This award in the Inorganic, Bioinorganic, and Organometallic Chemistry Program provides continued support to Dr. James N. Demas of the Chemistry Department, University of Virginia, for research on use of luminescent transition metal complexes for sensors and molecular probes. Dr. Benjamin DeGraff of James Madison University will collaborate on this research which will involve undergraduate as well as graduate and postdoctoral students. New complexes containing Ru, Re, Os, and Ir will be synthesized and tested as sensors for oxygen gas, carbon dioxide, and acidity. Heterogeneous behavior in solution (e.g., soluble polymers, vesicles) and in solid supports (e.g., polymers, silicas) will be examined in order to understand microheterogeneous interactions that affect sensor probe performance. Many methods will be used to determine the photophysics and photochemistry of the new systems and how they are perturbed by interaction with surfaces, including time resolved emission spectroscopy, transition absorption spectroscopy, steady-state luminescence, global luminescence decay analysis, gas solubility and oxygen diffusion measurements, dynamic polarization anistropy measurements, solvatochromic probes, temperature dependence studies, crystallography and molecular modeling. Oxygen, carbon dioxide, and acidity levels change during many common biological and industrial processes. By monitoring the levels of these chemicals, the amount of reaction products or impurities can be determined. The goal of this research is to develop stable, durable sensors that could be used in many industrial, medical, and environmental applications. The luminescent compounds investigated are potentially useful in biomedical monitoring, fluoroimmunoassay, industrial process control, wind tunnel sensors, biological oxygen demand, bioreactors, and environmental monitoring.
