Collaborative Research: Spectroscopic Studies of Metal-Containing Diatomics and Field Shift Effects

University Of Missouri-Saint Louis, Saint Louis MO

Investigators

Abstract

This grant from the Chemical Structure, Dynamics, and Mechanisms-A program supports the collaborative research projects of Professor Leah O’Brien at Southern Illinois University Edwardsville and Professors James O’Brien and Jack Harms at the University of Missouri-St. Louis. They use high-resolution electronic spectroscopy to investigate small, metal-containing molecules. These studies help to explain the way that metal ions are modified when they form chemical bonds, providing valuable insight into the nature of larger metal-containing molecules that are difficult to study directly. Research participants acquire a wide range of skills through a combination of activities, including development of instrumentation, data collection using light-absorption and/or emission spectroscopic methods, and digital data analysis. This project continues an inter-institutional collaboration of faculty and students at a primarily undergraduate institution and a major research university. It enhances the research infrastructure at both universities and develops students and faculty with skills in contemporary spectroscopy and instrument development. The project also contains an outreach program that allows talented high school students to participate in the research. The O'Brien groups use intracavity laser absorption spectroscopy combined with high resolution Fourier transform detection (ILS-FTS). The plasma discharge techniques to produce the molecules of interest employ direct current (DC) and radio frequency (RF) pulsed DC plasma generators as used in industry. The spectra are rotationally analyzed to obtain new and/or improved molecular constants (e.g., transition energy, rotational and vibrational constants, angular momentum coupling constants, mass-independent parameters for species with multiple isotopologues). These constants are used to develop energy level diagrams and potential energy curves for molecules and may even provide a glimpse of the metal nucleus through the electronic field-shift effect, which was recently characterized for platinum-containing molecules. These parameters enable comparison of the experimental results with on-going, high-level computational results from colleague Prof. Wenli Zou for these small molecules. This work enhances our understanding of metal-ligand interactions, periodic trends for metal-ligand binding, and provides insight on metal-catalyzed reactions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.