I was born on September 30 1939 in Rosheim, a small medieval city of Alsace in France. My father, Pierre Lehn, then a baker, was very interested in music, played the piano and the organ and became later, having given up the bakery, the organist of the city. My mother Marie kept the house and the shop. I was the eldest of four sons and helped out in the shop with my first brother. I grew up in Rosheim during the years of the second world war, went to primary school after the war and, at age eleven, I entered high school, the Collège Freppel, located in Obernai, a small city about five kilometers from Rosheim. During these years I began to play the piano and the organ, and with time music has become my major interest outside science. My high school studies from 1950 to 1957 were in classics, with Latin, Greek, German, and English languages, French literature and, during the last year, philosophy, on which I was especially keen. However, I also became interested in sciences, especially chemistry, so that I obtained the baccalauréat in Philosophy in July 1957 and in Experimental Sciences in September of the same year.

I envisaged to study philosophy at the University of Strasbourg, but being still undecided, I began with first year courses in physical, chemical and natural sciences (SPCN). During this year 1957/58, I was impressed by the coherent and rigorous structure of organic chemistry. I was particularly receptive to the experimental power of organic chemistry, which was able to convert at will, it seemed, complicated substances into one another following well defined rules and routes. I bought myself compounds and glassware and began performing laboratory practice experiments at my parents home. The seed was sown, so that when, the next year, I followed the stimulating lectures of a newly appointed young professor, Guy Ourisson, it became clear to me that I wanted to do research in organic chemistry.

After having obtained the degree of Licencié-ès-Sciences (Bachelor), I entered Ourisson’s laboratory in October of 1960, as a junior member of the Centre National de la Recherche Scientifique in order to work towards a Ph.D. degree. This was the first decisive stage of my training. My work was concerned with conformational and physico-chemical properties of triterpenes. Being in charge of our first NMR spectrometer, I was led to penetrate more deeply into the arcanes of this very powerful physical method; this was to be of much importance for later studies. My first scientific paper in 1961 reported an additivity rule for substituent induced shifts of proton NMR signals in steroid derivatives.

Having obtained my degree of Docteur ès Sciences (Ph.D.) in June of 1963, I spent a year in the laboratory of Robert Burns Woodward at Harvard University, where I took part in the immense enterprise of the total synthesis of Vitamin B₁₂. This was the second decisive stage of my life as a researcher. I also followed a course in quantum mechanics and performed my first computations with Roald Hoffmann. I had the chance to witness in 1964 the initial stages of what was to become the Woodward-Hoffmann rules.

After my return to Strasbourg, I began to work in the area of physical organic chemistry, where I could combine the knowledge acquired in organic chemistry, in quantum theory and on physical methods. It was clear that, in order to be able to better analyze physical properties of molecules, a powerful means was to synthesize compounds that would be especially well suited for revealing a given property and its relationships to structure. This orientation characterized the years 1965- 1970 of my activities and of my young laboratory, newly established after my appointment in 1966 as maître de conférences (assistant professor) at the Chemistry Department of the University of Strasbourg. Our main research topics were concerned with NMR studies of conformational rate processes, nitrogen inversion, quadrupolar relaxation, molecular motions and liquid structure, as well as ab initio quantum chemical computations of inversion barriers, of electronic structures and later on, of stereoelectronic effects.

While pursuing these projects, my interest for the processes occurring in the nervous system (stemming diffusely from the first year courses in biology as well as from my earlier inclination towards philosophy), led me to wonder how a chemist might contribute to their study. The electrical phenomena in nerve cells depend on sodium and potassium ion distributions across membranes. A possible entry into the field was to try to affect the processes which allow ion transport and gradients to be established. I related this to the then very recent observations that natural antibiotics were able to make membranes permeable to cations. It thus appeared possible to devise chemical substances that would display similar properties. The search for such compounds led to the design of cation cryptates, on which work was started in October 1967. This area of research expanded rapidly, taking up eventually the major part of my group and developing into what I later on termed “supramolecular chemistry”. Organic, inorganic and biological aspects of this field were explored and investigations are continuing. In 1976 another line of research was started in the area of artificial photosynthesis and the storage and chemical conversion of solar energy; it was first concerned with the photoly is of water and later with the photoreduction of carbon dioxide.

