John Selegue

selegue's picture
Education: 
Ph.D. Massachusetts Institute of Technology, 1979
Graduate Training: 
Inorganic and Organometallic Chemistry
Research: 

We are investigating the synthesis, characterization and reactivity of new inorganic and organometallic molecules and materials. New materials are characterized by a variety of physical methods including X-ray diffraction and NMR.

1. Organotransition Metal Chemistry. Organometallic chemistry is one of the most active areas of modern chemical research. Many of our target complexes are models for putative intermediates in industrially important reactions such as the conversion of synthesis gas (CO/H2) or acetylene to useful organic products. We are particularly interested in complexes of small, all-carbon ligands. The tungsten-catalyzed alkyne metathesis of [Ru(CCMe)(CO)2(Cp)] leads to either [(Cp)(CO)2Ru(µ-C)W(OCMe3)3] or [{Ru(CO) 2(Cp)}2(µ-CC)] (1), depending on reaction conditions. The ethynediyl (C2) ligand of 1 reacts with transition metal carbonyls to form heteronuclear bicarbide clusters such as [Fe2Ru2 (µ4-CC)(µ-CO)(CO)8(eta-C5H5)2] (2). The reaction of Na[Fe(CO)2(Cp)] with [C3Cl3][SbF6] produces a cyclo-C3 complex, [{Fe(CO)2(Cp)}3 (µ3-C3)][SbF6] (3).

We are also studying complexes of cumulated carbenes such as vinylidene (C=CH2) and allenylidene (C=C=CH2). For example, the reaction of acetylene with [RuCl(PMe2Ph)2(Cp)] leads to kinetically favored [Ru(eta2-HCCH)(PMe2Ph)2(Cp)]+ (4), which rearranges to its thermodynamically favored vinylidene isomer [Ru(C=CH2)(PMe2Ph)2(Cp)]+ (5) above 60oC.

Interactions of thiophenes with transition metals are important both in the hydrodesulfurization of fossil fuels and in the area of electrically conducting polythiophenes. We are especially interested in benzo[c]thiophene, which readily polymerizes to a conducting polymer with a small electronic band gap. We have prepared both sigma- and pi-bonded organometallic derivatives of benzo[c]thiophene, namely [Cr(eta6-C8H6S)(CO)3] (5) and [{Ru(CO)2(Cp)}2(µ2-C8H4S)] (6).

2. Fullerene Chemistry. The discovery of C60, C70, and larger cagelike molecular allotropes of carbon has revolutionized the study of this element. We are interested in several aspects of these new materials. A HPLC method developed in collaboration with Prof. Meier allows us to separate and purify significant quantities of fullerenes and their derivatives. The larger fullerenes C76, C78 and C84 were purified by HPLC and studied electrochemically. We are developing new fulleride salts with metal-complex cations.

3. Low-Dimensional Materials. In the intercalation process, guest molecules such as cobaltocene enter the space between the layers of inorganic hosts such as FeOCl and TaS2, generally with concomitant charge transfer. Intercalation modifies the physical properties of the host as well as the chemical properties of the guest. We are developing new intercalation compounds with organometallic guests.

