And after years of teaching budding young chemists at Caltech, he produced his influential textbook General Chemistry , which changed the way chemistry was taught on a global scale. In addition to his contributions to our understanding of molecular disease, Pauling also elucidated the roles of antigens and antibodies in the immune system. At right, his wife, Ava Helen Pauling. In the s and afterward Pauling campaigned tirelessly—and in the face of significant professional and governmental opposition—to put an end to nuclear-bomb tests in the atmosphere and to the arms race.
In , the year that the Nuclear Test Ban Treaty went into effect, Pauling was given the Nobel Peace Prize although given in , the award was for the year Pauling was the second person, after Marie Curie , to win two Nobel Prizes. Pauling stayed at Caltech from to For postgraduate study, Pauling went to the California Institute of Technology Caltech , which provided a stipend for research and teaching.
In he received a Ph. Awarded a Guggenheim Fellowship, in he studied in Europe with physicists who were exploring the implications of quantum mechanics for atomic structure. In this revolutionary new field, Pauling found a physical and mathematical framework for his own future theories regarding molecular structure and its correlation with chemical properties and function.
After Linus Pauling joined the Caltech faculty in the autumn of , he continued his intensive research on the formation of chemical bonds between atoms in molecules and crystals. To chart bond angles and distances characteristic of particular atoms in relation to other atoms, he used x-ray diffraction learned earlier as a graduate student — supplemented after by electron diffraction, an even newer technique that he brought to the U.
Quantum mechanics enabled Pauling to explain the bonding phenomenon theoretically in a far more satisfactory way than before. He began to formulate generalizations regarding the atomic arrangements in crystals with ionic bonding, in which negatively charged electrons, orbiting around the positively charged nucleus, are transferred from one atom to another.
Pauling discovered that in many cases the type of bonding — whether ionic or covalent formed by a sharing of electrons between bonded atoms — could be determined from a substance's magnetic properties. He also established an electronegativity scale of the elements for use in bonds of an intermediate character having both ionic and covalent bonding ; the smaller the difference in electronegativity between two atoms, the more the bond between them approaches a purely covalent bond.
To explain covalent bonding, Pauling introduced two major new concepts, based on quantum mechanics: bond-orbital hybridization and bond resonance. Hybridization reorganizes an atom's electron cloud so that some electrons assume positions favorable for bonding.
Since the carbon atom can form four bonds, tetrahedrally arranged — a central structural feature of organic chemistry — Pauling's explanation of it and of many related features of covalent bonding attracted attention from chemists around the world. Resonance is a rapid jumping of electrons back and forth between two or more possible positions in a bond network.
Resonance makes a major contribution to the structural geometry and stability of many substances, such as benzene or graphite, for which a static, non-resonating bond system would be inadequate. Pauling later extended his bond resonance concept to a theory of bonding in metals and intermetallic compounds. Pauling's innovative concepts, published beginning in the late s, together with numerous examples of their application to particular chemical compounds or compound groups gave chemists fundamental principles to apply to the growing body of chemical knowledge.
They could also accurately predict new compounds and chemical reactions on a theoretical basis that was far more satisfactory than the straight empiricism of pre-Pauling chemistry. In Pauling brought together his work on these subjects in his definitive book The Nature of the Chemical Bond and the Structure of Molecules and Crystals, which became a classic and was translated into many languages.
Its third edition appeared in and has remained in print to this day. Pauling's interest in molecular structure continued throughout his long career, and the theoretical calculations involved meant utter happiness to him.
He used what he called the "stochastic method," which drew upon his own encyclopedic knowledge and formidable memory and allowed him to postulate a likely molecular structure, based on reasoning and theoretical calculation. Detailed laboratory verifications would often be carried out by associates — as with most of his research projects.
Many of his discoveries and inventions were then expanded upon and utilized profitably in the industry by others. And though in later years he was primarily involved in biomedical research, his curiosity often impelled him to identify the intricate structures of many clay minerals, transition metals, intermetallic compounds, and other substances.
In he was awarded one of his last patents for a novel technique of fabricating superconductive materials. In the early s, Pauling took over the teaching of freshman chemistry at Caltech. His modern theoretical approach to chemistry, charismatic lecturing style, and energetic showmanship the laboratory demonstrations occasionally become pyrotechnical displays made him a very popular professor.
He also told students about his current research, giving them insight into the professional chemist's work. In he put his new approach to chemical education into General Chemistry, a textbook that greatly influenced the teaching of chemistry worldwide by redirecting it from its traditional, purely empirical basis into the new "chemical bond approach.
