Our research is focused on organic materials. We are interested in using the
tools of organic synthesis, physical organic chemistry, and materials science
to design, construct, and study relatively large (nanoscale) organic molecules
with properties relevant to supramolecular and molecular electronics.
We are particularly interested in compounds that exhibit unusual
conformational behavior, self-assembly into more-complex architectures,
or functional electronic structures. Typically, the molecules we target are
synthetically challenging, often because of the very structural features
we hope to exploit. Consequently, most of our time is spent
as synthetic organic chemists. However, every compound we target
is chosen for particular functional properties which
we then characterize by various spectroscopies and
other techniques. Further characterization of our materials is done in
collaboration with various other groups at
Miami and elsewhere.
Although the techniques we employ vary somewhat by project, all students
in the Hartley group will get extensive training in
organic synthesis, including the execution of oxygen- and
moisture-sensitive reactions; structure elucidation by spectroscopic
techniques (e.g., NMR); and basic UV/Vis and fluorescence spectroscopy.
In addition, our group also makes use of polarized microscopy and
differential scanning calorimetry (for liquid crystals); gel permeation
chromatography; and computational chemistry.
There are presently two major systems that we are working on:
- ortho-Phenylenes
- Cross-Conjugated Nanoarchitectures
ortho-Phenylenes
The focus of this project is the development of ortho-phenylenes
as a new and unusual class of conjugated organic oligomers. These materials,
just a chain of aromatic rings connected through the ortho positions,
represent a fundamental class of conjugated polymer but have received
very little attention. We have recently
developed a synthetic approach to monodisperse ortho-phenylene oligomers.
We have been able to show that conjugation extends remarkably far along the
ortho-phenylene backbone, although its magnitude is attenuated compared to
most other linearly conjugated systems. Our findings have led us to
hypothesize that the ortho-phenylenes may adopt a well-defined helical
conformation in solution. We are currently working to better understand the
conformational behavior of these structures, and also to probe charge
and energy transfer through their dense, twisted backbones. Ultimately,
we hope to use ortho-phenylenes to study and exploit through-space electronic
interactions between chromophores, for applications in supramolecular and single-molecule
electronics.
Collaborators
Currently, we have active collaboration with the following scientists
and their groups:
