, Len year internship in the laboratory of RB Woodward (Nobel Laureate, 1965) at Harvard University, where he took part in the outstanding predriyatii Woodward - synthesis of vitamin B12. A course of quantum mechanics and performed the first calculations by R. Hoffman, in 1964 and witnessed the first steps to establish the rules of the Woodward - Hoffman, R. Hoffman led to the Nobel Prize (1981).

After his return to Strasbourg Linen began to work independently in the field of physical organic chemistry, where he could combine the lessons learned in organic chemistry and quantum theory with the knowledge of physical methods. This marked the work of his laboratory, which was established after the appointment of Lena in 1966, Assistant Professor Department of Chemistry, University of Strasbourg, before 1970.

We had to take a decisive step - to find the point of application of accumulated scientific potential. Len interested in the processes occurring in the nervous system associated with the distribution of sodium and potassium ion on the cell membrane. He wanted to invent a chemical that would have affected the process of ion transport. The search for such compounds led to the creation of Lena cryptands, work on which began in October 1967.

In 1960 American Charles Pedersen randomly synthesized compounds called crown ether (crown - a crown) for the singularity of its structure - a blank inside and a movable ring of carbon atoms linked through a bridge oxygen atoms. By varying the size of the cycle, he found that crown ethers are able to selectively bind certain cations, placing them in the center of its 'crown'.

Its discovery has been extended Len and American Donald Kramov. Result of parallel efforts of three researchers was the synthesis of molecules that can selectively react with other molecules, just like enzymes are associated with other natural molecules.

Len expanded range crown ethers synthesized by Pedersen, but also created a new three-dimensional structures, called cryptands (from the Greek word meaning 'hidden'), which are also capable of selectively binding metal ions. Then he prepared a molecule which selectively interacts with acetylcholine, an important transmitter of nerve impulses. His work created a real pre-design of artificial enzymes, which may become effective their natural prototypes.

Crown ethers and cryptand seen first as a model system, capable of selective binding. It turned out that they can serve as models of biological and transport systems. Next, uncover the role of such compounds in modeling enzymes. Crown ethers were the first synthetic analogs of natural substances, implementing the transfer of alkali metal ions across the cell membrane. These vectors, called ionophore, operate on the same principle as crown ethers, although they have a more complicated structure. Natural vectors of cations belong to the so-called switchable ionophore. After going inside the cell, they are under the influence of certain influences thrown cation and quickly returned for the following. Speed of shuttle operations may reach several thousand per second, and often they occur against the concentration gradient.

Crown and cryptand as a substance that selectively bind certain ions are promising for medicine as a treatment for metallodefitsitnyh and metalloizbytochnyh states.

This area of research has expanded rapidly evolved into what Len later named by the term 'supramolecular chemistry'. Supramolecular chemistry studies the comprehensive aspects of molecular interactions 'guest' molecule with a 'master'. What is supramolecular chemistry? Len has identified it as the chemistry of intermolecular bonds that studies the association of two or more chemical species, as well as the structure of such associations. It lies outside the classical chemistry that studies the structure, properties and transformations of individual molecules. If the latter is the case, . mainly, . with reactions, . in which there are gaps and the formation of valence bonds, . is an object of study of supramolecular chemistry are almost exclusively non-valent interactions: hydrogen bond, . electrostatic interactions, . hydrophobic forces, . structure 'no connection',
. As is known, the energy of non-valent interactions of 1-2 orders of magnitude below the energy of valence bonds, however, if many of them, they lead to the formation of strong, yet flexible to change its structure associates. This combination of strength and capacity for rapid and reversible changes - a characteristic property of all biological molecular structures: nucleic acids, proteins, enzymes, vectors of particles.

Within a short period of supramolecular chemistry has developed into a vast field of knowledge, which includes several areas. The most important direction of research the last decade was the synthesis of compounds that can form complexes of type 'guest-host' with organic molecules. It is necessary for the separation and purification of organic substances, their activation, to create next-generation drugs and the myriad of other scientific and applied problems.

These studies were subsequently marked Lena Nobel Prize (1987, jointly with D. Kramov and C. Pedersen) 'for the development and application of molecules with structure-specific interactions of high selectivity'.

In 1976, Len started a new series of studies in the field of artificial photosynthesis, storing and chemical transformation of solar energy.

He was nominated for a professorship in early 1970 and became a full professor in October of that year. Two spring semester of 1972 and 1974 Linen - a visiting professor at Harvard University, lectured and directed research project. Cooperation continued until 1980.

In 1979 became the head of laboratory at the College de France. Main effort Lena is currently focused on the study of supramolecular self-organization, structure and properties of the 'programmed' supramolecular systems.

The scientific results Lena, who together with him for twenty years carried out nearly 150 researchers from over twenty countries, were presented in 400 publications and review articles.

For several years, Len worked as a visiting professor at other institutions: the Federal Institute of Technology in Zurich, the universities of Cambridge, Barcelona and Frankfurt.