Electroprecipitating the Sulfate Radical Anion Amplifies Electrochemiluminescence in Space and Time.

We have discovered a strategy to synthesize reactive radical salts, effectively bottling up radicals in space and time for future use. We apply this new principle to electrochemiluminescence (ECL) through the simultaneous electro-reduction of peroxydisulfate, SO, and tris(bipyridine)ruthenium(II), [Ru(bpy)] in a water/acetonitrile mixture. The electrode generates a concentration profile exceeding the solubility of the cation and anion pair, promoting precipitation.

Quantifying the interfacial tension of adsorbed droplets on electrified interfaces.

Hypothesis: This paper develops a new measurement method to answer the question: How does one measure the interfacial tension of adsorbed droplets?

Experiments: This measurement is based on the placement of a bubble at a water|organic interface. To prove the concept, a bubble was formed by pipetting gas below the water|1,2-dichloroethane interface. Our values agree well with previous reports.

Through-Space Electrochemiluminescence Reveals Bubble Forces at Remote Phase Boundaries.

Several groups have reported on the curious chemistry and reaction acceleration in confined volumes. These complex multiphase systems most closely resemble natural processes, and new measurement tools are necessary to probe chemistry in such environments. Generally, electrochemiluminescence (ECL) reports on processes immediately near (within a few micrometers) the electrode surface.

Phase-Resolved Electrochemiluminescence with a Single Luminophore.

Multiphase chemical systems are greatly different than bulk solutions, as they provide a unique environment for reactions to proceed and have unique physicochemical properties. Thus, new tools need to be developed to gain a more detailed understanding of these systems. Here, we use electrogenerated chemiluminescence (ECL) to elucidate phase boundaries precisely and comprehensively between aqueous droplets and an organic continuous phase owing to ECL's unprecedented spatial resolution (a few micrometers) confined at the electrode surface.