For decades, key steps in chemical reactions occurred too fast to observe, hindering optimization of processes vital for drug and material synthesis. A study published today in National Science Review unveils a graphene-based chip that films reactions with nanosecond resolution—1000 times faster than existing methods.
Using this technique, researchers captured elusive intermediates in the Morita-Baylis-Hillman (MBH) reaction, a widely used but inefficient carbon-bond-forming reaction. Real-time tracking revealed two proton transfer pathways: a concerted "shuttle" route (kinetic path) and a dominant stepwise process (thermodynamic path). Surprisingly, the reaction exhibited an oscillatory behavior driven by energy feedback loops at the single-molecule level, showing complexity emerging on a molecular scale.
The electric field applied by the chip dramatically accelerated the reaction, achieving a turnover frequency of 5,000 reactions per second—a huge increase over conventional methods. Scaling this approach, the team synthesized multiple compounds within an hour using densely integrated molecular devices and the products were characterized by mass spectra, paving the way for energy-efficient on-chip chemical manufacturing.
"This is like installing high-speed cameras next to molecules," said lead author Xuefeng Guo. "By seeing reaction dynamics directly, we can rationally design catalysts and green synthesis protocols."
National Science Review
Experimental study