Early Metal Mediated Chemistry of the Group 15 Elements

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Dr. Christopher C. Cummins, Chemistry Department, Massachusetts Institute of Technology, is supported by the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Division for the development of new reactions that utilize nitrogen, phosphorus, and arsenic atoms derived directly from the elements. Using complexes in which a nitrogen, phosphorus, or arsenic is triply bonded to a niobium or molybdenum, atom transfer will be used to synthesize organic nitrogen, phosphorus, and arsenic compounds. Routes will be developed for the preparation of reactive diatomic molecules P2, PN, and AsP. Preliminary results suggest that the P2 molecule can be stabilized transiently by binding to the M(CO)5 (M = Cr, Mo, or W) fragment, and that the simple complex (P2)W(CO)5 can be cleanly trapped by organic dienes (double Diels-Alder reactivity of the P?ßP bond), by metal complexes, or by metal-ligand multiple bonds. Similar reactions will be explored with PN and AsP. The most abundant element in the earth's atmosphere is nitrogen. While nature is able to utilize atmospheric nitrogen in biological systems, modern chemical science is still seeking technologies for the economical usage of elemental nitrogen. This project grows from the recent discovery of molybdenum and niobium compounds that can cleave the nitrogen-nitrogen bond in dinitrogen under mild conditions. In order to utilize this chemistry, the nitrogen atoms derived from metal assisted dinitrogen cleavage will be used to prepare organic nitrogen compounds. In addition, related processes will be devised to use phosphorus and arsenic atoms derived from elemental phosphorus and arsenic, respectively. These results will result in new ways to prepare important classes of organic and inorganic arsenic, phosphorus, and nitrogen compounds. In addition to the scientific results, this project will provide training to a diverse group of undergraduate, graduate, postdoctoral, and visiting senior scientists.