Linus Pauling is the best chemist of all time



    Linus Carl Pauling (Born February 28, 1901 in Portland, Oregon; † August 19, 1994 in Big Sur, California) was an American chemist of German descent. He received the Nobel Prize for Chemistry in 1954 and the Nobel Peace Prize in 1962 as a special award for his work against nuclear weapon tests, making him the only Nobel Prize winner in various categories alongside Marie Curie.

The first years

Pauling was born in Portland, Oregon. His father, Hermann Heinrich Wilhelm Pauling, a pharmacist whose parents immigrated from Germany, moved with his family from one city to another between 1903 and 1909 and returned with her to Portland last year. When the father died of a ruptured stomach ulcer in 1910, he left Linus' mother worried about Linus and two younger siblings.

Even as a child, Pauling was an insatiable reader. At one point his father even wrote a letter to a local newspaper asking for suggestions for other books to study. While in high school, his school friend, Lloyd Jeffress, had a small chemistry lab in his bedroom. The experiments with Jeffress inspired Pauling to later become a chemist.

Pauling continued doing chemical experiments through high school, borrowing most of the equipment and materials from an abandoned steel mill nearby where his grandfather worked as a night watchman.

College years

In 1917, Pauling enrolled at Oregon Agricultural College, now Oregon State University. He worked to finance his studies while attending a variety of lectures at the same time.

In his last two years in college, Pauling learned the work of Gilbert N. Lewis and Irving Langmuir, who studied the electronic structure of atoms and the chemical bonds that enable them to form molecules. He decided to focus his research on how the physical and chemical properties of substances are related to their atomic structure. So he co-founded a new science, quantum chemistry.

In his senior year in college, he met a fellow student Ava Helen Miller, and married her on June 17, 1923. The couple had three sons and a daughter.

In 1922 Pauling graduated from Oregon Agricultural College (OAC) and began postgraduate studies at Caltech in Pasadena, California. In his final research, he used X-ray diffraction to determine crystal structures. During his time at Caltech, he published seven papers on the crystal structures of minerals and received his doctorate in chemistry in 1925 summa cum laude.

Early scientific career

With the help of a Guggenheim scholarship, Pauling traveled to Europe in 1926 to continue studying with Arnold Sommerfeld in Munich, Niels Bohr in Copenhagen and Erwin Schrödinger in Zurich. All three worked in the new field of quantum mechanics. Pauling had already dealt with quantum mechanics during his time at the OAC and he now wanted to see whether they could help him understand his specialist area of ​​the electronic structure of atoms and molecules.

He devoted the two years in Europe entirely to his work and decided that this should be the future focus of his research. This made him one of the first scientists in the field of quantum chemistry. In 1927 he then took over an assistant professorship at Caltech for theoretical chemistry.

Pauling's career at Caltech began with five very productive years, during which he continued his X-ray studies on crystals and occupied himself with quantum mechanical calculations on atoms and molecules. During this time he published an estimated 50 articles. In 1929 he became Associate professor appointed and received a full professorship in 1930. In 1931 he received the Langmuir Prize from the American Society for Chemistry for the most significant work in the field of pure science by a person under the age of 30.

In the summer of 1930, Pauling traveled back to Europe to learn more about the use of electrons in diffraction studies, which were similar to his X-ray diffraction studies. Together with one of his students, L. O. Brockway, he built an electron diffraction instrument at Caltech and used it to study the molecular structure of a large number of chemical substances.

In 1932 he introduced the concept of electronegativity. Using the numerous properties of molecules, such as the energy required to break chemical bonds or the dipole moments of molecules, he determined numerical values ​​for most elements. He arranged these values ​​on a scale, the Pauling scale for electronegativity, with which the nature of bonds between atoms and molecules can be determined. (Another unit of measure for electronegativity was defined by Robert S. Mulliken, which is broadly the same as Paulings. However, the Pauling scale is more widely cited scientifically.)

