Research Interests

Inorganic and Bioinorganic Chemistry

 

Our research is directed towards an understanding of the mechanisms of reactions of transition metal complexes, including those complexes which occur in nature.

Iron is an essential element for all living cells. A major focus of our research is on the kinetics and mechanism of selective iron chelation, molecular recognition, membrane transport and iron release. These are chemical processes involved in the acquisition of iron by single cells and higher organisms. We are investigating the kinetics and mechanisms of iron complexation by various model ligands and natural iron carriers in aqueous solution, and on the surface of micelles, to mimic metal transport across a cell membrane. We are also interested in molecular recognition of iron complexes by ionophore hosts through second-sphere complexation (e.g. I). The reactivity of these supramolecular assemblies and their ability to be selectively transported through a liquid membrane is under investigation in our laboratories.

As a part of our active interest in iron mobility, transport and storage, we are investigating the coordination chemistry of mammalian and bacterial transferrin. As an extension of this work we are interested in the role of iron in human health and disease.

The mechanism for communication between allosteric sites is an important problem in biological systems. We are interested in cooperativity in electron transfer reactions involving metal centers. Our laboratory is engaged in a spectroelectrochemical investigation of cooperative electron transfer in various hemoglobin molecules, including human, fish, and genetically engineered hemoglobins. This enables us to investigate cooperativity mechanisms in well characterized proteins with four iron centers and to relate our results to cooperativity in O₂ transport and NO transport.

We are also interested in the electrochemistry of selected redox enzymes. We have developed immobilization methods to prepare enzyme electrodes which may be used as amperometric biosensors. These sensors take advantage of the selectivity and sensitivity of the immobilized enzyme for specific analytes.