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Leon O. Morgan

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Leon Owen Morgan (October 25, 1919 – July 29, 2002) was an American academic and Professor of Chemistry at the University of Texas at Austin.[1] He co-discovered the chemical element americium along with Albert Ghiorso, Glenn T. Seaborg and Ralph A. James.[2][3][4]

He studied at the University of Oklahoma, receiving a bachelor's degree in 1941, and at the University of Texas at Austin, receiving a master's degree in 1942. During World War II, he worked under Seaborg on plutonium chemistry in the Manhattan Project in Chicago and in 1944 on the discovery of transuranic elements by irradiating plutonium at the cyclotron in Berkeley.[5][6]

Academic training

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Morgan was born in Oklahoma City in 1919. He graduated summa cum laude from Oklahoma City University in 1941. He then entered the University of Texas at Austin, earning his master's degree in chemistry in 1942.[7]

Early career

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During World War II, Morgan worked on the Manhattan Project, aiming to develop the atomic bomb. He was assigned to the University of Chicago, where he joined the Nuclear Chemistry Metallurgy Research Group under Nobel Laureate Glenn T. Seaborg. There, he worked on the chemistry of plutonium processing, which led to his involvement in the isolation of curium and the discovery of americium in 1944-45. After the war, Morgan completed his PhD under Seaborg at the University of California, Berkeley, in 1947.[8][1]

Scientific career

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Search for new elements

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Morgan was part of the Laboratory of Metallurgy (LabMet) at the University of Chicago[8][9], directed by Glenn T. Seaborg. With sufficient plutonium available, Seaborg instructed chemists Ralph A. James and Leon O. Morgan to irradiate plutonium in the Berkeley cyclotron, sending samples to Chicago for analysis by Albert Ghiorso.[10] They confirmed the presence of americium by identifying characteristic alpha particles emitted by the activated samples.[3][11][12]

Discovery of americium

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Americium (atomic number 95) was discovered in 1944-45 by Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, and Albert Ghiorso by irradiating plutonium with neutrons in the 60-inch cyclotron at the University of California, Berkeley.[11][13][14][15] The element is named after America, especially the United States of America.[13]

Academic career

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In 1947, after completing his PhD, Morgan joined the Department of Chemistry at the University of Texas at Austin, where he retired as professor emeritus in 1993.[16] He initiated a nuclear chemistry and radiochemistry program focusing on elements such as tungsten, rhenium, and osmium, and the study of electrochemical processes.[17] His grad students included Harold M. Goff and Conrad C. Hinckley.[18]

He directed the first-year chemistry program, taught various classes, and supervised many graduate students and postdoctoral fellows. In the mid-1950s, Morgan investigated nuclear magnetic resonance spectroscopy, contributing to the development of the Solomon-Bloembergen-Morgan (SBM) theory, which laid the groundwork for magnetic resonance imaging (MRI)[16], a critical diagnostic tool in medicine.

Morgan served in various capacities at the university, including graduate advisor in chemistry, chairman of the Graduate School, member of the University Intercollegiate Athletics Council, and chairman of the Advisory Committee after his retirement.

His later research focused on the dissolution of transition metal coordination complexes, emphasizing biological interest structures like the iron-porphyrin structures in hemoglobin and cytochrome c.[16]

Other positions

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Beyond his academic career, Morgan consulted with colleagues at the Los Alamos Scientific Laboratory in New Mexico and was an associate editor of the ACS Journal of Physical Chemistry (around 1964).

