Single-Molecule Solvolysis Reaction Dynamics under Electrostatic Catalysis and Proton Tunneling.

Abstract

A central goal of chemical mechanism research is to provide a comprehensive interpretation of chemical reaction pathways to clarify the evolution patterns of reactions. In this work, we present an unprecedented comprehensive monitoring of the elementary reaction pathways of the S_N1 solvolysis on an in situ real-time single-molecule electrical detection platform. Through precise control of oriented external electric fields, we capture two short-lived protonated intermediates at the single-molecule level and elucidate their roles in the reaction. Both temperature- and isotope-dependent experiments, in combination with theoretical simulations, reveal crucial roles for the hydrogen-bonded acetic-acid-mediated triple-proton-transfer and the proton tunneling effect in the interconversion of these two intermediates. This work highlights the precise manipulation of chemical reactions by electrostatic fields and opens up a universal route to discover unknown intermediates or novel phenomena in the processes of material transformation and life activities.