Chemistry-Induced Mobility in Catalytic Chemical Reactions

With a standard pulse-field gradient nuclear magnetic resonance based diffusion ordered spectroscopy (DOSY), we measure chemical-shift specific molecular diffusivity simultaneously with reaction kinetics in situ as reaction progresses. In simple exothermic, catalysed chemical reactions, we observe unexpected solvent enhanced diffusion, both in water and in organic solvents, to be tightly correlated with molecular catalytic cycles. Scaling analysis suggests the critical role of hydrodynamic coupling at nanoscale among “force-dipole-like” chemical reaction centers. The observation of chemistry-induced mobility challenges the simple “passive” picture of chemical reaction, suggesting rich energy dissipation pathways that eventually lead to collective consequences, for example, a counterintuitive antichemotaxis flux, revealed from a gradient microfluidic chip measurement.