Death

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Leon Owen Morgan passed away on July 29, 2002, in Austin, Texas, at the age of 82.[7]

Publications[19]

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  • 1978: Goff HM, Morgan LO. Carbon-13 and proton nuclear magnetic resonance spectroscopy of water-soluble porphyrins and metalloporphyrins. Bioinorganic Chemistry. 9: 61-79. PMID 687673 DOI: 10.1016/S0006-3061(00)82006-2
  • 1976: Morgan LO, Eakin RT, Vergamimi PJ, Matwiyoff NA. Carbon-13 nuclear magnetic resonance of heme carbonyls. Cytochrome c and carboxymethyl derivatives of cytochrome c. Biochemistry. 15: 2203-7. PMID 6042
  • 1976: Goff H, Morgan LO. Magnetic properties of iron(III) porphyrin dimers in aqueous solution. Inorganic Chemistry. 15: 3180-3181.
  • 1975: Fuentes R, Morgan LO, Matwiyoff NA. Fourier transform carbon-13 nuclear magnetic resonance of aqueous nickel(II)-acetic acid solutions. I. Equilibrium quotients from relative abundances of solution species. Inorganic Chemistry. 14: 1837-1840.
  • 1970: Matwiyoff NA, Strouse CE, Morgan LO. Carbon-13 and oxygen-17 nuclear magnetic resonance studies of the structure of the nickel(II)-ethylenediaminetetraacetate complexes in aqueous solution. Journal of the American Chemical Society. 92: 5222-5224. DOI: 10.1021/Ja00720A040
  • 1970: Hempel JC, Morgan LO, Lewis WB. Electron paramagnetic resonance of trans-disubstituted bis(ethylenediamine)chromium(III) complexes in frozen solutions. Inorganic Chemistry. 9: 2064-2072.
  • 1970: Zeltmann AH, Morgan LO. Ligand substitution processes in aqueous cobalt(II)-thiocyanate solutions. Nuclear magnetic resonances of oxygen-17 and nitrogen-14. Inorganic Chemistry. 9: 2522-2528.
  • 1969: Garrett BB, Morgan LO. Erratum: Electron Spin Relaxation in Solvated Manganese (II) Ion Solutions. The Journal of Chemical Physics. 50: 3135-3136. DOI: 10.1063/1.1671533
  • 1969: Zeltmann AH, Matwiyoff NA, Morgan LO. Nuclear magnetic resonance of oxygen-17 and chlorine-35 in aqueous hydrochloric acid solutions of cobalt (II). II. Relaxation and chemical exchange. Journal of Physical Chemistry. 73: 2689-2696.
  • 1968: Zeltmann AH, Matwiyoff NA, Morgan LO. Nuclear magnetic resonance of oxygen-17 and chlorine-35 in aqueous hydrochloric acid solutions of cobalt(II). I. Line shifts and relative abundances of solution species. Journal of Physical Chemistry. 72: 121-127.
  • 1967: Alei M, Lewis WB, Denison AB, Morgan LO. Magnetic resonance studies on copper (II) complex ions in solution. III. NMR and EPR in concentrated ethylenediamine solutions. The Journal of Chemical Physics. 47: 1062-1070.
  • 1966: Zeltmann AH, Morgan LO. Nuclear Magnetic Resonance of Oxygen-17 and Chlorine-35 in Aqueous Hydrochloric Acid Solutions of Iron(III). The Journal of Physical Chemistry. 70: 2807-2813. DOI: 10.1021/j100881a016
  • 1966: Garreti BB, Morgan LO. Electron spin relaxation in solvated manganese (II) ion solutions. The Journal of Chemical Physics. 44: 890-897.
  • 1966: Hinckley CC, Morgan LO. Electron spin resonance linewidths of manganese (II) ions in concentrated aqueous solutions. The Journal of Chemical Physics. 44: 898-905.
  • 1963: Morgan LO. On hydration of gadolinium (III) ions in aqueous solution. The Journal of Chemical Physics. 38: 2788-2789.
  • 1961: Bloembergen N, Morgan LO. Proton relaxation times in paramagnetic solutions. Effects of electron spin relaxation. The Journal of Chemical Physics. 34: 842-850.
  • 1959: Cox PF, Morgan LO. Proton spin relaxation in aqueous solutions of paramagnetic ions. IV. Temperature dependence in solutions of copper(II)-ethylenediamine complexes. Journal of the American Chemical Society. 81: 6409-6412.
  • 1959: Morgan LO, Nolle AW. Proton spin relaxation in aqueous solutions of paramagnetic ions. II. Cr+++, Mn++, Ni++, Cu++, and Gd+++. The Journal of Chemical Physics. 31: 365-368.
  • 1959: Morgan LO, Murphy J, Cox PF. Proton spin relaxation in aqueous solutions of paramagnetic ions. III. Copper(II)-diamine complexes. Journal of the American Chemical Society. 81: 5043-5047.
  • 1957: Nolle AW, Morgan LO. Frequency dependence of proton spin relaxation in aqueous solutions of paramagnetic ions. The Journal of Chemical Physics. 26: 642-648.
  • 1956: Morgan LO, Murphy J, Nolle AW. Proton spin relaxation in water-glycerin solutions of chromium (III) ions. The Journal of Chemical Physics. 24: 906-907.
  • 1956: Morgan LO, Nolle AW, Hull RL, Murphy J. Proton relaxation in solutions of chromium (III) complexes. The Journal of Chemical Physics. 25: 206-208.
  • 1950: Ghiorso A, James RA, Morgan LO, Seaborg GT. Preparation of transplutonium isotopes by neutron irradiation. Physical Review. 78: 472. DOI: 10.1103/Physrev.78.472

