CAS: Inhibiting Molecular Reorganization via Strategic Surface Binding

With support from the Chemical Structure, Dynamics & Mechanisms-B Program of the Chemistry Division, Professor Kenneth Hanson of the Department of Chemistry and Biochemistry at Florida State University seeks to understand and control molecular distortions by way of strategic surface binding. Molecules inherently change their structure (i.e., distort) in response to external stimuli such as light, heat, magnetic fields, etc. These distortions can have a debilitating impact on their properties and utility. The goal of this research is to use optical measurements to understand the role of surface binding in dictating molecular properties and ultimately use that knowledge to control reactivity, emission intensity, and stability of the molecular for subsequent use in more efficient catalysis, lighting, solar energy conversion, and more. Complementing these research efforts, this proposal introduces "Ask a Scientist Gaming" as a live streaming science outreach endeavor. Every other week, Professor Hanson hosts a different Ph.D. scientist to interface with the community and answer questions. The stream is free and available to individuals of all educational levels, socio-economic backgrounds, and identities. Molecules undergo a structural change to minimize the energy of the high-energy state generated via external stimuli such as pressure, oxidants/reductants, magnetic fields, or light. This process is intrinsic to all molecules but large changes in structure, especially those of transition metal coordination complexes, can have a debilitating impact on their properties and subsequent use in catalysis, lighting, solar energy conversion, and more. The central hypothesis for this project is that strategic surface binding (i.e., coordinating multiple, independent ligands to a surface) inhibits stimuli-included reorganization, resulting in increased excited state lifetimes, electrochemical reversibility, and geometric “trapping” of high energy species. Toward this end, the major goals of this work are to 1) synthesize a series of Cu(I) coordination complexes with systematic variation in the surface binding motif, 2) use spectroscopic and electrochemical techniques to determine the impact of surface binding on the molecules response to a stimulus, 3) geometrically trap coordinatively unsaturated and reactive Cu(I) photolysis products. 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.