In this project supported by the Chemical Structure, Dynamics and Mechanisms Program of the Division of Chemistry, Professor Henning Meyer of the University of Georgia and his students will explore the dynamics of weak intermolecular forces in systems where at least one of the interacting members has an open electronic shell. The research will target complexes of nitric oxide (NO) with various molecular partners like N2, CO, CH4, C2H6 which are important in atmospheric chemistry or with partners like aromatic or hetero aromatic ring molecules which can contribute to the understanding of the biological functionality of NO. Their IR and near-IR vibrational and rotational spectra will be studied through constant photon energy sum (CONPHOENERS) scans, a technique developed in the Meyer laboratory or through action spectroscopy. As a new technique, ionization detected mm-wave absorption spectroscopy will be developed and employed to access transitions in the structural finger print region of the spectrum of these complexes. The experimental data will serve as benchmark to extend or stimulate high level ab initio calculations of interaction potentials towards larger open shell systems including lower symmetry configurations. This is especially important for the extension of dynamics or bound state calculations to include the full inter- and intramolecular coordinate space.
In addition to revealing information about the specific chemical systems targeted in the experimental studies, the research will advance our general understanding of molecular relaxation rates, which in turn are critical to the theoretical modeling of combustion environments or the modeling of chemical reactions in extreme environments not easily amenable to laboratory experiments. Results for the interaction of NO with specific aromatic or hetero-aromatic ring molecules will provide structural information about model sub-units involved in the binding and release of NO in its regulatory function recognized in structural biology. Since the research will involve the development of new spectroscopic tools (based on mm-wave and optical technology) which will bring together very different technical and scientific communities, it will provide unique opportunities for the training of the graduate students supported by this grant. In addition, the Meyer group will invite local high school teachers and undergraduate students (physics, chemistry and science majors) to participate in the proposed research, and thus experience experimental research at the frontiers of chemical physics and physical chemistry