Teflon is popular, used on everything from cooking pans to armor-piercing bullets, but it has a waste byproduct, fluoroform, which has to be stored by chemical companies because it has an estimated global warming potential 11,700 times higher than carbon dioxide.
USC scientists are patenting a way to use the ozone-destroying greenhouse gas and transform it into reagents for producing pharmaceuticals. G.K. Surya Prakash , a professor of chemistry at USC and director of the USC Loker Hydrocarbon Research Institute, describes fluorine as "the kingpin of drug discovery." About 20 to 25 percent of drugs on the market today contain at least one fluorine atom and fluorine can be found in all different kinds of drugs, everything from 5-Fluorouracil, a widely used cancer treatment, to Prozac to Celebrex.
"It's a small atom with a big ego," said Prakash, referring to the fact that while fluorine is about the same size as a tiny hydrogen atom, so similar that living cells cannot tell the two elements apart, it is also extremely electronegative - it has a strong attraction for electrons - making carbon-fluorine chemical bond quite strong, which improves the bioavailability of drugs made with fluorine.
The discovery was the product of many years of trial-and-error tests, hard work that post-docs performed under Prakash's direction. Eventually, the team pinned down the precise conditions needed to coax the harmful fluoroform (CF3H) into useful reagents, including the silicon-based Ruppert-Prakash Reagent for efficient CF3 transfer.
Fluoroform with elemental sulfur was also converted to trifluoromethanesulfonic acid, a widely used superacid one-hundred times stronger than sulfuric acid.
"In real estate, everything is 'location, location, location.' In chemistry, it is 'conditions, conditions, conditions,'" Prakash said.