University of Vermont

College of Arts and Sciences

Department of Chemistry

UVM Chemistry Research: Stephen Waters

Rory Waterman

Rory Waterman

Rory Waterman, Ph.D., Associate Professor of Chemistry

  • Ph.D., University of Chicago, 2004
  • postdoctoral fellowship, University of California, Berkeley, CA (Miller Research Fellow), 2004-2006
  • Assistant Professor of Chemistry, University of Vermont, 2006-2012
  • Associate Professor of Chemistry, University of Vermont, 2012
  • Curriculum vitae
Area of expertise

synthetic inorganic chemistry, organometallic chemistry, catalysis

Contact Information

Email: Rory.Waterman@uvm.edu

Phone: (802) 656-0278

Office: Cook Rm A129

Website:
http://www.uvm.edu/~rwaterm1/

Awards

Rory Waterman received a Miller Institute for Basic Research in Science Research Fellowship (2004-2007). He was awarded a prestigious National Science Foundation CAREER Award (2008), a Research Corporation Cottrell Scholar Award (2009), and a Alfred P. Sloan Foundation Research Fellowship (2009).

Research

Research in the Waterman group applies the synthesis of novel inorganic and organometallic systems to define new reactivity and catalysis. Students will have the opportunity to prepare and fully characterize new complexes through a variety of spectroscopic techniques (e.g., NMR, IR, UV-vis, EPR), X-ray crystallography, and analytical methods. These complexes are frequently air-sensitive, and students learn to manipulate the complexes using high-vacuum and Schlenk techniques or in a glovebox. These complexes will target the catalysis of chemically important processes such as bond-forming and selective oxidation reactions.

A key reaction in element-element bond formation is dehydrocoupling, where two molecules with element-hydrogen bonds formally exchange E-H bonds to form E-E and H-H bonds. Dehydrocoupling is a very clean and efficient reaction taking often commercially available starting materials and providing element-element bonds with hydrogen (H2) as the only byproduct. However, for many elements this reaction is not facile, and a catalyst is needed. We have found that zirconium complexes supported by triamidoamine ligands such as (N3N = N(CH2CH2NSiMe3)33-) are effective for dehydrocoupling a range of primary and secondary phosphines. Through careful mechanistic study, we have determined that this catalysis proceeds via σ-bond metathesis steps as shown to the right.

Using this knowledge we are applying this system to catalyze other element-element bond formation reactions. Using the predictive power of our sigma-bond metathesis-based mechanism, we have recently demonstrated selective P-Si and P-Ge bond formation using our zirconium catalysts, and in a simple periodic analogy, we have shown, for the first time, that catalytic dehydrocoupling of arsines is possible. Our continued efforts in this area are directed at addressing questions in molecular synthesis, materials science, and energy.

Waterman Fig 1

A second project involves synthesis of new phosphorus-based ligand architectures to explore catalytic reactions. One reaction we are interested in is alpha-elimination, where a low-valent main group fragment (:ERm) is extruded from an early transition-metal (LnM) center such as zirconium or niobium, as depicted in the proposed catalytic cycle shown in the figure to the right. This reaction has seen limited attention in the literature, and we seek to exploit it for bond-forming catalysis.

Waterman Fig 2

We are also interested in developing alternative routes to accessing low-valent main-group fragments. A recent development in this area is our preparation of a phosphaalkene by insertion of an isocyanide into a zirconium-phosphorus bond. In this reaction we take a commercial available phosphorus source, a primary phosphine, and access a phosphinidene (":PR") fragment with perfect atom economy.

Waterman Fig. 3

Selected Publications

Roering, A. J.; Elrod, L. T.; Pagano, J. K.; Guillot, S. L.; Chan, S. M.; Tanski, J. M.; Waterman, R. A General, Zirconium-Mediated Synthesis of Phosphaalkenes with Liberation of Phosphaformamides. Dalton Trans, 2013, 42, 1159–1167.

Elrod, L. T.; Boxwala, H.; Haq, H.; Zhao, A. W.; Waterman, R. As–As Bond Formation via Reductive Elimination from a Zirconocene Bis(Dimesitylarsenide) Compound. Organometallics, 2012, 31, 5304–5207.

Wetherby, A. E.; Waterman, R. High Activity and Selectivity for Silane Dehydrocoupling by an Iridium Catalyst. ACS Catal., 2012, 2, 1404–1407.

Vaughan, B. A.; Arsenault, E. A.; Chan, S. M.; Waterman, R. Synthesis and Characterization of Zinc Complexes and Testing for Phosphine Dehydrocoupling Reactivity. J. Organomet. Chem. 2012, 696, 4327–4331.

Maddox, A. F.; Erickson, K. A.; Tanski, J. M.; Waterman, R. C–N Bond Formation via Ligand-Induced Nucleophilicity at a Coordinated Triamidoamine. Ligand Chem. Commun. 2011, 47, 11769–11771.

Ghebreab, M. B.; Newsham, D. K.; Waterman, R. Differences in the Stability of Zirconium(IV) Complexes Related to Catalytic Phosphine Dehydrocoupling Reactions. Dalton Trans. 2011, 40(30), 7683–7685 part of  d0 organometallics in catalysis special issue.

Leshinski, S. E.; Shalumova, T.; MacMillan, S. N.; Tanski, J. M.; Waterman, R. Insertion Reactions Involving a Triamidoamine-Supported Zirconium Complex. Dalton Trans., 2010, 39, 9073–9078.

Roering, A. J.; Leshinski, S. E.; Chan, S. M.; MacMillan, S. N.; Tanski, J. M.; Waterman, R. Insertion Reactions and Catalytic Hydrophosphination by Triamidoamine-Supported Zirconium Complexes. Organometallics 2010, 29, 2557–2565

Last modified March 08 2013 02:45 PM

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