Working on the nature of chemical bonds

In the 1930s, Pauling began to publish essays on the nature of chemical bonds, which were published in his famous 1939 book "The nature of the chemical bond"(Original title:"The Nature of the Chemical BondHe received the Nobel Prize in Chemistry in 1954 for his work in this area in particular, "for his research into the nature of chemical bonds and their application to elucidate the structures of complex substances".

Building on part of Pauling's work, he published the concept of hybridization. Usually the electrons of an atom are said to be on different orbitals (referred to as s, p etc.) located. It turned out, however, that to describe bonds in molecules, it is better to construct functions in which both parts take over properties from one another. The 2s- and the three 2p orbitals of a carbon atom can be combined to form four energetically equivalent orbitals (sp3 Hybrid orbitals called). In this way, the molecular bonds in carbon compounds such as methane can be represented in a suitable manner. The 2s orbital can also be combined with two 2p orbitals to create three equivalent orbitals (sp2 Hybrid orbitals called), which together with the remaining unhybridized 2p orbital are suitable for describing the molecular bonds of some unsaturated carbon compounds such as ethene. The molecular bonds of other types of molecules can also be explained by other hybridization schemes.

Another area of ​​his research was the relationship between an ionic bond, in which electrons are transferred between atoms, and a covalent bond, in which the electrons are evenly distributed between atoms. Pauling showed that both types of attachment are merely extremes between which most common attachments lie. Pauling's concept of electronegativity was particularly useful here, because the difference in electronegativity between two atoms is the most reliable indicator of the degree of ionization of the bond.

The third of his research topics, the Pauling under the umbrella of Nature of the chemical bond investigated was the enumeration of the structures of aromatics, especially the prototype benzene. According to today's understanding, the most precise description of benzene was made by the German chemist Friedrich Kekulé. He viewed the connection as a constant change between two structures, both with alternating single and double bonds, each with the double bond at the point where the single bond of the other structure is located. With a suitable description based on quantum mechanics, Pauling showed that there is an intermediate structure that contains aspects of both. The structure represented more of a superposition of the two structures than a quick change between them. The term resonance or mesomerism was only given to this phenomenon later. In a certain way, the phenomenon is similar to that of hybridization described earlier in that it also involves more than one electronic structure to achieve an intermediate result.

Working on biological molecules

In the mid-1930s, Pauling decided to open up new areas of interest. In his early years he mentioned his lack of interest in the study of molecules with biological significance. But as Caltech began to focus more and more on biology, Pauling began to work with such great biologists as Thomas Hunt Morgan, Theodosius Dobzhansky, Calvin Bridges and Alfred H. Sturtevant, as he developed an interest in biological molecules.

His first work in this area was on the structure of hemoglobin. He was able to demonstrate that the hemoglobin molecule changes its structure when it binds or releases an oxygen atom. As a result of these investigations, he decided to make a thorough study of the structures of proteins in general. To do this, he returned to his old method of X-ray diffraction. Unfortunately, protein molecules are much less suitable for this technique than crystalline minerals. The best X-ray photographs of proteins were made by the British crystallographer William Astbury in the 1930s. But when Pauling tried in 1937 to take part in Astbury's investigations, he was unsuccessful.

It took Pauling eleven years to explain the problem: while his mathematical analysis was correct, Astbury's images were captured in such a way that they were tilted to their expected positions. Pauling formulated a model of the structure of hemoglobin, in which the atoms are arranged in a helix, and transferred this idea to proteins in general. The double helix that James Watson and Francis Crick postulated for deoxyribonucleic acid (DNA) can also be traced back to this helix structure. Pauling also came very close to this structure. Although his assumed structure of DNA was not entirely correct, many familiar with his work believe that Pauling would soon have come to the same conclusion as Watson and Crick had it not been for him.

Pauling also worked on enzyme reactions and showed that sickle cell anemia can be traced back to a change in a single amino acid in hemoglobin. As a result of this work he dealt with the structure of antibodies and was involved in the development of the first synthetic antibodies in 1942.

