High Resolution Spectroscopy of Reactive Chemical Intermediates and Related Studies

Ohio State University, The, Columbus OH

Investigators

Abstract

In this project supported by the Chemical Structure, Dynamics and Mechanisms Program of the Chemistry Division, Prof. Terry A. Miller of Ohio State University and his research group will utilize high resolution cavity ring-down spectroscopy (HR-CRDS) to obtain and analyze the spectra of a number of reactive chemical intermediates relevant to tropospheric chemistry, including organic peroxy radicals, nitrate radicals, and hydroxy alkoxy radicals. A new technique developed in the Miller laboratory called far-infrared/mid-infrared resonance enhanced multiphoton ionization double-resonance spectroscopy (FIR/MIR-REMPI-DRS) will be used to extend spectral studies to longer wavelengths and obtain high resolution spectra of species like carbon chains (relevant to astrochemistry) and biologically relevant molecules such as amino acids. These studies will provide diagnostic markers for radicals and other molecules that are important in combustion and atmospheric chemistry, and extend high resolution spectroscopy to low frequency regions of the spectrum that can provide characteristic information on large molecules. The analyses of the spectra will also provide precise molecular parameters that can serve as experimental ?gold standards? to guide and benchmark electronic structure calculations. The broader scientific impacts of the proposed studies include valuable spectral data and diagnostics relevant to tropospheric chemistry, astrochemistry, and biochemistry. In addition, the young researchers working on these projects will acquire excellent training in physical chemistry - gaining invaluable experience in both sophisticated experimental and theoretical methods. Prof. Miller will continue the development of research-based graduate courses that emphasize the broad applications of molecular spectroscopy, as well as develop a new module on the same theme appropriate to introductory chemistry courses.