Transition metal complexes have many properties
which can be used to gain insight into fundamental processes and
into more applied problems including catalysis and solar energy conversion.
Of primary concern to my group are studies of
- Electron transfer
- Photochemistry and excited states and
how they can be used in energy conversion processes
- Catalysts
for oxidation and reduction in solution and attached to surfaces,
polymers, or semi-conductor electrodes
- Chemical models for enzyme-catalyzed
reactions such as water oxidation and nitrite reduction
- Preparation
and characterization of metal complex containing polymers
having interesting excited state or catalytic properties
- Photochemical
and catalytic properties of thin polymeric films on electrodes
- Molecular assemblies for studies in artificial photosynthesis
and molecular devices.
We want to find out at the molecular level how
electron transfer occurs. With this knowledge in hand, can we learn
how to control the direction and rate of electron flow in molecular
assemblies? Can we prepare molecular assemblies that have the functional
properties of the reaction center of photosynthesis? Can the equivalent
of a p/n junction at the molecular level be created by combining
synthesis and transient laser spectroscopic techniques and electrochemistry
to monitor electron transfer?
The excited states
of metal complexes are being investigated by emission spectroscopy
and laser photolysis with uv-visible, IR, and resonance Raman monitoring.
These studies are leading to a clearer understanding of the molecular
properties that control excited state decay and photochemistry. These
complexes provide building blocks for preparing molecular assemblies
for the study of long range electron and energy transfer.
We have prepared
a series of ruthenium and osmium complexes which are catalysts for
oxidation or reduction of many inorganic or organic molecules. These
reactions include epoxidation and oxidation of alcohols to ketones
or aldehydes. We study the mechanisms of these reactions and others
such as reduction of nitrite and dinitrogen and the oxidation of
water to dioxygen.
Methods have been
developed for incorporating metal complexes into thin polymeric films
on electrodes. We are investigating the fabrication of controlled
microstructures within these films by electrochemistry and photochemistry.
Images can be created by using masking techniques and size-selective
membranes by using photolysis to create molecular voids.
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