I was promoted associate professor in early 1970 and full professor in October of the same year. I spent the two spring semesters of 1972 and 1974 as visiting professor at Harvard University giving lectures and directing a research project. This relationship extended on a loose basis to 1980. In 1979, I was elected to the chair of “Chimie des Interactions Moléculaires” at the Collège de France in Paris. I took over the chemistry laboratory of the Collège de France when Alain Horeau retired in 1980 and thereafter divided my time between the two laboratories in Strasbourg and in Paris, a situation continuing up to the present. New lines of research developed, in particular on combining the recognition, transport and catalytic properties displayed by supramolecular species with the features of organized phases, the long range goal being to design and realize “molecular devices”, molecular components that would eventually be able to perform signal and information processing at the molecular level. A major research effort is presently also devoted to supramolecular self-organisation, the design and properties of “programmed” supramolecular systems.

The scientific work, performed over twenty years with about 150 collaborators from over twenty countries, has been described in about 400 publications and review papers. Over the years I was visiting professor at other institutions, the E.T.H. in Zürich, the Universities of Cambridge, Barcelona, Frankfurt.

In 1965 I married Sylvie Lederer and we have two sons, David (born 1966) and Mathias (born 1969).

This autobiography/biography was written at the time of the award and later published in the book series Les Prix Nobel/ Nobel Lectures/The Nobel Prizes. The information is sometimes updated with an addendum submitted by the Laureate.

Addendum, January 2006

Research Activities – Update
Over the years, the studies in supramolecular chemistry in my laboratory at the Université Louis Pasteur in Strasbourg extended into a broad new area at the interface of chemistry with biology: self-organization processes, making use of molecular recognition to control and direct the spontaneous formation of functional architectures of high complexity.

Realizing that recognition implies information, led to the concepts of molecular programming and of programmed chemical systems, undergoing self-organization on the basis of the molecular storage of information and its processing at the supramolecular level through algorithms defined by the specific features of the intermolecular interaction patterns involved in the system considered.

These investigations provide steps towards a progressive understanding of the passage from condensed matter to organized matter, of which living organisms represent the highest expression. They seek to lay the chemical, molecular and supramolecular foundations on which the highly complex events of biological self-organization are built and to provide means for analyzing their mechanism as well as for acting on them.

A variety of chemical self-organizing systems of either organic or inorganic nature were designed and studied, leading to the generation of various organic and inorganic supramolecular architectures from molecular components assembled respectively through hydrogen-bonding and ligand-metal ion recognition processes, such as – the “helicates“, double, triple, and circular inorganic helices, – multicompartmental nanocylinders, –”grid-type” entities, ordered polymetallic arrays presenting a range of intriguing physico-chemical properties (multiple redox states, spin crossover magnetism, etc.).

The combination of molecular “softwares” specific for the assembly of different architectures into a single programme gave rise to the concept of multiple expression of molecular information, whereby the supramolecular processing of the information by different recognition algorithms generates different outputs, in a one code/several products mode.

Introducing the concepts and results of supramolecular chemistry into materials science, led to the emergence and the development of supramolecular polymer chemistry, as a new area in polymer chemistry.

On the other hand, the elaboration of approaches towards the generation of architectures for nanostructured materials stresses the broad impact that self-organization may have in nanoscience and nanotechnology, by allowing the potential replacement of tedious and expensive fabrication and addressing procedures by powerful self-fabrication and self-addressing processes.

Starting in the early 1990s, a novel line of research was initiated. It developed from the implementation of a basic feature of supramolecular chemistry, the fact that it is by essence a dynamic chemistry with respect to the constitution of its entities. Indeed, a supramolecular entity may continuously exchange, incorporate/decorporate and rearrange its molecular components, and thus continuously modify its constitution as a consequence of the inherent reversibility of the non-covalent interactions that connect these components. Importing such dynamic features into molecular chemistry requires the intentional introduction of reversible covalent bonds into molecules, so as to confer upon them a plasticity in constitution, characteristic of supramolecular chemistry.

These considerations led to the definition of a general concept, covering molecular as well as supramolecular chemistry, that of constitutional dynamic chemistry (CDC).

