The mineral element phosphorus is used in many industrial and household chemicals, from fertilizers to pesticides to detergents.
The problem? Getting that phosphorus into those products from a molecular standpoint is both hazardous and expensive, and requires the use of chlorine, itself a corrosive chemical.
But MIT researchers have developed a way to streamline the process and cut out the chlorine altogether — sparing the health of industrial workers who handle chlorine, as well as the environment.
Researchers Christopher Cummins and Daniel Tofan discovered a simple way to attach phosphorus to organic compounds: split it with ultraviolet light.
For most industrial uses, phosphorus must be attached one atom at a time, in two steps: first, replace three of the atoms in a purified form of the naturally-occurring “white phosphorous” molecule with chlorine; second, displace the chlorine atoms with organic molecules.
Voila: the necessary compounds to make industrial and household chemicals.
Unfortunately, using chlorine as a middleman is both wasteful and dangerous.
Drawing inspiration from a paper published in 1937, the researchers attempted using UV light to break apart the white phosphorous molecule. The trick: do it in the presence of organic molecules that have an unsaturated carbon-carbon bond, which allows them to form new bonds with other atoms.
After 12 hours of UV exposure, a compound called a tetra-organo diphosphane had formed: two atoms of phosphorus attached to two organic molecules.
The result suggests that an immediate bond between phosphorous and organic compounds is possible, opening the door for more ways to use UV light to synthesize compounds.
For now, the development is only reproducible at lab scale. The researchers’ next hurdle is to scale the process up to levels that can sustain mass production of phosphorous compounds.
Their research was published in the Aug. 26 edition of Angewandte Chemie.
Photo: Chlorinated acid-wash jeans.
