Linus (Carl) Pauling

Pauling pioneered the application of quantum mechanics to chemistry (quantum mechanics can, in principle, describe all of chemistry and molecular biology), and in 1954 was awarded the Nobel Prize in chemistry for his work describing the nature of chemical bonds. Pauling is noted as a versatile scholar for his expertise in inorganic chemistry, organic chemistry, metallurgy, immunology, anesthesiology, psychology, debate, radioactive decay, and the aftermath of nuclear weapons, in addition to quantum mechanics and molecular biology.

Pauling received the Nobel Peace Prize in 1962 for his campaign against above-ground nuclear testing, and is the only person to win two unshared Nobel prizes - that is, none of the prizes were shared with another recipient/s.

Early life

Pauling was born in Portland, Oregon to Herman Henry William Pauling (1876-1910) of Concordia, Missouri; Herman died in 1910 of a perforated ulcer, and Isabelle was left to care for Linus and two younger siblings: Pauline Pauling (1901-2003) who married Thomas Joseph Ney (1881-1963) of Millville, New Jersey;

Pauling was a voracious reader as a child, and at one point his father wrote a letter to a local paper inviting suggestions of additional books that would occupy his time. A friend, Lloyd Jeffress, had a small chemistry laboratory in his bedroom when Pauling was in grammar school, and Jeffress' laboratory experiments inspired Pauling to plan to become a chemical engineer.

In high school, Pauling continued to experiment in chemistry, borrowing much of the equipment and materials from an abandoned steel company near which his grandfather worked as a night watchman.

Pauling failed to take some required American history courses and did not qualify for his high school diploma. 1923) Son: Linus Carl Pauling, Jr. 1931) Daughter: Linda Helen Pauling (b. 1937)

College and university

In 1917, Pauling entered the Oregon Agricultural College (OAC) in Corvallis, now Oregon State University. After his second year, he planned to take a job in Portland to help support his mother, but the college offered him a position teaching quantitative analysis (a course Pauling had just finished taking as a student).

In his last two years at OAC, Pauling became aware of the work of Gilbert N.

In 1922, Pauling graduated from OAC and went to graduate school at the California Institute of Technology ("Caltech") in Pasadena, California under the guidance of Roscoe G.

Marriage

In his senior years Linus Pauling taught junior classes in "Chemistry for Home Economic Majors" .

Early scientific career

Pauling later traveled to Europe on a Guggenheim Fellowship to study under German physicist Arnold Sommerfeld in Munich, Danish physicist Niels Bohr in Copenhagen, and Austrian physicist Erwin Schrödinger in Zürich. While he was studying at the Oregon Agricultural College, Pauling was first exposed to the idea of quantum theory and quantum mechanics. In Europe, Pauling was also exposed to one of the first quantum mechanical analyses of bonding in the hydrogen molecule, done by Walter Heitler and Fritz London. Pauling devoted the two years of his European trip to this work and decided to make this the focus of his future research.

Pauling began his faculty career at Caltech with a very productive five years, both continuing with his X-ray crystal studies and performing quantum mechanical calculations on atoms and molecules. He published approximately fifty papers in those five years and created five rules now known as Pauling's Rules. By 1931, the American Chemical Society awarded Pauling the Langmuir Prize for the most significant work in pure science by a person 30 years of age or younger. In 1932, Pauling published what he regarded as his most important paper, in which he first laid out the concept of hybridization of atomic orbitals and analyzed the tetravalency of the carbon atom.

At Caltech, Pauling struck a close friendship with theoretical physicist Robert Oppenheimer, who was spending part of his research and teaching schedule away from Berkeley at Caltech every year. However, this relationship soured when Pauling began to suspect that Oppenheimer was probably becoming too close to Pauling's wife, Ava Helen. Once, when Pauling was at work, Oppenheimer had come to their place and blurted out an invitation to Ava Helen to join him on a tryst to Mexico. This, and her apparent nonchalance about the incident, disquieted him, and he immediately cut off his relationship with the Berkeley professor, leading to a coolness between them that would last their lives, although Oppenheimer did invite Pauling to be the head of the Chemistry Division of the atomic bomb project.

In the summer of 1930, Pauling made another European trip, learning about the use of electrons in diffraction studies similar to the ones he had performed with X-rays.

Linus Pauling introduced the concept of electronegativity in 1932. Using the various properties of molecules, such as the energy required to break bonds and the dipole moments of molecules, he established a scale and an associated numerical value for most of the elements, the Pauling Electronegativity Scale, which is useful in predicting the nature of bonds between atoms in molecules.