Thus, dynamic chemistry, that is usually considered to concern either reaction dynamics or motional dynamics, is extended to the very constitution of chemical entities itself. CDC may have a profound impact on numerous areas of investigation from drug discovery, to materials science and to nanotechnology.

On the molecular/covalent level, CDC covers dynamic combinatorial chemistry (DCC), an approach that, in contrast to classical “static” combinatorial chemistry based on vast collections of prefabricated molecules, implements dynamic libraries whose constituents undergo continuous interconversion by recombination of their building blocks through reversible chemical reactions. Addition of a target molecule to the dynamic set creates a driving force that favours the formation of the best-binding constituent – a self-screening process operating on the basis of molecular recognition between the partners. The application of this methodology to biological systems has allowed the generation of biologically active substances, in particular enzyme inhibitors (carbonic anhydrase, acetylcholine esterase). It is capable, in principle, of accelerating the identification of lead compounds for drug discovery.

In the area of materials science, CDC has been implemented in the development of dynamic polymers, dynamers, reversible polymers of molecular as well as supramolecular nature, such as dynamic polyamides. The potential uses of dynamers resulting from their reversibility have been explored towards applications in areas such as degradable materials and controlled release of active substances through collaborations with companies, leading to a number of patents.

CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization by selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation in a darwinistic fashion.

By extending its characteristic features information/programmability, dynamics/reversibility, constitution/structural diversity, supramolecular chemistry is thus impacting molecular chemistry, leading towards the emergence of adaptive and evolutive chemistry.

The research activities of my laboratory at the Collège de France in Paris covered several topics different from but related to those pursued in Strasbourg: – molecular recognition of nucleic acid features by macrocycles containing intercaland groups; – extension of transport processes towards gene transfer through the design of efficient cationic vectors; – implementation of molecular recognition in lipid vesicles, leading to selective aggregation and fusion processes between vesicles doped with complementary recognition groups (recosomes) interacting through hydrogen bonding or metal coordination. Reversible photochemical reactions were used for introducing switching capability into molecular wires and for developing write/read/erase processes for information storage.

In 1998, I set up and directed a research group at the Nanotechnology Institute newly created in the Research Center of Karlsruhe. This allowed to offer to former post-doctoral coworkers the opportunity to develop and to progressively set up independent research activities in nanoscience and nanotechnology.

In the years since 1987, I also had the occasion to engage in activities of general interest. They were as diverse as being Founding Chairman of a new chemical journal “Chemistry, a European Journal”, created in 1995 and truly European as it is now co-owned by 14 European chemical societies. It also gave the starting impetus to a range of European journals (European Journal of Organic Chemistry, European Journal of Inorganic Chemistry, ChemBioChem, ChemPhysChem) that resulted from the termination of national journals of long tradition (such as Berichte der Deutschen Chemischen Gesellschaft, Liebigs Annalen der Chemie, Bulletin de la Société Chimique de France, Gazzetta Chimica Italiana, Recueil des Travaux Chimiques des Pays Bas, Bulletin des Sociétés Chimiques Belges), an all too rare manifestation of European spirit and supranationality bridging historical divides!

A notable activity was the scientific planning of a novel institute ISIS (Institut de Science et d’Ingénierie Supramoléculaires) inaugurated in December 2002, housed in an attractive new building generously financed by the local authorities and provided in equipment and positions thanks to the strong support of the French Ministery of Research. It was possible to assemble a number of high level senior scientists from various countries, promising junior scientists as well as research laboratories from companies in a very stimulating atmosphere.

I have over the years been involved in a number of public and private boards and committees as well as participated in several start-up companies.

Finally, as president of the non-governmental organization IOCD (International Organization for Chemical Sciences in Development), I have tried, with a group of highly dedicated colleagues, to contribute to helping chemists in developing countries.

The scientific work performed now over forty years with about 300 collaborators from over twenty countries has been described in about 800 publications and review papers as well as two books.

This autobiography/biography was written at the time of the award and later published in the book series Les Prix Nobel/ Nobel Lectures/The Nobel Prizes. The information is sometimes updated with an addendum submitted by the Laureate.