New nitrogen products are in the air

The discovery comes from a team of Yale chemists who found a way to combine atmospheric nitrogen with benzene to make a chemical compound called aniline, which is a precursor to materials used to make an assortment of synthetic products.

A study describing the process appears in the journal Nature.

"In the long run, we hope to learn how to use the abundant nitrogen in the air as a resource for synthesizing the products needed by society," said Yale chemistry professor Patrick Holland, senior author of the study.

Much attention has been focused on "nitrogen fixation," a process by which atmospheric nitrogen is used to create ammonia. But as Holland and his colleagues point out, there are many other compounds, materials, and processes that could use nitrogen in other forms -- if researchers can find ways to make them with atmospheric nitrogen.

Holland said previous attempts by other researchers to combine atmospheric nitrogen and benzene failed. Those attempts used highly reactive derivatives of benzene that would degrade before they could produce a chemical reaction with nitrogen.

Holland and his colleagues used an iron compound to break down one of the chemical bonds in benzene. They also treated the nitrogen with a silicon compound that allowed the nitrogen to combine with benzene.

"Fundamentally, we're showing a new way of thinking about how to encourage nitrogen to form new bonds that may be adaptable to making other products," Holland said.

Co-first authors of the study are Sean McWilliams, who recently received a Ph.D. from Yale and is now doing postdoctoral work at the University of North Carolina, and Daniel Broere, a former postdoctoral fellow in Holland's lab who is now an assistant professor at Utrecht University. Co-authors of the study are Samuel Bhutto and Brandon Mercado of Yale, and Connor Halliday of the University of Edinburgh.

Funding for the study came, in part, from the National Institutes of Health and the U.S. Department of Energy.