Robert D. Shannon

Last updated
Robert D. Shannon
Born (1935-08-28) 28 August 1935 (age 88)
Highland Park, Michigan, U.S.
Alma materB.S. 1957, M.S. 1959 University of Illinois
Ph.D 1964 University of California at Berkeley
Known forIonic Radii tabulations
Inorganic chemistry
Dielectric Properties
Noble-Metal Oxides
Scientific career
Fields Chemistry
Institutions DuPont de Nemours, Inc.

Robert Day Shannon (born 1935) is a retired research chemist formerly at DuPont de Nemours, Inc. [1]

Contents

Career

Shannon received his B.S. and M.S. degrees in Ceramic Engineering from the University of Illinois in 1957 and 1959. He then went on to receive his Ph.D. in Ceramic Engineering from the University of California at Berkeley in 1960. He then joined the DuPont Company as a research chemist from 1964 to 1971 where he concentrated on high-pressure synthesis and precious metal oxide chemistry. He then spent 1971 conducting post-doctorate studies at McMaster University in Hamilton, Ontario, working with Chris Calvo on the crystal structures of a number of vanadates [2] and with David Brown on bond strength-bond length relationships useful in determining H locations in hydroxides and hydrates. [3] Next, he took a sabbatical leave from DuPont and spent 1972 at the CNRS and teaching at the University of Grenoble, France as a visiting professor, where he presented a course on solid state chemistry and conducted research on high-pressure chemistry of vanadates. [4] He returned to DuPont in 1973 to do research on new ionic conductors and precious metal oxide chemistry.

In 1982, he was granted another sabbatical leave from DuPont and worked on catalysis with zeolites at the Institute de Catalyse in Lyon, France. Upon completion of the sabbatical, he returned to DuPont and worked for another ten years before retiring in 1992.

After retirement, he received a grant from the Alexander von Humboldt Foundation to continue his research on ion polarizabilities in collaboration with Reinhard Fischer in 1994 at the Universities of Mainz and Bremen in Germany and with Olaf Medenbach at the Ruhr-Universität in Bochum, Germany. There, he prepared three papers on refractive indices and electronic polarizabilities in oxides, and other compounds. [5] He has since moved to Colorado where he has been associated with the University of Colorado Boulder · Cooperative Institute for Research in Environmental Sciences (CIRES). [6]

Shannon was a member of the American Chemical Society and the American Crystallographic Association. He was elected a Fellow of the Mineralogical Society of America. [7] He has served on the Evaluation Panel for Materials Science at the National Bureau of Standards, and on the National Science Foundation Subcommittee for Oversight Review of Solid State Chemistry.

Research

Shannon has about 164 publications that, together, have received over 77 thousand citations. [8] His work on ionic radii of ions has drawn particularly wide attention. In a 2014 Nature paper [9] his 1976 work on the ionic radii of ions [10] was recognized as the 22d most cited paper in all of science. It is also been cited as the highest formally-cited database of all time. [9] He has a number of patents on glass compositions, zeolite catalysts, noble-metal oxide, electrodes, and chemical compounds. [11]

Mineral named in his honor

The mineral bobshannonite, [12] Na2KBa(Mn,Na)8(Nb,Ti)4(Si2O7)4O4(OH)4(O,F)2, was named in his honor in recognition of his major contributions to the field of crystal chemistry in particular and mineralogy in general through his development of accurate and comprehensive ionic radii and his work on dielectric properties of minerals. [13]

Selected highly cited publications

Related Research Articles

<span class="mw-page-title-main">Salt (chemistry)</span> Chemical compound involving ionic bonding

In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions (cations) and negatively charged ions (anions), which results in a compound with no net electric charge. The constituent ions are held together by electrostatic forces termed ionic bonds.

<span class="mw-page-title-main">Perchloric acid</span> Chemical compound

Perchloric acid is a mineral acid with the formula HClO4. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid and hydrochloric acid. It is a powerful oxidizer when hot, but aqueous solutions up to approximately 70% by weight at room temperature are generally safe, only showing strong acid features and no oxidizing properties. Perchloric acid is useful for preparing perchlorate salts, especially ammonium perchlorate, an important rocket fuel component. Perchloric acid is dangerously corrosive and readily forms potentially explosive mixtures.

