The Nobel Prize in Chemistry 1987

Charles J. Pedersen

The Supramolecular world

Introduction Nanosciences, nanotechnologies and supramolecular chemistry are today fields of universal scientific interest. Recent proof of this is demonstrated by the 2001 United States budget allocation for nanosciences through the “National Nanotechnology Initiative”. It amounts to some $500 million, which is more than double the amount allocated for the year 2000. In analogy, a significant number of internationally-recognized research laboratories here in Switzerland are also working in the areas of supramolecular chemistry and/or materials chemistry. Indeed, several research groups are currently well established in these areas, since they began their investigations when this field of science was first introduced. This places Swiss research teams at the forefront of these research domains. Exactly what are supramolecular functional materials? These are materials capable of fulfilling very specific tasks. Supramolecular functional materials are composed of supermolecules and as a consequence belong to the nanoworld. Invisible to the naked eye, their size scale is in the nanometer range. Nano, from the Greek word nanos meaning dwarf, is a prefix signifying one-billionth (1/1,000,000,000, 10-9). Let us make two comparisons: a chemical bound which links two atoms is generally, on the Angström unit of measurement, or one-tenth of a nanometer, and the diameter of a single strand of human hair is about 100,000 nanometers (0.1 mm). When did they become visible? The field covered by the term nanosciences is very wide, hence it is difficult to give a single starting point. As a consequence, it is perhaps advisable to speak in terms of two separate approaches namely, the nanotechnological and the supramolecular approach. The nanotechnological approach The nanotechnological approach is based on the individual manipulation of atoms and molecules in order to assemble complex structures with precision. For a many years, this type of approach was thought to be unfeasible. As recently as the 1950s, Erwin Schrödinger – winner of the Nobel prize for physics in 1933 – could not imagine that it would be possible to attempt an experiment on one electron, an atom or even a single molecule. Some years later he was proved wrong by another distinguished scientist, Richard P. Feynman, who was awarded the Nobel physics prize in 1965. Invited by the American Physical Society to its annual meeting on December 29, 1959, Feynman gave a memorable lecture entitled “There’s Plenty of Room at the Bottom”. He said: “The principles of physics, as far as I can see, do not speak against the possibility of manoeuvering things atom by atom.” The major limitation at that time was a lack of suitable technology. For this problem to be overcome, it was necessary to wait until the early 1980's for the invention of what is effectively scanning tunneling microscopy (STM), and atomic force microscopy (AFM). In 1986, the German Gerd Binning and the Swiss Heinrich Roher were jointly awarded the Nobel prize in physics for the invention of the scanning tunnel microscope. These instruments were initially conceived for the observation of atomic matter, but have since undergone modifications which have aided their applications in the manipulation and study of atoms. It is perhaps worth pointing out that as an experiment the acronym "IBM" was once written in 35 xenon atoms, carefully laid out over a single surface. The supramolecular approach In the supramolecular approach, the conception and realization of nanoscopic systems begins on the molecular scale. The strategies for realizing these systems are in general based on the principle of self-assembly. Molecules are linked together as supermolecules exploiting the non-covalent interactions nature has used for millions of years to assemble large functional biological molecules such as DNA and proteins (enzymes). Equally on speaks in terms of molecular recognition, applying the lock and key analogy to aid the understanding of this process. A receptor molecule (enzyme) can selectively recognize, bind and react with a complementary host (substrate) molecule. The first scientist to introduce this principle was the research chemist Emil Fischer, at the turn of the 20th century. While studying the reaction of an enzyme with its substrate, Fischer came to the conclusion that in order to recognize and then react, the 'shape' of a substrate molecule needs to be complementary with that of its receptor site. Rather like a key (substrate) with its corresponding lock (receptor). For these findings, he was awarded the Nobel prize in chemistry in 1902. It was not until nearly 100 years later that the full impact of Fischer's research was fully realized, when the chemist Jean-Marie Lehn began to work in the area he has since named as "supramolecular chemistry". Isolated molecules have properties which result from their molecular structure. However, a molecule is never totally isolated because it finds itself in a chemical environment with wich it is able to interact. From these interactions come new chemical and physical properties. The combination of molecular interactions is the concept on which supramolecular chemistry is based. Lehn received the Nobel chemistry prize in 1987 for his work on the "development and use of molecules with structure-specific interactions of high selectivity". To obtain supramolecular structures which are “made to measure”, or in other words, functional supramolecular structures, scientists are currently exploiting the possibilities of using molecular building blocks for the controlled self-assembly of larger supermolecules. Top-down, bottum-up The supramolecular and nanotechnological approaches are radically different from the approaches still generally adopted by the industry. The industrial approach is currently referred to as "top-down", or to put it another way, one starts on the largest scale and then reduces the size to develop increasingly smaller devices. In contrast however, the nanotechnological and the supramolecular approaches are referred to as being "bottom-up" - in other words one begins on the smallest (molecular) level and increases the size to move towards larger nanoscale dimensions. Two approaches, one single aim Although different, both approaches have important applications in the field of nanoscience and in the end lend themselves to a common goal namely, the conception and construction of "nanomachines" which will have a considerable impact on new technologies. The adventure is only just beginning, but the wildest dreams are already permissible. To quote Christine L. Peterson, president of the Foresight Institute: "If you're looking ahead long-term, and what you see looks like science fiction, it might be wrong. But if it doesn't look like science fiction, it's definitely wrong."