Selected Publications: 
  • J. R. Lomprey and J. P. Selegue, "Structural Characterization of Alkyne and Vinylidene Isomers of [Ru(C2H2)(PMe2Ph)2(Cp)][BF4]," J. Am. Chem. Soc., 114, 5518-5523 (1992).
  • G. A. Koutsantonis, J. P. Selegue and J.-G. Wang, "Cluster Building on a Bicarbide Fragment: Synthesis and Structure of [Fe2Ru2 (m4-CC)(m-CO)(CO) 8 (h-C5H5)2]," Organometallics, 11, 2704-2708 (1992).
  • M. S. Meier, T. F. Guarr, J. P. Selegue and V. K. Vance, "Elevated Temperature Gel Permeation Chromatography and Electrochemical Behavior of the C84 Fullerene," J. Chem. Soc., Chem. Commun., 63-65 (1993).
  • J. R. Lomprey and J. P. Selegue, "Syntheses and Structures of Two Trifluoroacetate- Trapped Derivatives of a Ruthenium Butatrienylidene Complex," Organometallics, 12, 616-617 (1993).
  • J. P. Selegue and K. A. Swarat, "Preparation and Structure of [Cr(h6-C8H6S)(CO)3], the First Transition Metal Complex of Benzo[3,4-c]thiophene," J. Am. Chem. Soc., 115, 6448-6449 (1993).
  • M. Chung, K. Wang, P. C. Eklund, J. W. Brill, X.-D. Xiang, R. Mostovov, J.-G. Hou, A. Zettle, J. F. Davis, A. Golden, M. S. Meier and J. P. Selegue, "Thermal Properties of Fullerenes," Synth. Metals, 55-57, 2985-2990 (1993).
  • S. Dev and J. P. Selegue, "Convenient Syntheses of [RuCl(CO)2(Cp)] and [OsCl(CO)2(Cp)]," J. Organometal. Chem., 469, 107-110 (1994).
  • M. S. Meier, M. Poplawska, A. Compton, J. Shaw, J. P. Selegue and T. F. Guarr, "Preparation and Isolation of Three Isomeric C70 Isoxazolines: Strong Deshielding in the Polar Region of C70," J. Am. Chem. Soc., 116, 7044-7048 (1994).
  • B. Addison-Jones, P. W. Percival, J-C. Brodovitch, F. Ji, S. Wlodek, J. P. Selegue, M. S. Meier and J. B. Wakefield, "Muon Investigations of Fullerenyl Radicals," Hyperfine Interactions, 86, 817-824 (1994).
  • J. P. Selegue, J. P. Shaw, T. F. Guarr and M. S. Meier, "Purification and Characterization of the Larger Fullerenes: New Aspects of C76, C78 and C84," in Recent Advances in the Physics and Chemistry of Fullerenes, The Electrochemical Society, 1274-1291 (1994).
  • J. P. Selegue, S. Dev, T. F. Guarr, J. W. Brill and E. Figueroa, "Synthesis and Characterization of Fulleride Salts with Metal Complex Cations," in Recent Advances in the Physics and Chemistry of Fullerenes, The Electrochemical Society, 1245-1254 (1994).
  • R. A. Keogh, J. P. Selegue, B. Shi and B. H. Davis, "Coal Liquefaction. Role of Fullerite C60/C70 During the Conversion of a Coal and a Model Compound," 11th Annual International Pittsburgh Coal Conference Proceedings, S.-H. Chiang, Ed., September 12-16, 1994, Pittsburgh, PA, pp. 493-499.
  • E. Figueroa, Y.-K. Kuo, A. Olinger, M. A. Lloyd, L. D. Bastin, S. Petrotsatos, Q. Chen, B. Dobbs, S. Dev, J. P. Selegue, L. E. DeLong, C. P. Brock and J. W. Brill, "Physical Properties of 6R-TaS2," J. Solid State Chem., 114, 486-490 (1995).
  • M. S. Morton and J. P. Selegue, "A Cyclopropenylidene Approach to Tricarbide Complexes: Synthesis and Structure of [{Fe(CO)2(Cp)}3(m3-C3)][SbF6]," J. Am. Chem. Soc., 117, 7005-7006 (1995).
  • E. Figueroa, J. W. Brill and J. P. Selegue, "New Intercalation Compounds of Transition Metal Dichalcogenides," J. Phys. Chem. Solids, 57, 1123-1127 (1996).
  • C. S. Griffith, G. A. Koutsantonis, C. L. Raston, J. P. Selegue, B. W. Skelton and A. H. White, "A Re-Investigation of the Reaction of [RuCl2(CO)3]2 with C5H5(Me3Si): X-Ray Structure Determination of [Ru(CO)3(h-C5H5)][fac-RuCl3(CO)3]," J. Organometal. Chem., 518, 197-202 (1996).
  • M. S. Morton, J. P. Selegue and A. Carrillo, "A Cyclopropenylidene Approach to Tricarbide Complexes: Synthesis and Structure of [M(CO)5{m2-C3(OCH2CH3)}Fe(CO)2(Cp)] (M = Cr, Mo, W)," Organometallics, 15, 4664-4666 (1996).
  • M. S. Meier, G.-W. Wang, R. C. Haddon, C. P. Brock, M. A. Lloyd and J. P. Selegue "Benzyne Adds Across a Closed 5-6 Ring Fusion in C70: Evidence for Bond Delocalization in Fullerenes," J. Am. Chem. Soc., 120, 2337-2342 (1998).
  • C. E. Wallace, J. P. Selegue and A. Carrillo, "Synthesis and Characterization of a 1,2-Dibenzoyl Ruthenocene and a Derived Pyridazine," Organometallics, 17, 3390-3393 (1998).
  • M. S. Morton and J. P. Selegue, "The Cyclo-C3 Ligand: Trimetallic Cyclopropenium Complexes of Group 6-8 Metals," J. Organomet. Chem., 578, 133-143 (1999).

 

 

A. Kiely. R. C. Haddon, M. S. Meier, J. P. Selegue, C. P. Brock, G.-W. Wang, and Y. Chen, "The First Structurally Characterized Homofullerene (Fulleroid)," J. Am. Chem. Soc., 121, 7971-7972 (1999).

X
Enter your link blue username.
Enter your link blue password.
Secure Login

This login is SSL protected

Loading