RUI: An Experimental and Theoretical Study of Stannylcarbenes

Colby College, Waterville ME

Investigators

Abstract

In this RUI project, funded by the Chemical Structure, Dynamics & Mechanism B Program of the Chemistry Division, Professor Thamattoor of the Department of Chemistry at Colby College, and his team of undergraduate students, are investigating tin-substituted carbenes by experimental and theoretical methods. Carbenes are highly reactive chemical species which feature a carbon that has only two bonds instead of the usual four. Carbenes that are coordinated with a variety of metals have played important roles in the production of commercially valuable materials. However, much less is known about carbenes in which one or both bonds of the carbon are attached to a metal. This research aims to address this gap in knowledge. This project also includes efforts to persuade high school students to consider STEM (Science, Technology, Engineering and Mathematics) disciplines in college. Professor Thamattoor provides research opportunities to high school students in the laboratory. The group also works with teachers in the local grade schools to deliver quality instruction in STEM subjects. In recognition of the importance of global scientific cooperation, undergraduate students are provided with research opportunities in international laboratories. Metal-coordinated carbene complexes are well known compounds that have had a transformative impact on synthesis and catalysis. In contrast, very little is known about uncomplexed metal-substituted carbenes, where the metal is one (or both) of the substituents on the divalent carbon. Through this RUI (Research at Undergraduate Institutions) grant, a comprehensive set of projects is being undertaken to study stannylcarbenes. These intermediates are generated photochemically from new precursors based on cyclopropanated phenanthrene and indan systems. The structure and reactivity of these tin-substitued carbenes are investigated experimentally by steady state photolysis, electron paramagnetic resonance spectroscopy, matrix isolation spectroscopy, and time-resolved laser flash photolysis, as well as by modern computational methods. In addition, several initiatives to create international research opportunities for undergraduates, and to promote high-quality STEM education for grade K -12 students in area schools are being pursued. The integrated research and outreach activities enrich the undergraduate research experience at Colby College, and also serve the local community. 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.