I was born in Pusan, Korea, on October 3, 1904. My father Brede Pedersen, was a Norwegian marine engineer who left home as a young man and shipped out as an engineer on a steam freighter to the Far East. He eventually arrived in Korea and joined the fleet of the Korean customs service, which was administered by the British. Later, he abandoned seafaring and became a mechanical engineer at the Unsan Mines in what is now the northwestern section of present-day North Korea.

My mother, Takino Yasui, was born in 1874 in Japan. She had accompanied her family to Korea when they decided to enter large-scale trade in soybeans and silkworms. They established headquarters not far from the Unsan Mines, where she met my father. I had a sister, Astrid, five years my senior, and an elder brother who died in childhood prior to my birth.

The Unsan Mines were an American gold and lumber concession, 500 square miles in area. Because the mines were administered by Americans, there was an effort to make life there as American as possible. English was the spoken language, and it was the language I learned as a child. Foreign language schools did not exist in Korea at that time and so at the age of 8 years I was sent to Japan to attend a convent school in Nagasaki. When I was 10 years old my mother took me to Yokohama, and I began my studies at St. Joseph College. St. Joseph's was a preparatory school run by a Roman Catholic religious order of priests and brothers called the Society of Mary, also known as the Marianists. There I received a general secondary education and took my first course in chemistry.

When it came time for university, I chose, with my father's encouragement, to study in America. I selected the University of Dayton because it was in Ohio were we had family and friends and because it too was run by the Society of Mary. After taking a bachelor's degree in chemical engineering at the University of Dayton, I went to the Massachusetts Institute of Technology where I obtained a master's degree in organic chemistry. I did not remain at MIT to take a Ph.D.; I was still being supported by my father, and I was anxious to begin working. In 1927, I obtained employment at the Du Pont Company in Wilmington, Delaware, through the good offices of Professor James F. Norris, a very prominent professor and my research advisor. At Du Pont, I was fortunate enough to be directed to research at Jackson Laboratory by William S. Calcott. I remained at Du Pont for my entire 42-year career as a chemist.

As a new scientist I was initially set to work on a series of typical problems, which I solved successfully. After a while, I began to search for oil-solvable precipitants for copper, and I found the first good metal deactivator for petroleum products. As a result of this work, I developed a great interest in the affects of various ligands on the catalytic properties of copper and the transition elements generally and worked in the field for several years.

I next expanded my interests in the oxidative degradation of the substrates I was working on, namely petroleum products and rubber. By the mid-1940s I was in full career, having established myself in the field of antioxidants and independent in terms of the problems I might choose. In 1947, I was appointed research associate, then the highest title that a Du Pont Company researcher could attain. Also at that time, I married Susan Ault and settled in the town of Salem, New Jersey, where I have lived ever since.

During the late '40s and '50s my scientific interests became more varied. I became interested in the photochemistry of some new phthalocyanine adducts and of quinoneimine dioxides. I developed polymerization initiators and even made some novel polymers. In 1960 I returned to investigations in coordination chemistry, and decided to study the effects of bi- and multidentate phenolic ligands on the catalytic properties of the vanadyl group, VO. In the course of these investigations one of my experiments yielded an unexpected small quantity of unknown white crystals which I eventually identified as dibenzo18-crown-6, first crown ether. The last nine years of my career were spent in the further study of crown ethers. I retired from Du Pont in 1969. During my retirement, I have pursued interests in fishing, gardening, bird study and poetry.

free web hits counter

This is my BrainyGoose:
United States, IL, Chicago, English, Italian, Genry, Male, 21-25, bodybulding, swiming.