Work on the nature of the chemical bond

In the 1930s he began publishing papers on the nature of the chemical bond, leading to his famous textbook on the subject published in 1939. Pauling summarized his work on the chemical bond in The Nature of the Chemical Bond, one of the most influential chemistry books ever published.

Part of Pauling's work on the nature of the chemical bond led to his introduction of the concept of orbital hybridization. Pauling showed that these were merely extremes, between which most actual cases of bonding fall.

The third of the topics that Pauling attacked under the overall heading of "the nature of the chemical bond" was the accounting of the structure of aromatic hydrocarbons, particularly the prototype, benzene. Pauling showed that a proper description based on quantum mechanics was an intermediate structure containing some aspects of each.

Work on structure of the atomic nucleus

On September 16, 1952, Linus Pauling opened a new research notebook with these words "I have decided to attack the problem of the structure of nuclei" (see his actual notes at Oregon State Special Collections). On October 15, 1965, Pauling published his Close-Packed Spheron Model of the atomic nucleus in two well respected journals, Science, and Proc. For nearly three decades, until his death in 1994, Pauling published numerous papers on his spheron cluster model.

No modern text books on nuclear physics discuss the Pauling Spheron Model of the Atomic Nucleus, yet it provides a unique perspective, well published in the leading journals of science, on how fundamental "clusters of nucleons" can form shell structure in agreement with recognized theory of quantum mechanics. Pauling was well versed in quantum mechanics--he coauthored one of the first textbooks on the subject (Introduction to Quantum Mechanics with Applications to Chemistry by Linus Pauling, E.

Work on biological molecules

In the mid-1930s, Pauling decided to strike out into new areas of interest. But as Caltech was developing a new strength in biology, and Pauling interacted with such great biologists as Thomas Hunt Morgan, Theodosius Dobzhanski, Calvin Bridges, and Alfred Sturtevant, he started to become interested in studying biological molecules. The best X-ray pictures of proteins in the 1930s had been made by the British crystallographer William Astbury, but when Pauling tried, in 1937, to account for Astbury's observations quantum mechanically, he could not.

It took eleven years for Pauling to explain the problem: his mathematical analysis was correct, but Astbury's pictures were taken in such a way that the protein molecules were tilted from their expected positions. Pauling had formulated a model for the structure of hemoglobin in which atoms were arranged in a helical pattern, and applied this idea to proteins in general.

In 1951, based on the structures of amino acids and peptides and the planarity of the peptide bond, Pauling and colleagues correctly proposed the alpha helix and beta sheet as the primary structural motifs in protein secondary structure.

Pauling then suggested a helical structure for deoxyribonucleic acid (DNA) but in this structure he uncharacteristically made several basic mistakes, including making the phosphate group neutral, a fact which would no longer represent DNA as an acid. When it was learned at the Cavendish Laboratory that Pauling was working on molecular models of the structure of DNA, Watson and Crick were allowed to make a molecular model of DNA using unpublished data from Maurice Wilkins and Rosalind Franklin at King's College. One of the impediments facing Pauling in this work was that he did not have access to the high quality X-ray diffraction photographs of DNA taken by Rosalind Franklin, which Watson and Crick had seen.

Pauling also studied enzyme reactions and was among the first ones to point out that enzymes bring about reactions by stabilizing the transition state of the reaction, a view which is central to understanding their mechanism of action.

Molecular genetics

In November 1949 Linus Pauling, Harvey Itano, S.

Activism

Pauling had been practically apolitical until World War II, but the war changed his life profoundly, and he became a peace activist.

In 1957, Pauling began a petition drive in cooperation with biologist Barry Commoner, who had studied radioactive strontium-90 in the baby teeth of children across North America and concluded that above-ground nuclear testing posed public health risks in the form of radioactive fallout. In 1958, Pauling and his wife presented the United Nations with a petition signed by more than 11,000 scientists calling for an end to nuclear-weapon testing. On the day that the treaty went into force, the Nobel Prize Committee awarded Pauling the Peace Prize, describing him as "Linus Carl Pauling, who ever since 1946 has campaigned ceaselessly, not only against nuclear weapons tests, not only against the spread of these armaments, not only against their very use, but against all warfare as a means of solving international conflicts."

Many of Pauling's critics, including scientists who appreciated the contributions that he had made in chemistry, disagreed with his political positions and saw him as a naïve spokesman for Soviet communism. Pauling was awarded the International Lenin Peace Prize by the USSR in 1970.

