Research in the Waterman Group addresses
problems in synthesis, catalysis, materials, and energy
through the application of organometallic systems. These
efforts are directed at the discovery of new synthetic methods
in the main group, the preparation of novel materials, and
development of efficient or "green" syntheses through
I. BOND-FORMING CATALYSIS
We have been investigating methods to catalytically form bonds
between main group elements. In particular, we have been
looking at generating bonds to phosphorus. There is a rich
synthetic chemistry associated with phosphorus; however,
methods to generate those bonds catalytically are sparse.
To meet this end, we are applying early transition-metal
complexes in dehydrocoupling reactions. Dehydrocoupling
catalysis effectively exchanges element-hydrogen bonds from
two molecules to form an element-element bond with liberation
of hydrogen. We have recently demonstrated that triamidoamine
complexes of zirconium are effective catalysts for the
dehydrocoupling of phosphines. Further, we found that the
catalysis appears to rely on sigma-bond metathesis steps for
P-P bond formation (right). Applying this knowledge, we have
already demonstrated selective P-Si and P-Ge bond-forming
Our main goal in developing these new methods is to use this
kind of catalysis in the synthesis of novel materials that may
exhibit unique properties.
II. CHEMICAL STORAGE OF HYDROGEN
Simple main-group molecules are being considered as method to
storing hydrogen because of the inherent difficulties
associated with pressurization, liquefaction, and
physisorption. We are applying our knowledge of
dehydrocoupling catalysis to develop an understanding of how
hydrogen released from simple inorganic molecules such as
amine-boranes with the broader goal of developing strategies
to reversibly liberate hydrogen from these molecules.
III. SYNTHESIS INVOLVING LOW-VALENT FRAGMENTS
Another route we are exploring to forming element-element
bonds is through the generation of low-valent fragments.
Molecular precursors to low valent fragments are known for
lighter elements such as carbon or nitrogen. This is not true
for the heavier main-group elements. We have been
investigating alpha-elimination, or the extrusion of a
low-valent fragment from a transition-metal, as one possible
route to these kind of species. Recently, we have discovered
the first instance of catalytic alpha-arsinidene elimination.
We are also interested in discovering innovative routes to
accessing low-valent main-group fragments. A recent
development in this area is our preparation of a phosphaalkene
(molecule with a P=C bond) by insertion of an isocyanide into
a zirconium-phosphorus bond. In this reaction, we take a
commercially available phosphorus source, a primary phosphine,
and effectively access a phosphinidene ("PR") fragment with
perfect atom economy.
IV. CARBON DIOXIDE ACTIVATION
In collaboration with Rick Kemp
at UNM/Sandia National
Laboratories and Bill Geiger
at UVM, we have been
developing zinc and tin complexes to coordinate carbon dioxide
and facilitate electrochemical reduction.
Research in the Waterman Group is/has been generously
supported by a number of agencies through grants and awards.
- U. S. National Science Foundtion (grant number
- Research Corporation for Science Advancement through a
Cottrell Scholar Award to R. W.
- Alfred P. Solan Foundation through a Research Fellowship
to R. W.
- subcontractor to LDRD award at Sandia National
- American Chemical Society Petroleum Research Fund (grant
- Vermont Space Grant Consortium (Graduate Research
Assistantship for Analese Maddox)
- Project SEED (summer funding for high school students)
- Univerity of Vermont (start-up funds)
Last modified March 29, 2013 7:55 AM