Faculty Sponsor

James O'Brien

Final Abstract for URS Program

The electronic landscape of platinum containing molecules has been the focus of numerous spectroscopic studies in recent years, because of the difficulty in describing electronic structure theoretically due to electronic correlations and relativistic effects. A collective effort by spectroscopitsts and theoreticians to investigate the diatomic molecule platinum fluoride, PtF, has included research such as developing potential energy diagrams and performing analyses on rotational transitions with microwave spectroscopy. One group observed electronic transitions of PtF using laser vaporization/reaction with jet free expansion and laser induced spectroscopy. A highly effective method for observing and analyzing electronic transitions of small, metal-containing molecules like PtF is employing sensitive absorption techniques like Intracavity Laser Spectroscopy (ILS), with notable discoveries originating in the O’Brien lab. We employed an ILS technique to record the (0,0) vibrational band of the [15.3] Ω=3/2 – X 2Π 3/2 electronic transition of PtF. The PtF molecules were produced in a current regulated RF discharge operating at 0.30-0.80 A applied to a Pt-lined copper hollow cathode in 0.50-1.25 Torr of 1-5% SF6 in an Ar/He sputter gas mixture. The hollow cathode was placed within in the resonator cavity of a tunable DCM dye laser operating over the 14,500-16,500 cm-1 range, and path lengths of 0.2-2.0 km were utilized with the ILS method. The spectrum includes qualities of the major isotopologues of PtF including 194PtF, 195PtF, 196PtF, and 198PtF. A rotational analysis the electronic transition was performed using the spectral simulation software, PGOPHER. Excited state molecular constants were determined and lambda doubling was observed. Results will be presented and compared to theoretical discoveries to illustrate the symbiosis of experimental and computational studies in disentangling the complex electronic nature of platinum fluoride.

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