2012 Summer Symposium Program - Middlebury College

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Peter Hetzler ‘14
Major: CHEM
Dr. Brendan ’94 and Mrs. Tristan
Phifer O’Leary ’95
Mark Isbell ‘14
Major: CHEM
Dr. Brendan ’94 and Mrs. Tristan
Phifer O’Leary ’95
Rachel Fowler ‘14
Major: NSCI
National Science Foundation
(Byers)
Jeff Byers
Philip Battell & Sarah Stewart
Professor of Chemistry and
Biochemistry
Middlebury Summer Research Symposium 2012
The Production of Molecular Wires through
Acyclic Diene Metathesis (ADMET) and Ring
Opening Metathesis Polymerization (ROMP) of
Chromium Organometallic Arenes
Peter Hetzler, Mark Isbell, Rachel Fowler and Jeff Byers
Department of Chemistry and Biochemistry, Middlebury College, Middlebury VT 05753
To create an organic electrically conductive wire we chose chromium complexes
as our study subject due to their ease of production and handling along with their
interesting innate chemical properties. For example, the addition of the chromium
to an organic backbone decreases the π-π* gap causing the normally colorless
compound to turn yellow, a key indication of a successful reaction. This implies the
effect of resonance is increased, effectively enhancing conjugation and conduction
of the molecule as a whole. Through Grubb’s Catalyst-facilitated Acyclic Diene
Metathesis (ADMET) and Ring Opening Metathesis Polymerization (ROMP), we
attempted the polymerization of several chromium organometallic monomers. Each
monomer was produced through a de-novo synthesis involving mainly benzene and
indole derivatives as starting materials. We have successfully synthesized six different
organometallic chromium compounds, and studies of their successful polymerization
and isolation are still ongoing. We have, however, managed to dimerize a monomer
with a tert-butyl styrene backbone, offering proof of principle that the Grubbs can
successfully catalyze the polymerization of a chromium complex. The results of this
research could show that ADMET polymerization of arene chromium complexes is
feasible in relatively straightforward and cost-effective ways. This will open a route
to a family of potentially useful and interesting polymers. If successful, we could,
in theory, fine-tune a molecular wire to the exact specifications needed for distinct
applications.