Political commitment

The Second World War made a fundamental change in Pauling's life. Up until this point he was fairly apolitical, but as a result of his experience he became involved as a peace activist. In 1946 he became a member of the Emergency Committee of Atomic Scientists, chaired by Albert Einstein, who wanted to educate the public about the dangers posed by nuclear weapons. Because of his political commitment, the US State Department refused him a visa when he was invited to speak at a scientific conference in London in 1952. This conference was supposed to be about the helix structure of proteins. Had he been able to attend this conference, he might have discovered the true structure of DNA sooner. It was not until shortly before the ceremony to award the Nobel Prize in 1954 that he received a passport again.

In 1957 Pauling began a petition campaign with the biologist Barry Commoner. He had investigated the distribution of radioactive strontium-90 in the milk teeth of children across North America and had come to the conclusion that the above-ground nuclear tests pose major health risks from the radioactive fallout. In 1958, Pauling and his wife submitted a United Nations petition to the US government, which was signed by more than 11,000 scientists, calling for an end to nuclear testing. The public pressure that followed led to a moratorium and test ban, which John F. Kennedy and Nikita Khrushchev signed in 1963. On the day the treaty came into force, the Nobel Prize Committee Pauling awarded the Nobel Peace Prize: "Linus Carl Pauling has always campaigned relentlessly since 1946, not only against nuclear weapon tests, not only against the spread of nuclear weapons, also not against their use , but against all warfare as a measure to resolve international conflicts. "

Many of Pauling's critics, including many scientists who acknowledge his contribution to chemistry, disagree with his political views and saw him as a naive advocate of Russian communism. He was quoted by an internal Senate security committee which called him "the most important scientist in practically every activity of the communist peace offensive in this country". An extraordinary headline of the Life Magazine characterized his 1962 Nobel Peace Prize as a "strange denigration from Norway".

The work of the last few years

Pauling's work in later years has repeatedly caused controversy and has repeatedly been dismissed as a pseudoscientific hoax. In 1966, at the age of 65, he began adopting the ideas of the biochemist Irwin Stone, who saw large doses of vitamin C as a cure for colds. Pauling went even further and believed that vitamin C could also prevent cancer. He himself consumed about 18 grams of vitamin C every day. While most scientists do not hold these assumptions valid, there are a small number who believe that it is one of the cases when natural substances in the body can prevent disease. This led to orthomolecular medicine and when Pauling retired in 1974, he and others founded the Institute for Orthomolecular Medicine in Palo Alto, California, which is now the Linus Pauling Institute of Science and Medicine. Today the institute abandoned massive doses of vitamin C. Pauling himself, on the other hand, took action against almost every medical problem with bold formulations ("Vitamins, Vitamins!"). As a full member and honorary president, Linus Pauling was actively involved in building up the International Academy of Science together with Nobel Prize winner Alexander Michailowitsch Prokhorov (Russia) and the psychosomaticist Yujiro Ikemi (Japan).

Linus Pauling and Marie Curie are the only two people to have received a Nobel Prize in more than one area, with Linus Pauling being the only one to have received it twice without having to share it with anyone else.

The double doctorate chemistry professor Pauling died at the old age of 93 years on his farm in Big Sur, California of prostate cancer, which is particularly common for this age. Up to this old age, Prof. Pauling was vigorous and mentally active. He attributed his vitality and his old age to his supposedly healthy lifestyle and the consumption of very high vitamin doses. Pauling liked to drink vodka, avoided sugar, white bread and cigarettes and increased the dose of his vitamins with age.

Fonts (selection)