References

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  1. ^ a b "Chemistry Tree - Leon Owen Morgan". academictree.org. Retrieved 2024-08-12.
  2. ^ The Elements. PediaPress.
  3. ^ a b Jaffe, Bernard (2012-07-12). Crucibles: The Story of Chemistry from Ancient Alchemy to Nuclear Fission. Courier Corporation. ISBN 978-0-486-14184-8.
  4. ^ United States Government Publications Monthly Catalog. U.S. Government Printing Office. 1949.
  5. ^ Communications, Emmis (February 1962). The Alcalde. Emmis Communications.
  6. ^ Hoffman, Darleane C.; Ghiorso, Albert; Seaborg, Glenn T. (2000-01-21). Transuranium People, The: The Inside Story. World Scientific. ISBN 978-1-78326-244-1.
  7. ^ a b "Leon O. (Tom) Morgan - Nuclear Museum". ahf.nuclearmuseum.org/. Retrieved 2024-07-23.
  8. ^ a b "It's Elemental - The Element Americium". education.jlab.org. Retrieved 2024-10-28.
  9. ^ Hofmann, Sigurd (2018-10-08). On Beyond Uranium: Journey to the End of the Periodic Table. CRC Press. ISBN 978-1-4822-6517-0.
  10. ^ Choppin, Gregory; Liljenzin, Jan-Olov; Rydberg, Jan; Ekberg, Christian (2013-09-05). Radiochemistry and Nuclear Chemistry. Academic Press. ISBN 978-0-12-397868-4.
  11. ^ a b Seaborg, Glenn Theodore (1994). Modern Alchemy: Selected Papers of Glenn T. Seaborg. World Scientific. ISBN 978-981-02-1440-1.
  12. ^ Seaborg, Glenn Theodore (1994). Modern Alchemy: Selected Papers of Glenn T. Seaborg. World Scientific. ISBN 978-981-02-1440-1.
  13. ^ a b "95. Americium - Elementymology & Elements Multidict". elements.vanderkrogt.net. Retrieved 2024-09-12.
  14. ^ https://orau.org/health-physics-museum/files/library/americiumdiscovery.pdf The New Element Americium (Atomic Number 95). Seaborg, G.T.; James, R.A.; Morgan, Leon O., January 1948
  15. ^ Emsley, John (2011-08-25). Nature's Building Blocks: An A-Z Guide to the Elements. OUP Oxford. ISBN 978-0-19-960563-7.
  16. ^ a b c "Leon O Morgan - Chem & Biochem - UT Austin". canov.jergym.cz. Retrieved 2024-07-23.
  17. ^ "Leon O Morgan - Chem & Biochem - UT Austin". canov.jergym.cz. Retrieved 2024-10-31.
  18. ^ "Chemistry Tree - Leon Owen Morgan". academictree.org. Retrieved 2024-11-08.
  19. ^ "Leon Owen Morgan - Publications". academictree.org. Retrieved 2024-09-15.
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