Our research efforts lie at the interface of synthetic and physical inorganic chemistry with particular emphasis placed on molecular chemistry of consequence to renewable energy. Using the guiding principles of multielectron redox catalysis and proton-coupled electron transfer we seek to develop schemes for the activation of small molecule substrates including CO₂, H₂, H₂O and O₂. We make use of expertise in the areas of organic and inorganic synthesis, organometallic chemistry, electrochemistry, photochemistry and catalysis to accomplish these goals. Our group is also initiating work focused on developing fluorescent architectures that respond to organic neurotransmitters. This work has applications in molecular imaging and the elucidation of the chemical mechanisms that control synaptic plasticity.

Current Research
Electrocatalysts for the reduction of CO2 to energy rich fuels. The use and implementation of renewable energy sources on a large scale requires the efficient storage of electron equivalents. The development of methods to store energy via the generation of chemical fuels in a carbon-neutral fashion represents one strategy to address this issue. A major thrust of our research program is dedicated to the catalytic conversion of stable substrates such as CO₂ and H₂O to versatile, energy-rich fuels via energetically uphill chemical processes.

Such a cycle is illustrated to the right. The reduction of CO₂ to give CO and H2O is an energy storing process that can be coupled to the water-gas shift (WGS) reaction to produce hydrogen. In this way, the electrochemical reduction of CO₂ to CO provides a feasible route to the renewable generation of hydrogen, when the energy input for the endergonic reaction is provided by the capture of solar energy with a photovoltaic device.

The success of such an energy storing cycle is dependent on the development of molecular catalysts that selectively reduce CO₂ to CO at low overpotential. The development of such systems is one of the fundamental challenges in renewable energy research today and is being actively pursued in our laboratory. Our group is also designing and synthesizing a new class of porphyrinoid macrocycles possessing a multielectron photochemistry that is well suited to small molecule activation schemes of consequence to energy storage.

Molecular imaging of small molecule neurotransmitters. Although neurotransmission is a chemical process, the study of signal transduction in the CNS has traditionally been carried out by neurobiologists and neurophysiologists due to the specialization required for such investigations. Elucidating the chemical mechanisms that drive neurotransmission poses a grand challenge for understanding the neurological cascades that comprise thought, learning and memory. Before this ultimate goal can be realized a molecular toolkit is needed to visualize the chemical species responsible for signal transmission in the CNS and brain. Accordingly, we seek to develop fluorescent constructs for the selective detection and spatiotemporal visualization of small molecule neurotransmitters including amino acids and monoamines in vivo.