Our research group intends to make a stong contribution to the fields of inorganic chemistry, nanoscale science and technology, and materials science. With this aim, standard Schlenk and glovebox techniques are employed to synthesize a variety of low-coordinate air and moisture sensi tive inorganic precursors. Characterization methods include multinuclear NMR, X-ray crystallography, FT-IR and UV/VIS spectroscopy, TGA/DTA, SEM, TEM and X-ray powder diffraction.

These investigations, while rooted in traditional aspects of chemistry, will often involve students in collaborations with an array of other scientists and engineers. Group members will have their own projects; however, each group member's research will have significant overlap with others in the group. As such, the students' depth of fundamental chemical principles will become augmented by exposure to a breadth of additional concepts. It is anticipated that such a combination of skills results in a fertile and creative environment for achievement of research goals. Therefore, students should frequently expand beyond the reaches of classical chemistry subjects, and embrace additional areas, as required, for the successful execution of a specific project.

Three components of our research plan will be further elaborated on in the following paragraphs:

The Design of Metal-Organic Complexes Utilizing a Synergistic Approach

In a number of metalloproteins hydrogen bonding (5 to 15 kcal/mol) is used in conjunction with metal-ligand covalent bonds to control activity within biomolecules. A current research challenge in synthetic inorganic chemistry is the incorporation of these types of interactions into well-defined metal compounds with the intension of developing enhanced catalytic and stoichiometric reactivity. Conversely, difficulties arise in synthetic systems because their structures are often flexible, so H-bonds form with various other species present, such as solvent molecules or counterions. These intermolecular hydrogen bonds are often unwanted and interfere with the desired function. Therefore, as in metalloproteins, synthetic complexes must have a combination of ligands placed within rigid frameworks located near the metal center(s) to ensure stable complex formation. Our research group utilizes a combination of novel set of ligands in conjunction with a vast array of metals throughout the Periodic Table to produce well designed multi-functional inorganic/organic hybrid systems. Students working in this area frequently expand beyond the reaches of classical chemistry subjects and embrace additional areas, as required, for the successful execution of a specific project. Standard Schlenk and glovebox techniques are employed to synthesize a variety of low-coordinate air and moisture sensitive inorganic complexes. Characterization methods include multinuclear NMR, X-ray crystallography, FT-IR and UV/vis spectroscopy, TGA/DTA, SEM, TEM, and X-ray powder diffraction. Such a combination of skills results in a fertile and creative environment for achievement of research goals

Gold Chemistry

In today's society, gold chemistry currently has an important role in fields such as electronics and medicine. However, there is still a current lack of understanding in the fundamental reaction chemistry of gold. The development of gold (I) chemistry is dominated by the viewpoint that gold is a prototypical soft Lewis acid, which forms its most stable complexes with soft Lewis bases. Accordingly, the synthesis of gold (I) complexes with hard Lewis bases such as oxygen, nitrogen, or carbon has been limited to a select number of examples. Such complexes have been described as intrinsically unstable, and therefore, have a pronounced tendency to either decompose to gold metal or aggregate into ill-defined clusters. Similar problems, although to a lesser extent, have been described for copper and silver. This instability has historically been described as a limitation to the development of gold chemistry. However, a few recent reports have hinted that a much richer field of coordination chemistry might be accessible. Therefore, in order to contribute to the understanding of this important metal, it is the goal of this research proposal to investigate the chemistry of previously "inaccessible" gold (I) alkyls, amides and alkoxides.

These novel complexes will be isolated as crystalline solids and characterized via solution and solid-state NMR, X-ray crystallograpy, FT-IR and UV/VIS spectroscopy. Throughout this investigation, the stability and reaction chemistry of these complexes will be investigated. It is the intention of this proposal to generate a large family of complexes in order to gain a true appreciation for the intrinsic stability of gold complexes.

Group 11 Metal-Organic Precursors

The semiconductor industry continues to undergo rapid techolonogical changes, especially in fabricating nanoscale integrated circuit (IC) devices. Smaller device features and a need for increased chip surface area have led to the use of multilevel interconnections to increase the functionality of IC devices. The search for better performance has led to consideration of materials such as Cu, Ag, and AU for use as interconnections. Historically, industry has relied on well established approaches, such as physical vapor deposition, to create such interconnects. However, due to consideratons such as cost and the nanoscale size regime the devices now have entered, interconnects fabricated via metal-organic chemical vapor deposition (MOCVD) and more recently nanocrystal deposition are increasingly favored. Currently, there is a lack of suitable Cu, Ag, and Au precursors that have attributes desired for MOCVD and nanocrystal synthesis.

This synthetic materials research project is suitable for both graduate and undergraduate students. For successful completion of this project, it will involve collaborations with an array of material scientists and engineers; augmenting the students' depth of fundamental chemical principles.

REPRESENTATIVE PUBLICATIONS (2005 to present)

1. Bunge, S. D.; Lance, J. M.; Bertke, J. A. "Synthesis, Structure, and Reactivity of Alkylzinc Complexes Stabilized with 1,1,3,3-Tetramethylguanidine" Organometallics 2007, 26, 6320-6328.

2. Cleland, T. L.; Bunge, S. D. "Synthesis and characterization of a series of zinc complexes stabilized by 1,1,3,3-tetraalkylguanidinate (TAG) ligands: [Zn(m-TAG){N(SiMe3)2]]2" Polyhedron 2007, 26, 5506-5512.

3. Bertke, J. A.; Bunge, S. D. "Stable analogs of the uranyl ion containing 1,1,3,3-Tetramethylguanidine" Dalton Trans. 2007, 4647-4649.