Ionic radius, rion, is the radius of a monatomic ion in an ionic crystal structure. Although neither atoms nor ions have sharp boundaries, they are treated as if they were hard spheres with radii such that the sum of ionic radii of the cation and anion gives the distance between the ions in a crystal lattice. Ionic radii are typically given in units of either picometers (pm) or angstroms (Å), with 1 Å = 100 pm. Typical values range from 31 pm (0.3 Å) to over 200 pm (2 Å).

<span class="mw-page-title-main">Bismuth(III) oxide</span> Chemical compound

Bismuth(III) oxide is a compound of bismuth, and a common starting point for bismuth chemistry. It is found naturally as the mineral bismite (monoclinic) and sphaerobismoite, but it is usually obtained as a by-product of the smelting of copper and lead ores. Dibismuth trioxide is commonly used to produce the "Dragon's eggs" effect in fireworks, as a replacement of red lead.

<span class="mw-page-title-main">Chromium hexacarbonyl</span> Chemical compound

Chromium hexacarbonyl is a chromium(0) organometallic compound with the formula Cr(CO)6. It is a homoleptic complex, which means that all the ligands are identical. It is a colorless crystalline air-stable solid, with a high vapor pressure.

<span class="mw-page-title-main">Vanadate</span> Coordination complex of vanadium

In chemistry, a vanadate is an anionic coordination complex of vanadium. Often vanadate refers to oxoanions of vanadium, most of which exist in its highest oxidation state of +5. The complexes [V(CN)6]3− and [V2Cl9]3− are referred to as hexacyanovanadate(III) and nonachlorodivanadate(III), respectively.

<span class="mw-page-title-main">Silver azide</span> Chemical compound

Silver azide is the chemical compound with the formula AgN3. It is a silver(I) salt of hydrazoic acid. It forms a colorless crystals. Like most azides, it is a primary explosive.

<span class="mw-page-title-main">Ruthenium(IV) oxide</span> Chemical compound

Ruthenium(IV) oxide is the inorganic compound with the formula RuO2. This black solid is the most common oxide of ruthenium. It is widely used as an electrocatalyst for producing chlorine, chlorine oxides, and O2. Like many dioxides, RuO2 adopts the rutile structure.

Osmium compounds are compounds containing the element osmium (Os). Osmium forms compounds with oxidation states ranging from −2 to +8. The most common oxidation states are +2, +3, +4, and +8. The +8 oxidation state is notable for being the highest attained by any chemical element aside from iridium's +9 and is encountered only in xenon, ruthenium, hassium, iridium, and plutonium. The oxidation states −1 and −2 represented by the two reactive compounds Na
2[Os
4(CO)
13] and Na
2[Os(CO)
4] are used in the synthesis of osmium cluster compounds.

<span class="mw-page-title-main">Niobium pentoxide</span> Chemical compound

Niobium pentoxide is the inorganic compound with the formula Nb2O5. A colorless, insoluble, and fairly unreactive solid, it is the most widespread precursor for other compounds and materials containing niobium. It is predominantly used in alloying, with other specialized applications in capacitors, optical glasses, and the production of lithium niobate.

Acta Crystallographica is a series of peer-reviewed scientific journals, with articles centred on crystallography, published by the International Union of Crystallography (IUCr). Originally established in 1948 as a single journal called Acta Crystallographica, there are now six independent Acta Crystallographica titles:

<span class="mw-page-title-main">Osmium dioxide</span> Chemical compound

Osmium dioxide is an inorganic compound with the formula OsO2. It exists as brown to black crystalline powder, but single crystals are golden and exhibit metallic conductivity. The compound crystallizes in the rutile structural motif, i.e. the connectivity is very similar to that in the mineral rutile.

Barium orthotitanate is the inorganic compound with the chemical formula Ba2TiO4. It is a colourless solid that is of interest because of its relationship to barium titanate, a useful electroceramic.

<span class="mw-page-title-main">Sodium germanate</span> Chemical compound

Sodium germanate is an inorganic compound with the chemical formula Na2GeO3. It exists as a colorless solid. Sodium germanate is primarily used for the synthesis of other germanium compounds.