Pauling's involvement with human physiology and health, which dominated the last three decades of his research career, had long precedents. During the mids a significant part of his research, generously funded by the Rockefeller Foundation, moved into biochemistry — a field he had previously avoided — as he became increasingly interested in the highly complex molecules within living organisms. Applying techniques used in earlier diffraction studies to biological compounds, he now sought to understand the structure of proteins.
In he investigated the magnetic properties of hemoglobin, the oxygen-carrying molecule in red blood cells. He then studied the roles of antigens and antibodies in the immune response, one aspect of the important phenomenon of specificity in biochemical interactions.
In he made the novel proposal that this specificity is achieved through molecular complementariness, which he regarded as the secret of life. The concept — involving a "hand-in-glove" fit of one molecule against or into another molecule that has a shape complementary to the first — was tested in his laboratory over the next 10 years by means of numerous serological experiments, yielding results published in no less than 34 scientific papers.
In Pauling postulated that the gene might consist of two mutually complementary strands — a concept anticipating Watson and Crick's discovery of DNA structure seven years later. Pauling originated the concept of molecular disease. In , while hearing a physician describe sickle cell anemia, he instantly surmised that it might be caused by a defect in the red blood cell's hemoglobin.
After three years of painstaking research, he and his associate Dr. Harvey Itano identified this prevalent disease as molecular in origin — caused by a genetically transmitted abnormality in the hemoglobin molecule. In susceptible patients, hemoglobin molecules in venous blood, lacking oxygen, become self-complementary; distorted, they stick together and form long rods that interfere with blood circulation.
Pauling's description of this first molecular disease as he called it initiated a search for many more such disorders. The new idea quickly became immensely important in medicine and is now the main focus of human genome research. Thus the medical specialties of hematology, serology, immunology, applied genetics, and pathology owe much to Pauling's contributions, which were made long before his intense interest in the promise of nutritional therapy became widely known.
Pauling offered the U. He devised some impressive explosives one called "Linusite"! He invented a meter that monitored oxygen levels in submarines and airplanes; the device later provided invaluable in ensuring safe levels of that life-sustaining gas for premature infants in incubators and for surgery patients under anesthesia. With an associate, Dr. Pauling originated a synthetic form of blood plasma for use in emergency transfusions in battlefield clinics.
He also took part in a wartime presidential commission formed to recommend future directions of government-funded scientific and medical research programs. Two major outcomes were the postwar expansion of the National Institutes of Health NIH , allowing for extramural research funding, and the creation of the National Science Foundation.
Acknowledging Pauling's patriotic wartime activities, President Harry Truman in presented the Presidential Medal for Merit to him "for outstanding services to the United States from October to June With the war ended, Pauling again focused on his protein-structure studies at Caltech.
But he had new distractions, brought on by the dawning Atomic Age. At age 14, a visit with a friend who owned a toy chemistry set started Pauling on his life's work. Entranced by the flames, smokes, odors, and by the sight of mysterious changes in solutions and powders, Pauling ran home and began assembling a rough "laboratory" in a corner of his basement.
Here he spent his teenage years seeking order and solace in science. During high school a sympathetic chemistry teacher recognized Pauling's talent and provided special tutoring. At age 16 Pauling dropped out to enroll at Oregon Agricultural College now Oregon State University , intending to pursue a degree in chemical engineering. Pauling quickly demonstrated that he knew more about chemistry than many of his professors.
While still an undergraduate he was asked to teach chemistry courses in the understaffed department, an experience that gave him self-confidence--he became a great lecturer--and access to current chemical journals. Teaching these courses also gave Pauling the opportunity to meet--and later marry--Ava Helen Miller, who was enrolled in his class as part of her home economics coursework. By the time he graduated as a chemical engineer in he had set his sights on answering one of the most important questions of chemistry: how did atoms bond together to form molecules?
In order to find out, he turned from chemical engineering to chemical theory. He enrolled in the first graduate program that offered adequate support, choosing a fledgling Pasadena research school, the California Institute of Technology, or Caltech.
Pauling became one of the first chemistry students in an outstanding doctoral program designed and overseen by the famed chemist Arthur Amos Noyes. Noyes pointed Pauling in the direction of a new experimental technique called x-ray crystallography, which enabled scientists to learn about the sizes and configurations of atoms within molecules and crystals.
Also awarded: The Nobel Peace Prize His family came from a line of Prussian farmers, and his father worked as a pharmaceuticals salesman, among other things. In the s, Linus Pauling's involvement in the anti-nuclear movement led to his being labeled a suspected communist, which resulted in his passport being revoked at times.
Linus and Ava Helen Pauling had four children together. During the s Linus Pauling was among the pioneers who used quantum mechanics to understand and describe chemical bonding - that is, the way atoms join together to form molecules.
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