Synthesis of d- and p-Block Element Molecules, Reagents, and Precursors

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Funded by the Chemical Synthesis Program of the Chemistry Division, Professor Christopher Cummins of the Massachusetts Institute of Technology leads a project aimed at producing new kinds of chemical compounds containing phosphorus. Phosphorus is a required component of fertilizers, semiconductors, and catalysts. Cummins is inventing new compounds of phosphorus that are sufficiently stable to be handled in the laboratory but reactive enough that they can serve as ingredients to useful products. The group is developing "spring-loaded" compounds that deliver very reactive molecules that contain phosphorus. These new entities are combined with organic compounds to give new and often unexpected products. Some of the new reactive phosphorus compounds are short-lived, being stable only for seconds at low temperatures. It is speculated that these short-lived compounds occur in the outer space, where even highly reactive molecules are stable. Thus Professor Cummins aims to correlate data from his laboratory with astronomical measurements. Overall, the research is highly collaborative, involving scientists in academia, national laboratories, and industry. The project provides hands-on training for graduate and undergraduate students who are exposed to multiple tools and ways of thinking about chemistry. Furthermore, the research connects and cross fertilizes multiple areas, including radioastronomy, microelectronics, and chemistry. In addition to traditional publishing venues, the Cummins group produces videos of synthetic procedures. These videos are posted on YouTube to facilitate adoption of protocols by other researchers and to provide the public with a window into the practice of synthetic chemistry. In this way, this research reaches well beyond the laboratory, inspiring young aspiring scientists to develop technical skills. Funded by the Chemical Synthesis program of the Chemistry Division, Professor Christopher Cummins of the Massachusetts Institute of Technology leads a project aimed at producing new kinds of organophosphorus compounds. This project focuses on the development of molecular precursors resulting from the expulsion of a neutral leaving group, such as anthracene, upon irradiation or thermal activation. This strategies provide access to reactive intermediates such as phosphinidenes or phosphacyclobutadienes. The reactive intermediate can be transferred to a suitable acceptor molecule for reactions carried out in solution, or released into the gas phase to enable studies by molecular beam mass spectrometry, microwave spectroscopy, and laser-induced fluorescence. Isolated reaction products are characterized by multinuclear NMR spectroscopy and X-ray crystallography. The experimental work is complemented by quantum chemical calculations designed to reveal details of bonding and to elucidate reaction mechanisms by potential energy surface explorations. The work is broadly impactful because of the centrality of phosphorus in everyday life, e.g. in fertilizers, microelectronics, and catalysis. 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.