<span class="mw-page-title-main">Cyanonickelate</span> Class of chemical compounds

The cyanonickelates are a class of chemical compound containing anions consisting of nickel atoms, and cyanide groups. The most important of these are the tetracyanonickelates containing four cyanide groups per nickel. The tetracyanonickelates contain the [Ni(CN)4]2− anion. This can exist in solution or in solid salts. The ion has cyanide groups arranged in a square around the central nickel ion. The symmetry of the ion is D4h. The distance from the nickel atom to the carbon is 1.87 Å, and the carbon-nitrogen distance is 1.16 Å. In their crystals, the tetracyanonickelate(II) anions are often arranged in a columnar structure (e.g. in K2[Ni(CN)4]). Tetracyanonickelate(II) can be oxidised electrochemically in solution to yield tetracyanonickelate(III) [Ni(CN)4]−. [Ni(CN)4]− is unstable and Ni(III) oxidises the cyanide to cyanate OCN−. Tetracyanonickelate(III) can add two more cyanide groups to form hexacyanonickelate(III).

<span class="mw-page-title-main">Nickel oxyacid salts</span>

The Nickel oxyacid salts are a class of chemical compounds of nickel with an oxyacid. The compounds include a number of minerals and industrially important nickel compounds.

A selenate selenite is a chemical compound or salt that contains selenite and selenate anions (SeO32- and SeO42-). These are mixed anion compounds. Some have third anions.

A tellurite tellurate is chemical compound or salt that contains tellurite and tellurate anions [TeO3]2- [TeO4 ]2-. These are mixed anion compounds, meaning the compounds are cations that contain one or more anions. Some have third anions. Environmentally, tellurite [TeO3]2- is the more abundant anion due to tellurate's [TeO4 ]2- low solubility limiting its concentration in biospheric waters. Another way to refer to the anions is tellurium's oxyanions, which happen to be relatively stable.

Alexander Frank Wells, or A. F. Wells, was a British chemist and crystallographer. He is known for his work on structural inorganic chemistry, which includes the description and classification of structural motifs, such as the polyhedral coordination environments, in crystals obtained from X-ray crystallography. His work is summarized in a classic reference book, Structural inorganic chemistry, first appeared in 1945 and has since gone through five editions. In addition, his work on crystal structures in terms of nets have been important and inspirational for the field of metal-organic frameworks and related materials.

Charles Thompson Prewitt was an American mineralogist and solid state chemist known for his work on structural chemistry of minerals and high-pressure chemistry.

References

  1. ↑ Van Noorden, Richard; Maher, Brendan; Nuzzo, Regina (2014). "The top 100 papers". Nature. 514 (7524): 550–553. Bibcode:2014Natur.514..550V. doi: 10.1038/514550a . PMID   25355343. S2CID   4466906.
  2. ↑ Shannon RD, Calvo C (1973) Refinement of Crystal-Structure of Low-Temperature Li3VO4 and Analysis of Mean Bond Lengths in Phosphates, Arsenates, and Vanadates. Journal of Solid state Chemistry 6, 538–549.
  3. ↑ Brown ID, Shannon RD (1973) Empirical Bond Strength – Bond-Length Curves for Oxides. Acta Crystallographica Section A, 29. 266–282.
  4. ↑ Gondrand M, Collomb A, Joubert JC, Shannon RD (1974) Synthesis of new high-pressure columbite phases containing petntavalent vanadium. Journal of Solid State Chemistry 11, 1–9.
  5. ↑ Medenbach O, Shannon RD (1997) Refractive indices and optical dispersion of 103 synthetic and mineral oxides and silicates measured by a small-prism technique. Journal of the Optical Society of America B – Optical Physics 14, 3299–3318.
  6. ↑ "Robert D. Shannon". ResearchGate .
  7. ↑ "Fellows". Mineralogical Society of America.
  8. ↑ "Robert SHANNON | Research Associate | University of Colorado Boulder, CO | CUB | Cooperative Institute for Research in Environmental Sciences (CIRES)".
  9. 1 2 van Noorden R, Maher B, Nuzzo R (2014) The top 100 Papers – the most-cited research of all time. Nature 514, 550–553.
  10. ↑ Shannon RD (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, Section A: Crystal Physics, Diffraction, Theoretical and General Crystallography, A32, 751–67.
  11. ↑ "Robert D. Shannon Inventions, Patents and Patent Applications – Justia Patents Search".
  12. ↑ "Bobshannonite".
  13. ↑ Sokolova E, Cámara F, Abdu YA, Hawthorne FC, Horváth L, Pfenninger-Horváth E (2018) Bobshannonite, Na2KBa(Mn,Na)8(Nb,Ti)4(Si2O7)4O4(OH)4(O,F)2, a new TS-block mineral from Mont Saint-Hilaire, Québec, Canada: Description and crystal structure. Mineralogical Magazine 79, 1791–1811.
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