A team of chemists from the University of Maryland has uncovered a new method to create carbenes, a class of highly reactive molecules essential to many chemical reactions, including the formation of carbohydrates.
These molecules are vital for the building blocks of life on Earth—and potentially in space.
The researchers successfully created a carbene called hydroxymethylene (HCOH) by breaking down methanol, a common industrial chemical, using ultraviolet (UV) radiation.
Their findings were published in the Journal of the American Chemical Society.
“It’s surprising to see this carbene come from such a commonplace molecule like methanol—we have squirt bottles of it in labs everywhere,” said Leah Dodson, an assistant professor of Chemistry and Biochemistry at UMD and the senior author of the paper. “193-nanometer wavelength UV lasers are also fairly standard.
This means that carbenes could be naturally forming in places like space, where there is a lot of methanol and ultraviolet radiation. And further reactions of carbenes formed in space through this process could lead to biomolecules that make up life.”
The study’s lead author, Emily Hockey, explained that the research provides clues about how carbenes form and react on Earth, shedding light on their potential to create sugars necessary for life.
“There’s established research that suggests that HCOH can react to form simple sugars, including some that have previously been detected in space.
We think it’s possible that this carbene, since it comes from a molecule that’s so ubiquitous in space and can be detected anywhere, is the missing piece bridging gaps in our knowledge of how methanol and simple sugars can lead to bigger, more advanced biomolecules,” Hockey said.
Carbenes are typically short-lived and highly reactive, making them difficult to study. However, the UMD team’s novel method allowed them to observe the formation and decay of HCOH over millisecond timescales. Surprisingly, they found that HCOH reacted relatively slowly with oxygen at room temperature.
“When we looked at HCOH’s reactivity in our room temperature system, we saw that it decayed within 15 milliseconds,” Hockey explained.
“What’s interesting is that because carbenes are thought to be a super reactive species, it’s reasonable to assume that this carbene would react so quickly to something like oxygen that it’s impossible to catch. But that’s not what happened.”
The researchers believe their method will help astronomers and astrochemists gain new insights into the origins of life and how it may have evolved differently in space.
They plan to further investigate methanol’s breakdown and quantify the different products yielded by its reaction to UV light.
“We know that carbenes like HCOH are formed during our process, but we’d like to dig deeper into what percentage of it ends up as formaldehyde, methylene, or other hydrocarbon radicals,” Hockey explained.
Understanding the types and amounts of products created by breaking down methanol with UV radiation would provide astronomers and astrochemists with a more accurate view of how life evolved from these molecules.
“If the existing data on what is produced from methanol photodissociation are wrong, then the models being propagated will be incorrect as well—and our understanding of how life evolved from these molecules could also be compromised,” Dodson said.
“Our follow-up work will hopefully lay the groundwork for those types of simulations.”