Articles in specialist publications

  • Alfred E. Mirsky, Linus Pauling: On The Structure of Native, Denatured, and Coagulated Proteins. in: Proceedings of the National Academy of Sciences (PNAS). Washington DC 22 (1936), No. 7 (July), 439-447. ISSN 0027-8424
  • Linus Pauling, Carl Niemann: The Structure of Proteins. in: Journal of the American Chemical Society Washington DC 61 (1939) 1860-1867. ISSN 0002-7863
  • Linus Pauling, Dan H. Campbell, David Pressman: The Nature of the Forces Between Antigen and Antibody and of the Precipitation Reaction. in: Physiological Reviews. Bethesda Md 23 (1943), No. 3 (July), 203-219. ISSN 0031-9333
  • Linus Pauling, Harvey A. Itano, S. J. Singer, Ibert C. Wells: Sickle Cell Anemia, A Molecular Disease. in: Science. Washington DC 110 (1949), No. 2865 (Nov. 25), 543-548. ISSN 0036-8075
  • Linus Pauling, Robert B. Corey: The Polypeptide-Chain Configuration in Hemoglobin and Other Globular Proteins. in: Proceedings of the National Academy of Sciences (PNAS). Washington DC 37 (1951) 5 (May), 282-285. ISSN 0027-8424
  • Linus Pauling, Robert B. Corey: A Proposed Structure for the Nucleic Acids. in: Proceedings of the National Academy of Sciences (PNAS). Washington DC 39.1953, 84-97. ISSN 0027-8424
  • Linus Pauling: Vitamins C papers. in: Science. Washington DC 243 (1989), No. 4898, p. 1535. ISSN 0036-8075
  • Linus Pauling: How my interest in proteins developed. in: Protein science (PS). Laboratory Press, Cold Spring Harbor 2.1993, 6, 1060-1063. ISSN 0961-8368
  • Linus Pauling: My first five years in science. in: Nature. London 371 (1994), No. 6492, p. 10. ISSN 0028-0836

(A selection of publications as reprints in PDF format can be found here)

Textbooks

  • Linus Pauling: The nature of the chemical bond. Trans. V. H. Noller.Verlag Chemie, Weinheim 1968, 1976. ISBN 3-527-25217-7
  • Linus Pauling: The Nature of the Chemical Bond and the Structure of Molecules and Crystals - An Introduction to Modern Structural Chemistry. Cornell University Press, Ithaca NY 1939, 1960. (Orig.)
  • Linus Pauling: Basics of chemistry. Trans. V. Friedrich G. Helfferich. Verlag Chemie, Weinheim 1956, 1973. ISBN 3527253920
  • Linus Pauling: General Chemistry. W. H. Freeman, San Francisco 1949, 1970, Dover Publications, New York 1988. (Orig., Repr.) ISBN 0-486-65622-5
  • Linus Pauling: Vitamin C and the common cold. Trans. V. Friedrich G. Helfferich. Verlag Chemie, Weinheim 1972. ISBN 3-527-25458-7
  • Linus Pauling: Vitamin C and the Common Cold. W. H. Freeman, San Francisco 1970. (Orig.)
  • Linus Pauling, E. Bright Wilson Jr:Introduction to Quantum Mechanics with Applications to Chemistry. McGraw-Hill, New York 1935, Dover Publications, New York 1963, 1985. ISBN 0486648710
  • Linus Pauling: The vitamin program, Goldmann Verlag, Munich 1990, 1992, ISBN 3-442-13648-2

Political Writings

  • Linus Pauling: Life or death in the atomic age. Translated by Hildburg Braun. Sensen-Verl., Vienna 1960, Aufbau-Verl., Berlin 1964.
  • Linus Pauling: New morals and international law. Union-Verl. VOB, Berlin 1970.

literature

  • A. Serafini: Linus Pauling - A Man and His Science. Paragon House, New York NY 1989, 1991. ISBN 0-913729-88-4
  • Barbara Marinacci (Ed): Linus Pauling in His Own Words. Selections from His Writings, Speeches, and Interviews. Touchstone Books. Simon & Schuster, New York 1995. ISBN 0684807491
  • Bernhard Kupfer: Lexicon of Nobel Prize Winners. Patmos, Düsseldorf 2001. ISBN 3-491-72451-1
  • The 100 of the century. Natural scientist. Rowohlt, Reinbek near Hamburg 1994, p.150f. ISBN 3-499-16451-5
  • Ramin Rowghani: How do you live longer and feel better? Pauling's research results and their significance for the present. in: People and media. Kudamm courier. Journal for cultural and communication psychology. Linde-Kultur-Verlag, Berlin 2004 (also online).

Categories: Nobel Prize Winners in Chemistry | Theoretical Chemist | Physical chemist | Chemist (20th century) | Crystallography