Effective screening of Coulomb repulsions in water accelerates reactions of like-charged compounds by orders of magnitude

The reaction kinetics between like-charged compounds in water is extremely slow due to Coulomb repulsions. This paper demonstrates that screening these interactions, and consequently increasing the local concentration of reactants, boosts reactions by many orders of magnitude. Using cationic micelles, the reaction between negatively charged Coenzyme A molecules accelerates approximately 5 million-fold—10⁶ times faster kinetics than in 0.5 M NaCl, despite the salt being ∼10³ more concentrated. Rate enhancements extend beyond micelles, as evidenced by significant catalytic effects (10⁴–10⁵-fold) from other highly charged species like oligomers and polymers. The phenomenon is generalized by analogously speeding up non-covalent complex formation—DNA hybridization. A theoretical analysis shows that acceleration correlates with the catalysts’ surface charge density in both experimental systems, enabling prediction and control of reaction rates of like-charged compounds with counter-charged species.

Adam Kowalski, Krzysztof Bielec, Grzegorz Bubak, Pawel J. Żuk, Maciej Czajkowski, Volodymyr Sashuk, Wilhelm T. S. Huck, Jan M. Antosiewicz, Robert Holyst