F&M Stories

In a rare event for any liberal arts college, a Franklin & Marshall chemistry professor and her two students made a scientific discovery that is now a commercial product.

That discovery started with Assistant Professor of Chemistry Sarah Tasker's observation:

"When I added a new reagent, bubbles formed; I wasn't expecting that, but thought they were important," says a beaming Tasker, explaining shorthand the process of science research.

For Tasker and her students, Katie DeSimone and Lyla Naqvi, now '23 graduates, the process began with failure before discovering and developing new molecules that release carbon monoxide (CO) gas in a controlled way at room temperature, which makes laboratories safer places to work.

"We started off being interested in these molecules called S-aryl thioformates, and we were intending to do photochemistry, shining light on the molecules and making them enter excited and reactive states, which turned out to be a total failure," Tasker says. "But it did get me a grant."

The experience has inspired DeSimone to start a research career in pharmaceuticals.

"I learned so much during this time, especially from Dr. Tasker, who guided me through the project well and had a significant impact on my time at F&M," she says.

With the American Chemical Society Petroleum Research Fund's assistance, the researchers went back into the lab in August 2021.

"We added an amine base and all of sudden noticed there were bubbles. We're like, 'Why the heck are there bubbles?' In this reaction, there shouldn't be any bubbles," she remembers.

As any scientist knows, observing the unexpected in research is, well, science.

"It was a totally serendipitous discovery," Tasker says. "It turns out that when you treat these very simple molecules with a very simple base at room temperature, they react to release carbon monoxide gas, making them an example of a CORM, or CO-releasing molecule."

They dubbed the thioformate molecules "thioCORMates", and worked to optimize and control the CO release. Tasker explains why this is important.

"It's a dangerous gas because it binds to the hemoglobin in our red blood cells and stops oxygen from getting to our cells," Tasker says. "For labs that want to use carbon monoxide, the standard way is to have a tank, like a big tank in the corner of your lab, and you can open the tank when you need some carbon monoxide. But that has real safety concerns."

She recalls an incident at the Massachusetts Institute of Technology, where she earned her doctorate in organic chemistry. There a CO tank valve was accidently sheared off and the entire building was evacuated for several hours.

"It can be annoying and a danger to use," Tasker says. "However, CO is very useful in research—it's used in biological studies for protein binding, in inorganic chemistry to make new complexes with metals and in organic chemistry for carbon—carbon bond-forming reactions used in the synthesis of pharmaceuticals and other important compounds. It's a really incredible gas."

Tasker's team is not the first to develop CO-releasing molecules, but their thioCORMates are superior to existing technology—they work rapidly at room temperature, and with far fewer atoms needed to carry the CO, they're easier and cheaper to synthesize as a reagent.

For Lyla Naqvi, one of the two chemistry students involved in the research and co-author with Katie DeSimone and Tasker of their paper published last year, the experience has altered her post-graduate plans.

"I've always wanted to pursue a career in medicine, but this research experience has discovered that I am also interested in medical research," Naqvi says. "As a result, I have decided to use my gap year to pursue medical research jobs so that I can further explore my passion for both scientific research and medicine."

DeSimone says, "This research heavily influenced my career path. It helped me gain so much love for being in the lab and helped me realize that I want to go to graduate school to continue research in organic chemistry."

Tasker informed Sigma-Aldrich, one of the top fine-chemical suppliers in the United States, about their discovery and the company has started commercializing the F&M team's reagents.

"It's quite unusual in the field of organic chemistry to discover new reagents and processes worth commercializing," Tasker says.

The thioCORMates are useful for the smaller quantities of CO needed for laboratory research (Tasker's team produced up to 130 milliliters), not for industrial processes; at large scale, CORMs are not cost effective.

And the change starts close to home. Tasker's colleague, Associate Professor of Chemistry Christine Piro, has replaced her CO tank in the corner with CORMs for protein-binding studies, which makes her lab safer.

For more information, see the Tasker Lab website.