In this project funded by the Chemical Synthesis Program of the Chemistry Division, Professor Guy Bertrand of the Chemistry and Biochemistry Department at the University of California - San Diego, will prepare environmentally benign building blocks for the synthesis of phosphorus derivatives. Phosphorus is vital not only for food production but also for other agricultural commodities such as ethanol, biofuels, and any biorenewable chemicals. Phosphorus availability is a looming crisis even more severe than dwindling supplies of fossil fuels, simply because no alternative for this element exists. The ultimate goal of this project is to induce a shift in current phosphorus research, and hopefully industry, toward more sustainable practices. The aim is to circumvent traditional phosphorus starting materials, such as PCl3, whose transformation into the desired chemicals produces an enormous amount of waste as well as being extremely energy-inefficient. The laboratory of the PI is a joint venture between UCSD and the French CNRS. It serves to promote the exchange of undergraduates and graduates between UCSD and European Universities.
PCl3 features a phosphorus center, which can be viewed as a P3+ synthetic equivalent. The aim of this project is to develop stable sustainable "P¯" building blocks, including PN2¯ and P3¯, phosphorus-containing analogues of the azide anion (N3¯). Through reaction with electrophiles (E+), these building blocks will lead to highly reactive phosphinidenes (E-P), including their room temperature stable version. This monocoordinated phosphorus species, isoelectronic with carbenes, will readily be transformed into a broad range of phosphorus compounds, including artificial allotropes of phosphorus. The "P¯" synthetic equivalents will also be used for the preparation of RNP2 and RP3, which are di- and tri-phosphorus analogues of azido derivatives, as well as R2C=P2 which are diphosphorus analogues of diazo derivatives. These compounds will not only act as 1,3-dipoles allowing for the preparation of a variety of phosphorus heterocycles, but will also be generators of the highly reactive dinuclear P2, which will be chemically trapped. The broader impacts of this work include potential societal benefits, and since this project is at the interface between physical, organic, inorganic and organometallic chemistry, it is well suited to the education of chemists at all levels. This project will contribute to the education of four Graduate Students, three of whom are minorities, and the first of their family to earn an undergraduate degree.
