Researchers at the University of Illinois have developed a sustainable method for forming carbon-carbon bonds without the need for expensive and rare metal catalysts. The interdisciplinary team of plasma engineers, chemists, and bioengineers used electricity and a plasma-liquid process to generate solvated electrons, which were then used to facilitate carbon-carbon bond formation in a pinacol coupling reaction. Carbon-carbon bond formation is a crucial process in the production of various organic compounds, including pharmaceuticals and plastics.
Traditionally, carbon-carbon bond formation requires the use of metal reagents or catalysts, which can be costly, scarce, and pose safety and environmental concerns. In contrast, the newly developed process only requires electricity and a simple electrolysis reactor. The electrons needed for the reaction are generated from argon gas and injected into the solution, creating solvated electrons. The researchers highlight the potential for using renewable energy sources such as wind, solar, or nuclear power to provide the electricity, making the entire process sustainable.
Collaboration played a key role in the success of the project. The expertise of the plasma engineering team, led by R. Mohan Sankaran, was complemented by the chemistry and materials science knowledge of Jeffrey S. Moore's group. Jian Wang, a postdoctoral associate in Moore's group, conducted experiments with different organic substrates, characterizing reactions and selecting pinacol coupling as the focus of the study. Matthew Confer, a postdoctoral researcher in Rohit Bhargava's group, contributed computational chemistry expertise to model the reaction pathways.
The researchers emphasize that their approach represents a significant advancement in the field of organic chemistry. While previous studies have used plasmas for organic reactions, they typically involved oxidation processes, whereas this study focuses on reduction reactions and carbon-carbon bond formation using solvated electrons.
The team plans to apply their process to other organic chemistry reactions to demonstrate its versatility. They also aim to address limitations in yield caused by mass transfer issues by incorporating liquid flow into the system. This addition would enhance mass transport and potentially enable continuous production of the desired products. Furthermore, the researchers acknowledge that the controllability and selectivity of their plasma electrochemistry method can be further improved compared to traditional metal-catalyzed or electro- and photocatalytic chemistries, and they are actively working towards achieving these goals.
Source: University of Illinois at Urbana-Champaign, College of Liberal Arts and Sciences