Green Chemistry of White Phosphorus
Many phosphorus chemicals (bulk and fine) are made from white phosphorus, but indirectly via phosphorus trichloride. Manufacture of PCl3 requires chlorine gas, which is highly toxic and corrosive, possesses high environmental risk and is ‘energy expensive’. Halogenation of white phosphorus to PCl3 serves essentially as a means of moderating the reactivity and often no halogen is retained in the resulting products. Therefore, it is highly desirable to search for other means of moderating the reactivity of white phosphorus in order to achieve energy and atom efficient transformations into high value chemicals, without the formation of halide waste. Ideally the new reactivity moderators replacing halogenation will be inexpensive, non-toxic, highly specific and highly efficient (therefore only catalytic amounts will be needed).