Reaction acceleration at air‐solution interfaces: Anisotropic rate constants for Katritzky transamination
Abstract
To disentangle the factors controlling the rates of accelerated reactions in droplets, we used mass spectrometry to study the Katritzky transamination in levitated Leidenfrost droplets of different yet constant volumes over a range of concentrations while holding concentration constant by adding back the evaporated solvent. The set of concentration and droplet volume data indicates that the reaction rate in the surface region is much higher than that in the interior. These same effects of concentration and volume were also seen in bulk solutions. Three pyrylium reagents with different surface activity showed differences in transamination reactivity. The conclusion is drawn that reactions with surface‐active reactants are subject to greater acceleration, as seen particularly at lower concentrations in systems of higher surface‐to‐volume ratios. These results highlight the key role that air‐solution interfaces play in Katritzky reaction acceleration. They are also consistent with the view that reaction‐increased rate constant is at least in part due to limited solvation of reagents at the interface.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 20, 2020
- Source ID
- 10.1002/jms.4585
Entities
People
- R. Graham Cooks
- Tsdale F. Mehari
- Yangjie Li
- Yong Liu
- Zhenwei Wei
Organizations
- Defense Advanced Research Projects Agency
- MSD (United Kingdom)
- National Science Foundation
- Purdue University