Pauling studies

Linus Pauling (1901-1994) was born in Portland Ore gon and was educated at Oregon State University and at the California Institute of Technology where he earned a Ph D in chemistry in 1925 In addition to re search in bonding theory Pauling studied the structure of proteins and was awarded the Nobel Prize in chemistry for that work in 1954 Paul ing won a second Nobel Prize (the Peace Prize) in 1962 for his efforts to limit the testing of nuclear weapons He was one of only four scientists to have won two Nobel Prizes The first double winner was a woman Can you name her" ... 

Photo 5 (left) Linus Pauling with Arnold Sommerfeld (on left). Sommerfeld, well-known professor of theoretical physics in the University of Munich, Germany, was an expert on an early form of quantum mechanics, the Bohr-Sommerfeld atomic model. The picture was taken on the occasion of Sommerfeld s visit to Caltech in 1928. Pauling studied quantum mechanics with Sommerfeld in 1926—1927, which is where Pauling got his start in the application of quantum mechanics to chemical bonding (Chapter 1) and to the calculation of molecular properties (Chapter 8). 

After World War II Pauling studied sickle cell anemia, and theorized that it was the result of a genetically based defect in the patient s hemoglobin molecules. In 1949 he and Harvey Itano confirmed this theory they had identified what they called a molecular disease, one that could be defined by a molecular abnormality. In 1954 Pauling received the Nobel Prize in chemistry for his research on the chemical bond and its appfication to the elucidation of the structure of complex substances. ... 

In addition, Paul studied the behavior of jet swell with wet-spinning solution. Specifically, he measured the ratio DjID (where Df is the diameter of filaments attained if diffusional exchange does not alter solids level or density and if D is the diameter of the spinneret) vs These data, given in Fig. 11-20 for... 

Paddison and Paul studied the diffusion of protons in fully hydrated Nafion (> =22.5) with nonequilibrium statistical mechanical transport model. The model calculated a diffusion coefficient for a proton moving along the pore center of 1.92x10" cmVs. Within 4A of the pore center proton transfer via the Grotthuss mechanism, while within 8A of the wall of the pore, the transport of the proton is predominantly vehicular in nature. 

Nonclassical ions, a term first used by John Roberts (an outstanding Caltech chemist and pioneer in the field), were defined by Paul Bartlett of Harvard as containing too few electrons to allow a pair for each bond i.e., they must contain delocalized (T-electrons. This is where the question stood in the early 1960s. The structure of the intermediate 2-norbornyl ion could only be suggested indirectly from rate (kinetic) data and observation of stereochemistry no direct observation or structural study was possible at the time. 

The primary structure of a peptide is its ammo acid sequence We also speak of the secondary structure of a peptide that is the conformational relationship of nearest neighbor ammo acids with respect to each other On the basis of X ray crystallographic studies and careful examination of molecular models Linus Pauling and Robert B Corey of the California Institute of Technology showed that certain peptide conformations were more stable than others Two arrangements the a helix and the (5 sheet, stand out as... 

In 1954 the surface fluorination of polyethylene sheets by using a soHd CO2 cooled heat sink was patented (44). Later patents covered the fluorination of PVC (45) and polyethylene bottles (46). Studies of surface fluorination of polymer films have been reported (47). The fluorination of polyethylene powder was described (48) as a fiery intense reaction, which was finally controlled by dilution with an inert gas at reduced pressures. Direct fluorination of polymers was achieved in 1970 (8,49). More recently, surface fluorinations of poly(vinyl fluoride), polycarbonates, polystyrene, and poly(methyl methacrylate), and the surface fluorination of containers have been described (50,51). Partially fluorinated poly(ethylene terephthalate) and polyamides such as nylon have excellent soil release properties as well as high wettabiUty (52,53). The most advanced direct fluorination technology in the area of single-compound synthesis and synthesis of high performance fluids is currently practiced by 3M Co. of St. Paul, Minnesota, and by Exfluor Research Corp. of Austin, Texas. 

After 1930, when the true nature of polymers was at last generally, recognised, the study of polymers expanded from being the province of organic specialists physical chemists like Paul Flory and physicists like Charles Frank became involved. In this short chapter, I shall be especially concerned to map this broadening range of research on polymers. 

Hydrogen is unusual because it can form both a cation (1I+) and ail anion (11 ). Moreover, its intermediate electronegativity (2.2 on the Pauling scale) means that it can also form covalent bonds with all the nonmetals and metalloids. Because hydrogen forms compounds with so many elements (Table 14.2 also see Section 14.2), we shall meet more of its compounds when we study the other elements. 

There is evidence from electron diffraction studies of pyrazine and pyridine that this value should be increased by 0.01 or 0.02 A because of the electronegativity of nitrogen (V. Schomaker and L. Pauling, paper to be published in Jour. Am. Chem. Soc.). 

Photo 8 Linus Pauling with Charles D. Coryell (left), who collaborated in the study of the magnetic properties of hemoglobin (SP 83, SP 84). Picture taken about 1933. 

Photo 14 Linus Pauling in 1950, showing his still evident enthusiasm for the structures of complex minerals (Chapters 5, 6), in this case possibly beryl. In a typical pose, he holds a specimen of the mineral and stands beside an atomic model. The enthusiasm for minerals continued even though Pauling had by this time largely moved on to studies of biological macromolecules (Part III). 

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