Two publications from this lab, in 2011 and 2012, used mass spectrometry to show that the rates of reactions in microdroplets are accelerated by many orders of magnitude. These experiments used ordinary organic solvents and demonstrated that acceleration occurs at the solution/air interface.  These observations were then extended to a range of classical organic reactions. The Zare group showed reaction acceleration in aqueous microdroplets, for oxidation and other reactions.  

This presentation covers three topics. (i) Mechanism of acceleration which involves reduction in ΔG^# by partial solvation of reagents at the interface (solvation is greater for reagents than the transition state in bimolecular reactions, so increasing rate constants) as well as highly reactive species derived from water radical cation, H₂O^+.. (ii) Applications of reaction acceleration in high throughput (HT) chemical analysis and (iii) applications of reaction acceleration in materials and organic synthesis, e.g. for nanoparticle formation and heterocyclics synthesis including sustainable organic synthesis. Scale-up (g/h) and small-scale high-throughput reactions (1 Hz) (Figure). Thousands of new compounds are generated per hour allowing rapid screening, collection, and bioactivity testing of nanogram amounts of new drug analogs in a direct-to-biology (D2B) mode, so avoiding time consuming purification.