Work in the development of the electric car

In the late 1950s, Pauling became concerned with the problem of air pollution - particularly with the growing smog problem in Los Angeles. Pauling worked with Arie Haagen-Smit and others at Caltech to show that smog was a product of automobile pollution instead of factory pollution. Shortly after this discovery, Pauling began work to develop a practical and affordable electric car. After researching the electrophysics underlying the initial Kilowatt propulsion system, Pauling determined that traditional lead-acid batteries would not provide the power necessary to give electric cars the performance necessary to rival traditional gasoline powered cars. Pauling insisted on making the car more practical before releasing it to the public, and recommended that the project be discontinued until the appropriate battery was available commercially.

Work in alternative medicine

In 1941, at age 40, Pauling was diagnosed with a serious form of Bright’s disease, a fatal renal disease. With the help of Dr. Thomas Addis at Stanford, Pauling was able to control the disease with Addis' then unusual, low protein, salt-free diet.

In 1951, Pauling gave a lecture entitled, "Molecular Medicine". In the late 1950s, Pauling worked on the role of enzymes in brain function, believing that mental illness may be partly caused by enzyme dysfunction. Pauling published a brief paper, "Orthomolecular Psychiatry", in the journal Science in 1968 (PMID 5641253) that gave name and principle to the popular but controversial megavitamin therapy movement of the 1970s. Pauling coined the term "orthomolecular" to refer to the practice of varying the concentration of substances normally present in the body to prevent and treat disease.

Pauling's work on vitamin C in his later years generated controversy and was regarded by some adversaries in the field of medicine as outright quackery. Cameron and Pauling wrote many technical papers and a popular book, "Cancer and Vitamin C", that discussed their observations. After three disputed trials at the Mayo Clinic, Pauling, known for his blunt precision and candor, pointedly denounced Moertel's conclusions and handling of the final study as "fraud and deliberate misrepresentation" , Pauling published critiques of the second Mayo-Moertel cancer trial's flaws over several years as he was able to slowly unearth some of the trial's undisclosed details. However, the wave of adverse publicity generated by Moertel and the media effectively undercut Pauling's credibility and his vitamin C work for a generation. Always precariously perched since his molecular biologically inspired crusade to stop atmospheric nuclear testing in the 1950s, the 1985 Mayo-Moertel confrontation left Pauling isolated from his institutional funding sources, academic support and a bemused public.

With two colleagues, Pauling founded the Institute of Orthomolecular Medicine in Menlo Park, California, in 1973, which was soon renamed the Linus Pauling Institute of Science and Medicine. Pauling directed research on vitamin C, but also continued his theoretical work in chemistry and physics until his death from prostate cancer in 1994. In 1996, the Linus Pauling Institute moved from Palo Alto, California, to Corvallis, Oregon, to become part of Oregon State University, where it continues to conduct research on micronutrients, phytochemicals (chemicals from plants), and other constituents of the diet in preventing and treating disease.

Pauling's legacy

Pauling's contribution to science is held by many in the utmost regard. Desiraju, the author of the Millennium Essay in Nature, claimed that Pauling was one of the greatest thinkers and visionaries of the millennium, along with Galileo, Newton, and Einstein. Pauling is also notable for the diversity of his interests: quantum mechanics, inorganic chemistry, organic chemistry, protein structure, molecular biology, and medicine. Although his valence bond approach fell short of accounting quantitatively for some of the characteristics of molecules, such as the paramagnetic nature of oxygen and the color of organometallic complexes, and would later be superseded by the Molecular Orbital Theory of Robert Mulliken, the strength of Pauling's theory has lain in its simplicity, and it has endured. Pauling's work on crystal structure contributed significantly to the prediction and elucidation of the structures of complex minerals and compounds.

In his time, Pauling was frequently honored with the sobriquet "Father of molecular biology", a contribution acknowledged by Francis Crick.

Though the scientific community at large did not agree with Pauling's conclusions in his vitamin-related medical research and writing, his entry into the fray gave a larger voice in the public mind to nutrient such as vitamins and minerals for disease prevention. Pauling's stand also led these subjects to be more much actively investigated by other researchers, including those at the Linus Pauling Institute which lists a dozen principal investigators and faculty who explore the role of micronutrients, plus phytochemicals, in health and disease.

Death

Pauling died of prostate cancer on August 19, 1994 and is buried at Oswego Pioneer Cemetery, Lake Oswego, Oregon, USA.

Honours

Trivia

Works by Linus Pauling