Thomas G. Richmond

Inorganic Chemistry

Associate Professor (b. 1957);
Sc. B., 1979, Brown University;
Ph.D., 1984, Northwestern University;
Myron A. Bantrell Research Fellow, 1983-85,
       California Institute of Technology.

richmond@chemistry.utah.edu

Phone: 801-581-7487



ACS Nobel Laureate Signature Award for Graduate Education, 1998
Presidential Teaching Scholar Award, 1997
ASUU Student’s Choice Award for Teaching, 1993, 1995
Alfred P. Sloan Research Fellowship, 1991-1995
NSF Presidential Young Investigator, 1989-1994
Camille and Henry Dreyfus Distinguished New Faculty Fellow, 1985-86


Research

       Our research in inorganic chemistry continues to focus on the organometallic chemistry of fluorocarbons. We seek to develop transition metal systems which are capable of reacting with fluorocarbons - perhaps the most inert class of compounds created by chemists. In particular we seek new way of selectively activating and functionalizing fluorocarbons using metals as catalysts to control these transformations. We also seek to understand the mechanisms involved in these transformations.

       Our initial foray into this field involved the use of suitably designed chelating ligands to activate and functionalize C-F bonds in aromatic systems as illustrated below for a reaction sequence involving insertion of tungsten into a C-F bond followed by alkyne migratory insertion into the newly formed tungsten-aryl bond.

       The organometallic reaction chemistry of these metal-fluoride complexes has proved to be quite diverse and we have discovered examples of halocarbon coordination compounds, h2-bound aldehyde and ketone complexes, 4-electron donor nitriles and alkynes, and examples of CO and CO2 activation within the context of this ligand framework. Importantly this chemistry also provided the intellectual groundwork for the discovery of intermolecular systems capable of C-F bond activation reactions in totally saturated perfluorocarbons.

       Organometallic reducing agents have proved useful in the selective activation of C-F bonds in saturated perfluorocarbons. For example, the 19-electron complex cobaltocene reacts under mild conditions with perfluorodecalin to liberate fluoride ion and, in the presence of lithium trifluoromethane sulfonate, afford high yields of perfluoronapthalene.

       The first example of a catalytic reaction of this type was discovered in our labs utilizing highly active "zircononcene" produced by reduction of (C5H5)2ZrCl2 with Mg/HgCl2. This system is also capable of reacting with perfluorocyclohexane to ultimately afford 1,2,4,5-tetrafluorobenzene where hydrogenolysis of two aromatic C-F bonds also occurs. Thus we have demonstrated that it is possible to do productive synthetic chemistry with perfluorocarbons despite the great strength of the C-F bond that is responsible for the unique physical and chemical properties of these compounds. The mechanism and scope of these multistep reactions is a topic of current investigation. We are also planning to exploit this class of reactions in the synthesis of new materials.


Selected Publications

M.H.A. Benbenutti, P.B. Hitchcock, J.L. Kiplinger, J.F. Nixon, T.G. Richmond, " Carbon monoxide-phosphaalkyne coupling and C-H activation of an N-Me group in the 4-eh2-phosphaalkyne complex [WF{CH2N(CH2Ph)CH2Ch2NMe2}(CO){4-PCBut(CO)CButP}]," Chem. Commun. 1539-1540 (1997).

J. L. Kiplinger, A. M. Arif, T. G. Richmond, "Influence of p-Conflict on Structure and Reactivity. A Comparative Study of h2-Nitriles and h2-Alkynes as Four Electron Donor Ligands in Tungsten(II) Fluoride Carbonyl Systems," Organometallics 16, 246 (1997).

T. G. Richmond and A. Parr, "A U - Tube Experiment to Discover the Curve in Boyle’s Law," J. Chem. Educ. 74, 414(1997).

J. L. Kiplinger, T.G. Richmond, "Group IV Metallocene Mediated Synthesis of Fluoroaromatics via Selective Defluorination of Saturated Perfluorocarbons," J. Am. Chem. Soc. 118, 1805-1806 (1996).

J. L. Kiplinger, M. A. King, A. Fechtenkötter, A. M. Arif and T. G. Richmond, "An Investigation of Carbon-Fluorine Bond Functionalization. Versatile Reactivity of Tungsten(II) Fluoride Carbonyl Metallacycles with Alkynes," Organometallics 15, 1545(1996).

G. Owens, T. G. Richmond, "Demonstrating Catalysis with a Bang! Initiation of a Hydrogen / Oxygen Explosion With a Pd/C Catalyst," The Chemical Educator 1(4): S 1430-4171 (96) 04045 -9; Avail. URL: http://journals.springer-ny.com/chedr (1996).

J. L. Kiplinger, A. M. Arif, T. G. Richmond, "Synthesis and Reactivity of Tungsten(II) Carbonyl h2 - Nitrile Complexes: Crystal Structure Of Tetrafluoroterephthalonitrile as a Four-Electron Donor Ligand," Chem. Commun. 1691 (1996).

J. L. Kiplinger and T. G. Richmond, "Selective Room Temperature Hydrogenolysis of Aromatic Fluorocarbons Mediated by a Low-Valent Zirconium Complex," Chem. Commun. 1115 (1996).

J. L. Kiplinger, T. G. Richmond, A. M. Arif, C. Dücker-Benfer, R. van Eldik, "Synthesis and Characterization of Highly Fluorinated Tungsten(II) Metallacyclopropene Complexes. Kinetics and Mechanism of an Unprecedented h2-Vinyl Isomerization," Organometallics 15, 1545(1996).

S.D. Looman, S. Giese, A.M. Arif and T.G. Richmond, "p-Basicity of the (Diamine)tricarbonyl-tungsten(0) Fragment Stabilizes h2-Aldehyde Complexes at Tungsten(0), " Polyhedron 15, 2809 (1996).

J.L. Kiplinger and T.G. Richmond, "Selective Room Temperature Hydrogenolysis of Aromatic Fluorocarbons Mediated by a Low-Valent Zicrconium Complex," Chem. Commun. 1115 (1996).

 


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