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Name Mr. Kai Lister
Organization University of North Florida
Type Poster
Topic Physical Chemistry
Title

VELOCITY MAP IMAGING EXPERIMENTS FOR FUNDAMENTAL DETAILS OF THE POTENTIAL ENERGY SURFACE OF NITRIC OXIDE

Author(s)

Kai Lister, Jennifer E. Ruliffson, Melanie White, and Joshua J. Melko

Author Location(s)

Department of Chemistry, University of North Florida, Jacksonville, FL 32224.

Abstract

We conducted a study to map the potential energy surface and measure the electron affinity of nitric oxide through velocity map imaging and computational methods. A custom mass spectrometer was used to mass select a stream of nitric oxide anions created in situ from nitrous oxide. This stream was impacted with the second-harmonic of a Nd:YAG laser. Photodetached electrons were captured on a phosphor screen, and the two-dimensional image was reconstituted into a three-dimensional molecular orbital. To supplement experimental data, a computational study was performed using ezSpectrum software to predict the photoelectron spectrum at different source ion temperatures. This software calculates the Franck-Condon factors from the equilibrium geometry, harmonic frequencies, and normal mode vectors obtained from Gaussian 09 optimizations. Intensities of the transitions between different vibrational states of the anion and neutral electronic states are used to reconstruct a photoelectron spectrum. These theoretical spectra are produced using ion temperature as an adjustable parameter until the experimental spectrum is reproduced, thus establishing the ion temperature within our apparatus. Collectively, these studies identify the electron affinity, bond energy, and vibrational details of nitric oxide, yielding information applicable to gas phase reactivity and energetics of nitric oxide in Earth’s atmosphere.