Unstable radicals zapped into action

Abstract

Chemists can couple short-lived radicals to make myriad types of molecules, thanks to a microfluidic electrochemical cell that places the anode and the cathode just 25 µm apart. The new device offers an alternative to photoredox chemistry, which generates and couples transient radicals in solution using light and a chemical catalyst. “We’re trying to give synthetic chemists an alternative way of getting these important intermediates,” says Stephen L. Buchwald, a chemist at the Massachusetts Institute of Technology who led the research effort with Klavs F. Jensen, an MIT chemical engineer. The microfluidic electrochemical cell features a fluorinated ethylene propylene film sandwiched between two glassy carbon electrodes. The electrodes are 25 µm apart, creating a microfluidic channel for the reagents to pass through (Science 2020, DOI: 10.1126/science.aba3823). This slim space is critical, the researchers say, because persistent radicals generated at one electrode don’t have far to travel to meet up with