4. Laali, K. K.; Okazaki, T.; Bunge, S. D. "N-(Trifluoromethylsulfonyl)aryloxytrifluoromethylsulfoximines [ArO-SO(CF 3):NTf] and N-Aryltriflimides Ar-N(Tf) 2 by Thermal and Photolytic Dediazoniation of [ArN 2][BF 4] in [BMIM][Tf 2N] Ionic Liquid: Exploiting the Ambident Nucleophilic Character of a "Nonnucleophilic" Anion" J. Org. Chem. 2007, 72, 6758-6762.

5. Hannibal, L.; Bunge, S. D.; van Eldik, R.; Jacobsen, D. W.; Kratky, C.; Gruber, K.; Brasch, N. E. "X-ray structural characterization of imidazolylcobalamin and histidinylcobalamin: Cobalamin models for aquacobalamin bound to the B-12 transporter protein transcobalamin" Inorg. Chem. 2007, 46, 3613-3618.

6. Boyle, T. J.; Ottley, L. A. M.; Daniel-Taylor, S. D.; Tribby, L. J.; Bunge, S. D.; Costello, A. L.; Alam, T. M.; Gordon, J. C.; McCleskey, T. M. "Isostructural neo-pentoxide derivatives of group 3 and the lanthanide series metals for the production of Ln 2O 3 nanoparticles" Inorg. Chem. 2007, 46, 3705-3713.

7. Tandon, S. S.; Bunge, S. D.; Thompson, L. K. "A Tetradecanuclear Copper Dimeric Macrocyclic Complex with a Body-Centred Heptanuclear Core-Structure and Magnetism" Chemical Communications 2007, 798-800.

8. Mukherjee, R.; Dougan, B. A.; Fry, F. H.; Bunge, S. D.; Ziegler, C. J.; Brasch, N. E. "Structural and Spectroscopic Evidence for the Formation of Trinuclear and Tetranuclear Vanadium(III)/Carboxylate Complexes of Acetate and Related Derivatives in Aqueous Solution" Inorganic Chemistry 2007, 46, 1575-1585.

9. Yang, H. B.; Hawkridge, A. M.; Huang, S. P. D.; Das, N.; Bunge, S. D.; Muddiman, D. C.; Stang, P. J. "Coordination-Driven Self-Assembly of Metallodendrimers Possessing Well-Defined and Controllable Cavities as Cores" Journal of the American Chemical Society 2007, 129, 2120-2129.

10. Boyle, T. J.; Sewell, R. M.; Ottley, L. A. M.; Pratt, H. D.; Quintana, C. J.; Bunge, S. D. "Controlled Synthesis of a Structurally Characterized Family of Sterically Constrained Heterocyclic Alkoxy-Modified Titanium Alkoxides" Inorganic Chemistry 2007, 46, 1825-1835.

11. Boyle, T. J.; Tribby, L. J.; Bunge, S. D. "Synthesis and Structural Characterization of a Series of Carboxylic Acid Modified Cerium(III) Alkoxides" European Journal of Inorganic Chemistry 2006, 4553-4563.

12. Gerung, H.; Boyle, T. J.; Tribby, L. J.; Bunge, S. D.; Brinker, C. J.; Han, S. M. " Solution Synthesis of Germanium Nanowires Using a Ge 2+ Alkoxide Precursor." Journal of the American Chemical Society 2006, 128, 5244-5250.

13. Gerung, H.; Bunge, S. D.; Boyle, T. J.; Brinker, C. J.; Han, S. M. "Anhydrous solution synthesis of germanium nanocrystals from the germanium(II) precursor Ge[N(SiMe 3) 2] 2." Chemical Communications 2005, 1914-1916.

14. Fan, H.; Leve, E. W.; Scullin, C.; Gabaldon, J.; Tallant, D.; Bunge, S.; Boyle, T.; Wilson, M. C.; Brinker, C. J. "Surfactant-Assisted Synthesis of Water-Soluble and Biocompatible Semiconductor Quantum Dot Micelles." Nano Letters 2005, 5, 645-648.

15. Boyle, T. J.; Tribby, L. J.; Alam, T. M.; Bunge, S. D.; Holland, G. P. "Catechol derivatives of Group 4 and 5 compounds." Polyhedron 2005, 24, 1143-1152.

16. Boyle, T. J.; Alam, T. M.; Bunge, S. D.; Segall, J. M.; Avilucea, G. R.; Tissot, R. G.; Rodriguez, M. A. "Tetrahydrofurfuryloxide Derivatives of Alkyl Aluminum Species." Organometallics 2005, 24, 731-737.

17. Boyle, T. J.; Bunge, S. D.; Alam, T. M.; Holland, G. P.; Headley, T. J.; Avilucea, G. "Cadmium Amido Alkoxide and Alkoxide Precursors for the Synthesis of Nanocrystalline CdE (E = S, Se, Te)." Inorganic Chemistry 2005, 44, 1309-1318.

18. Boyle, T. J.; Bunge, S. D.; Clem, P. G.; Richardson, J.; Dawley, J. T.; Ottley, L. A. M.; Rodriguez, M. A.; Tuttle, B. A.; Avilucea, G. R.; Tissot, R. G. "Synthesis and Characterization of a Family of Structurally Characterized Dysprosium Alkoxides for Improved Fatigue-Resistance Characteristics of PDyZT Thin Films." Inorganic Chemistry 2005, 44, 1588-1600.

PATENTS

(1) Scott D. Bunge and Timothy J. Boyle, “Synthesis of Metal Nanoparticles” ( USA), 2005 7pp.

Last Updated: 20 March 2008