Fluctuation-driven chemistry at aqueous interfaces and beyond

Interfacial electric fields at gas–water, oil–water, and solid–water boundaries are frequently invoked to explain radical formation under ambient conditions. Field strengths of 107–109 V m-1 are often cited as sufficient for this purpose. Yet the electrostatic work accessible from such fields over molecular distances is orders of magnitude smaller than the energies required for homolytic bond dissociation or one-electron ionization. This discrepancy raises the question of whether interfacial electric fields directly drive chemistry or modulate an intrinsic mechanism of liquid water. We argue that equilibrium interfacial electric fields bias molecular orientation and reaction kinetics but do not constitute a primary energetic input for bond-breaking chemistry. Instead, we propose a fluctuation-driven model in which transient, partially charge-separated configurations (H2O+δ···H2O-δ) arise from cooperative hydrogenbond fluctuations. In this picture, interfaces, ions, and weak perturbations reshape the free-energy landscape and alter fluctuation statistics.